U.S. patent application number 16/058546 was filed with the patent office on 2019-02-07 for high power laser hydraulic fracturing, stimulation, tools systems and methods.
This patent application is currently assigned to Foro Energy, Inc.. The applicant listed for this patent is Foro Energy, Inc.. Invention is credited to Ronald A. De Witt, Paul D. Deutch, John Ely, Brian O. Faircloth, Fred C. Kellermann, John Yearwood, Mark S. Zediker, Tom Zimmerman.
Application Number | 20190040726 16/058546 |
Document ID | / |
Family ID | 50731830 |
Filed Date | 2019-02-07 |
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United States Patent
Application |
20190040726 |
Kind Code |
A1 |
Deutch; Paul D. ; et
al. |
February 7, 2019 |
HIGH POWER LASER HYDRAULIC FRACTURING, STIMULATION, TOOLS SYSTEMS
AND METHODS
Abstract
There are provided high power laser perforation, hydraulic
fracturing systems, tools and methods for the stimulation and
recovery of energy sources, such as hydrocarbons, from a formation.
These systems, tools and methods provide predetermined laser beam
energy patterns, to provide for the down hole volumetric removal of
custom geometries of materials, sealing of perforations,
reperorations, refractures and other downhole actives.
Inventors: |
Deutch; Paul D.; (Houston,
TX) ; Kellermann; Fred C.; (Sugar Land, TX) ;
Zimmerman; Tom; (Pearland, TX) ; Yearwood; John;
(Houston, TX) ; Zediker; Mark S.; (Castle Rock,
CO) ; De Witt; Ronald A.; (Katy, TX) ;
Faircloth; Brian O.; (Evergreen, CO) ; Ely; John;
(Montgomery, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Foro Energy, Inc. |
Houston |
TX |
US |
|
|
Assignee: |
Foro Energy, Inc.
Houston
TX
|
Family ID: |
50731830 |
Appl. No.: |
16/058546 |
Filed: |
August 8, 2018 |
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Application
Number |
Filing Date |
Patent Number |
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14082026 |
Nov 15, 2013 |
10053967 |
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16058546 |
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13782869 |
Mar 1, 2013 |
9719302 |
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14082026 |
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13222931 |
Aug 31, 2011 |
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13782869 |
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13210581 |
Aug 16, 2011 |
8662160 |
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14082026 |
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12543986 |
Aug 19, 2009 |
8826973 |
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13210581 |
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61727096 |
Nov 15, 2012 |
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61786687 |
Mar 15, 2013 |
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61378910 |
Aug 31, 2010 |
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61090384 |
Aug 20, 2008 |
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61102730 |
Oct 3, 2008 |
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61106472 |
Oct 17, 2008 |
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61153271 |
Feb 17, 2009 |
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61798875 |
Mar 15, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/26 20130101;
E21B 43/11 20130101; E21B 43/119 20130101 |
International
Class: |
E21B 43/26 20060101
E21B043/26; E21B 43/119 20060101 E21B043/119; E21B 43/11 20060101
E21B043/11 |
Claims
1.-29 (canceled)
30. A method of stimulating a well, the method comprising:
positioning a laser perforating tool in the borehole at a location
in a formation; delivering a plurality of high power laser beams,
each having not less than 10 kW of power, in a plurality of
predetermined laser beam patterns; the laser beam patterns position
at the location and extending along a length of the borehole,
wherein the position of the laser beam patterns is based at least
in part upon a stress plane in the formation; whereby each laser
beam creates a discrete volumetric removal having a predetermined
shape defining a laser perforation; and, flowing a fracturing fluid
under pressure down the borehole, through the laser perforation and
into the formation, whereby the formation is hydraulically
fractured.
31. The method of claim 30, wherein the shape of the laser beam
patterns is predetermined at least in part to reduce near borehole
tortuosity.
32. (canceled)
33. The method of claim 30, wherein the shape of the laser beam
patterns is predetermined at least in part to reduce near borehole
tortuosity and the position of the laser beam patterns is based at
least in part to reduce near well bore tortuosity.
34. The method of claim 30, wherein the shape of the laser beam
patterns is at least in part reduces near borehole tortuosity.
35. (canceled)
36. The method of claim 30, wherein the shape of the laser beam
patterns is at least in part essentially eliminates near borehole
tortuosity.
37. The method of claim 30, wherein the position of the laser beam
patterns at least in part essentially eliminates near borehole
tortuosity.
38. The method of claim 30, wherein the shape of the laser beam
patterns is at least in part essentially eliminates the adverse
flow characteristics associated with near borehole tortuosity.
39. The method of claim 30, wherein the position of the laser beam
patterns at least in part essentially eliminates the adverse flow
characteristics associated with near borehole tortuosity.
40. The method of claim 30, wherein the shape of the laser beam
patterns is predetermined at least in part to reduce near borehole
tortuosity and the position of the laser beam patterns is based at
least in part to reduce near well bore tortuosity.
41. (canceled)
42. (canceled)
43. (canceled)
44. (canceled)
45. (canceled)
46. The method of claim 32, wherein the location along the borehole
is at not less than 5,000 feet measured depth depth and the laser
beam has a power of not less than 10 kW.
47. (canceled)
48. The method of claim 45, wherein the laser perforating tool
comprises a tractor section, and a laser cutting head section.
49. (canceled)
50. The method of claim 30, wherein the laser perforating tool
comprises a tractor section, a laser cutting head section, and a
means to axially extend the laser cutting head section; and the
means to axially extend the laser cutting section comprises a motor
a controller and an advancement screw.
51. (canceled)
52. (canceled)
53. (canceled)
54. (canceled)
55. (canceled)
56. (canceled)
57. (canceled)
58. (canceled)
59. (canceled)
60. (canceled)
61. (canceled)
62. (canceled)
63. (canceled)
64. (canceled)
65. The method of claim 30, wherein the shape of the laser beam
patterns at least in part essentially eliminates the adverse flow
characteristics associated with near borehole tortuosity.
66. A method of stimulating a well, the method comprising:
positioning a laser beam delivery head in the borehole at a
location in a formation, the location being at a measured depth of
not less than 5,000 ft; delivering a plurality of high power laser
beams, each having at not less than 10 kW of power, in a plurality
of predetermined laser beam patterns; the laser beam patterns
positioned at the location and extending along a length of the
borehole, wherein the position of the laser beam patterns is based
at least in part upon a stress plane in the formation; whereby each
laser beam creates a discrete volumetric removal having a
predetermined shape defining a laser perforation; and, flowing a
fracturing fluid under pressure down the borehole, through the
laser perforation and into the formation, whereby the formation is
hydraulically fractured.
67. The method of claim 66, wherein the stress plane is a preferred
stress plane.
68. The method of claim 66, wherein the identified stress comprises
a preferred stress plane and at least one volumetric removal
follows the preferred stress plane.
69. (canceled)
70. (canceled)
71. (canceled)
72. The method of claim 66, wherein at least one volumetric removal
follows the stress plane.
73. (canceled)
74. The method of claim 66, wherein at least one volumetric removal
is positioned in and parallel with the preferred stress plane.
75. (canceled)
76. The method of claim 66, wherein the fracturing fluid is slick
water.
77. (canceled)
78. The method of claim 76, wherein the fracturing fluid comprises
a proppant.
79. (canceled)
80. (canceled)
81. The method of claim 66, wherein the location in the borehole is
substantially horizontal.
82. The method of claim 66, wherein the borehole has a TVD of not
less than 5,000 ft, a MD of not less than 15,000 ft and a
substantially horizontal section having a length of not less than
5,000 ft.
83. (canceled)
84. (canceled)
85. (canceled)
86. (canceled)
87. (canceled)
88. The method of claim 66, wherein at least one volumetric removal
is in the shape of a disc having a volume removed of not less than
1 cubic inches.
89. (canceled)
90. (canceled)
91. (canceled)
92. (canceled)
93. The method of claim 66, wherein at least one volumetric removal
is in the shape of a disc having a volume removed of not less than
7 cubic inches.
94. The method of claim 66, wherein the volumetric removals are in
the shape of a disc, each disc having a volume removed of not less
than 7 cubic inches.
95. The method of claim 66, wherein for each volumetric removal the
volume removed is not less than 7 cubic inches.
96. The method of claim 66, wherein for each volumetric removal the
volume removed is not less than 50 cubic inches.
97. (canceled)
98. (canceled)
99. The method of claim 82, wherein the volumetric removal is in
the shape of a disc having a volume removed of not less than 100
cubic inches.
100. The method of claim 66, wherein the plurality of volumetric
removals comprises at least four discrete shapes.
101. (canceled)
102. The method of claim 66, wherein the plurality of volumetric
removals comprises at least six discrete shapes.
103. (canceled)
104. (canceled)
105. (canceled)
106. (canceled)
107. (canceled)
108. (canceled)
109. (canceled)
110. (canceled)
111. (canceled)
112. (canceled)
113. (canceled)
114. (canceled)
115. The method of claim 66, wherein at least of one of volumetric
removal is in the shape of a rectangular slot.
116. The method of claim 66, wherein the volumetric removals are
each in the shape of a rectangular slot.
117. The method of claim 66, wherein at least one volumetric
removal is in the shape of a rectangular slot having a volume
removed of not less than 100 cubic inches.
118. The method of claim 66, wherein at least one volumetric
removal is in the shape of a rectangular slot having a volume
removed of not less than 150 cubic inches.
119. (canceled)
120. (canceled)
121. (canceled)
122. (canceled)
123-179. (canceled)
180. A method of laser hydraulic fracturing a well, the method
comprising: positioning a laser perforating tool in the borehole at
a location in a formation; delivering a plurality of high power
laser beams each having not less than 10 kW of power in a plurality
of predetermined laser beam patterns, the laser beam patterns
position at the location and extending along a length of the
borehole, wherein the position of the laser beam patterns is based
at least in part upon a stress plane in the formation; whereby each
laser beam creates a discrete volumetric removal having a
predetermined shape defining a laser perforation; and, flowing a
fracturing fluid under pressure down the borehole, through the
laser perforation and into the formation, whereby the formation is
hydraulically fractured.
181. The method of claim 180, wherein each laser perforation
defines an opening in a casing in the borehole, wherein each
opening is a circle, and wherein the diameters of each opening vary
by no more than 2%.
182. The method of claim 180, wherein each laser perforation
defines an opening in a casing in the borehole comprising an
opening edge, wherein each opening is a circle, and wherein each
opening edge is essentially burr free.
183. The method of claim 180, wherein each laser perforation
defines an opening in a casing in the borehole comprising an
opening edge, wherein each opening is a circle, and wherein each
opening edge is essentially smooth.
184. (canceled)
185. (canceled)
186. (canceled)
187. (canceled)
188. (canceled)
189. (canceled)
190. (canceled)
191. (canceled)
192. A method of stimulating a well, the method comprising:
positioning a laser hydraulic fracturing assembly in the borehole
at a location in a formation; delivering a plurality of high power
laser beams, each having not less than 10 kW of power, in a
plurality of predetermined laser beam patterns; the laser beam
patterns positioned at the location and extending along a length of
the borehole, wherein the position of the laser beam patterns is
based at least in part upon a stress plane in the formation;
wherein the shape of the laser beam patterns is predetermined at
least in part to reduce near borehole tortuosity; and, whereby each
laser beam creates a discrete volumetric removal having a
predetermined shape defining a laser perforation.
193. (canceled)
194. (canceled)
195. (canceled)
196. (canceled)
197. (canceled)
198. (canceled)
199. (canceled)
200. (canceled)
201. (canceled)
202. (canceled)
203. (canceled)
204. (canceled)
205. A method of laser stimulating a well, the method comprising:
positioning a laser perforating tool in the borehole at a location
in a formation; delivering a plurality of high power laser beams
each having not less than 10 kW of power in a plurality of
predetermined laser beam patterns, the laser beam patterns position
at the location and extending along a length of the borehole,
wherein the position of the laser beam patterns is based at least
in part upon a stress plane in the formation; and, whereby each
laser beam creates a discrete volumetric removal having a
predetermined shape defining a laser perforation.
206. The method of claim 205, wherein each laser perforation
defines an opening in a casing in the borehole, wherein each
opening is a circle, and wherein the diameters of each opening vary
by no more than 2%.
207. The method of claim 205, wherein each laser perforation
defines an opening in a casing in the borehole comprising an
opening edge, wherein each opening is a circle, and wherein each
opening edge is essentially burr free.
208. The method of claim 205, wherein each laser perforation
defines an opening in a casing in the borehole comprising an
opening edge, wherein each opening is a circle, and wherein each
opening edge is essentially smooth.
209. The method of claim 205, wherein near borehole tortuosity is
essentially not present.
210. The method of claim 205, wherein near borehole tortuosity is
not present.
211. The method of claim 205, wherein shock sensitive instruments
are positioned downhole during laser beam delivery and provide
information regarding downhole conditions.
212. The method of claim 205, wherein shock sensitive instruments
are positioned downhole during laser beam delivery and provide
information regarding the perforations.
213. (canceled)
214. (canceled)
215. (canceled)
216-222. (canceled)
Description
[0001] This application: (i) claims, under 35 U.S.C. .sctn.
119(e)(1), the benefit of the filing date of Nov. 15, 2012 of
provisional application Ser. No. 61/727,096; (ii) claims, under 35
U.S.C. .sctn. 119(e)(1), the benefit of the filing date of Mar. 15,
2013 of provisional application Ser. No. 61/786,687; (iii) is a
continuation-in-part of U.S. patent application Ser. No.
13/782,869, filed Mar. 1, 2013; (iv) is a continuation-in-part of
U.S. patent application Ser. No. 13/222,931, filed Aug. 31, 2011,
which claims, under 35 U.S.C. .sctn. 119(e)(1), the benefit of the
filing date of Aug. 31, 2010 of provisional application Ser. No.
61/378,910 and the benefit of the filing date of Aug. 20, 2008 of
provisional application Ser. No. 61/090,384; (v) is a
continuation-in-part of Ser. No. 13/210,581; (vi) is a
continuation-in-part of Ser. No. 12/543,986, filed Aug. 19, 2009,
which claims, under 35 U.S.C. .sctn. 119(e)(1), the benefit of the
filing date of Aug. 20, 2008 of provisional application Ser. No.
61/090,384, the benefit of the filing date of Oct. 3, 2008 of
provisional application Ser. No. 61/102,730, the benefit of the
filing date of Oct. 17, 2008 of provisional application Ser. No.
61/106,472, and the benefit of the filing date of Feb. 17, 2009 of
provisional application Ser. No. 61/153,271; and (vii) claims,
under 35 U.S.C. .sctn. 119(e)(1), the benefit of the filing date of
Mar. 15, 2013 of provisional application Ser. No. 61/798,875, the
entire disclosures of each of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present inventions relate to hydraulic fracturing, well
stimulation and the recovery of energy sources using high power
laser tools. In particular, the present inventions relate to
hydrocarbon and energy recovery through high power laser hydraulic
fracturing, perforating, fracturing, and opening, increasing and
enhancing the flow of energy sources, from a formation or reservoir
into a production tubing or collection system. In addition to
improved performance and safety over conventional systems, such as
explosive based perforating guns and high pressure jetting with
solids laden fluids, the present inventions provide for the precise
and predetermined placement of laser beam energy, in precise and
predetermined energy distribution patterns, e.g., custom
geometries, custom perforations, custom fracture patterns,
volumetric removals and laser adaptive fracturing. These custom
operations can be tailored and fitted to the particular geological
and structural features of a formation, reservoir and pay zone.
Unlike conventional methods, such as explosive perforating tools
and high pressure jetting with solids laden fluids, the laser beam
and laser process can be controlled or operated in a manner that
provides numerous advantages, such as for example, increase
control, custom volumetric removals and geometries, adaptive
volumetric removals and geometries, maintaining and enhancing the
porosity, openness and structure of the inner surface of the
openings.
[0003] As used herein, unless specified otherwise "high power laser
energy" means a laser beam having at least about 1 kW (kilowatt) of
power. As used herein, unless specified otherwise "great distances"
means at least about 500 m (meter). As used herein, unless
specified otherwise, the term "substantial loss of power,"
"substantial power loss" and similar such phrases, mean a loss of
power of more than about 3.0 dB/km (decibel/kilometer) for a
selected wavelength. As used herein the term "substantial power
transmission" means at least about 50% transmittance.
[0004] As used herein, unless specified otherwise, "optical
connector", "fiber optics connector", "connector" and similar terms
should be given their broadest possible meanings and include any
component from which a laser beam is or can be propagated, any
component into which a laser beam can be propagated, and any
component that propagates, receives or both a laser beam in
relation to, e.g., free space, (which would include a vacuum, a
gas, a liquid, a foam and other non-optical component materials),
an optical component, a wave guide, a fiber, and combinations of
the forgoing.
[0005] As used herein, unless specified otherwise, the term "earth"
should be given its broadest possible meaning, and includes, the
ground, all natural materials, such as rocks, and artificial
materials, such as concrete, that are or may be found in the
ground, including without limitation rock layer formations, such
as, granite, basalt, sandstone, dolomite, sand, salt, limestone,
rhyolite, quartzite and shale rock.
[0006] As used herein, unless specified otherwise, the term
"borehole" should be given it broadest possible meaning and
includes any opening that is created in a material, a work piece, a
surface, the earth, a structure (e.g., building, protected military
installation, nuclear plant, offshore platform, or ship), or in a
structure in the ground, (e.g., foundation, roadway, airstrip, cave
or subterranean structure) that is substantially longer than it is
wide, such as a well, a well bore, a well hole, a micro hole,
slimhole and other terms commonly used or known in the arts to
define these types of narrow long passages. Wells would further
include exploratory, production, abandoned, reentered, reworked,
and injection wells, and cased and uncased or open holes. Although
boreholes are generally oriented substantially vertically, they may
also be oriented on an angle from vertical, to and including
horizontal. Thus, using a vertical line, based upon a level as a
reference point, a borehole can have orientations ranging from
0.degree. i.e., vertical, to 90.degree., i.e., horizontal and
greater than 90.degree. e.g., such as a heel and toe, and
combinations of these such as for example "U" and "Y" shapes; there
may also be for example multilateral boreholes in a fishbone
pattern, and multilateral horizontal boreholes initiated at
different levels in the earth from the mother bore. Boreholes may
further have segments or sections that have different orientations,
they may have straight sections and arcuate sections and
combinations thereof; and for example may be of the shapes commonly
found when directional drilling is employed. Thus, as used herein
unless expressly provided otherwise, the "bottom" of a borehole,
the "bottom surface" of the borehole and similar terms refer to the
end of the borehole, i.e., that portion of the borehole furthest
along the path of the borehole from the borehole's opening, the
surface of the earth, or the borehole's beginning. The terms "side"
and "wall" of a borehole should to be given their broadest possible
meaning and include the longitudinal surfaces of the borehole,
whether or not casing or a liner is present, as such, these terms
would include the sides of an open borehole or the sides of the
casing that has been positioned within a borehole. Boreholes may be
made up of a single passage, multiple passages, connected passages
and combinations thereof, in a situation where multiple boreholes
are connected or interconnected each borehole would have a borehole
bottom. Boreholes may be formed in the sea floor, under bodies of
water, on land, in ice formations, or in other locations and
settings.
[0007] Boreholes are generally formed and advanced by using
mechanical drilling equipment having a rotating drilling tool,
e.g., a bit. For example and in general, when creating a borehole
in the earth, a drilling bit is extending to and into the earth and
rotated to create a hole in the earth. In general, to perform the
drilling operation the bit must be forced against the material to
be removed with a sufficient force to exceed the shear strength,
compressive strength or combinations thereof, of that material.
Thus, in conventional drilling activity mechanical forces exceeding
these strengths of the rock or earth must be applied. The material
that is cut from the earth is generally known as cuttings, e.g.,
waste, which may be chips of rock, dust, rock fibers and other
types of materials and structures that may be created by the bit's
interactions with the earth. These cuttings are typically removed
from the borehole by the use of fluids, which fluids can be
liquids, foams or gases, or other materials know to the art.
[0008] As used herein, unless specified otherwise, the term
"advancing" a borehole should be given its broadest possible
meaning and includes increasing the length of the borehole. Thus,
by advancing a borehole, provided the orientation is less than
90.degree. the depth of the borehole may also increased. The true
vertical depth ("TVD") of a borehole is the distance from the top
or surface of the borehole to the depth at which the bottom of the
borehole is located, measured along a straight vertical line. The
measured depth ("MD") of a borehole is the distance as measured
along the actual path of the borehole from the top or surface to
the bottom. As used herein unless specified otherwise the term
depth of a borehole will refer to MD. In general, a point of
reference may be used for the top of the borehole, such as the
rotary table, drill floor, well head or initial opening or surface
of the structure in which the borehole is placed.
[0009] As used herein, unless specified otherwise, the term "drill
pipe" is to be given its broadest possible meaning and includes all
forms of pipe used for drilling activities; and refers to a single
section or piece of pipe. As used herein the terms "stand of drill
pipe," "drill pipe stand," "stand of pipe," "stand" and similar
type terms should be given their broadest possible meaning and
include two, three or four sections of drill pipe that have been
connected, e.g., joined together, typically by joints having
threaded connections. As used herein the terms "drill string,"
"string," "string of drill pipe," string of pipe" and similar type
terms should be given their broadest definition and would include a
stand or stands joined together for the purpose of being employed
in a borehole. Thus, a drill string could include many stands and
many hundreds of sections of drill pipe.
[0010] As used herein, unless specified otherwise, the term
"tubular" is to be given its broadest possible meaning and includes
drill pipe, casing, riser, coiled tube, composite tube, vacuum
insulated tubing ("VIT), production tubing and any similar
structures having at least one channel therein that are, or could
be used, in the drilling industry. As used herein the term "joint"
is to be given its broadest possible meaning and includes all types
of devices, systems, methods, structures and components used to
connect tubulars together, such as for example, threaded pipe
joints and bolted flanges. For drill pipe joints, the joint section
typically has a thicker wall than the rest of the drill pipe. As
used herein the thickness of the wall of tubular is the thickness
of the material between the internal diameter of the tubular and
the external diameter of the tubular.
[0011] As used herein, unless specified otherwise, the terms
"blowout preventer," "BOP," and "BOP stack" should be given their
broadest possible meanings, and include: (i) devices positioned at
or near the borehole surface, e.g., the surface of the earth
including dry land or the seafloor, which are used to contain or
manage pressures or flows associated with a borehole; (ii) devices
for containing or managing pressures or flows in a borehole that
are associated with a subsea riser or a connector; (iii) devices
having any number and combination of gates, valves or elastomeric
packers for controlling or managing borehole pressures or flows;
(iv) a subsea BOP stack, which stack could contain, for example,
ram shears, pipe rams, blind rams and annular preventers; and, (v)
other such similar combinations and assemblies of flow and pressure
management devices to control borehole pressures, flows or both
and, in particular, to control or manage emergency flow or pressure
situations.
[0012] As used herein, unless specified otherwise, the terms
"removal of material," "removing material," "remove" and similar
such terms should be given their broadest possible meanings. Thus,
such terms would include melting, flowing, vaporization, softening,
laser induced break down, ablation; as well as, combinations and
variations of these, and other processes and phenomena that can
occur when directed energy from a laser beam is delivered to a
material, object or work surface. Such terms would further include
combinations of the forgoing laser induced processes and phenomena
with the energy that the fluid jet imparts to the material to be
cut. Moreover, irrespective of the processes or phenomena taking
place, such terms would include the lessening, opening, cutting,
severing or sectioning of the material, object or targeted
structure.
[0013] As used herein, unless specified otherwise, the terms
"workover," "completion" and "workover and completion" and similar
such terms should be given their broadest possible meanings and
would include activities that place at or near the completion of
drilling a well, activities that take place at or the near the
commencement of production from the well, activities that take
place on the well when the well is a producing or operating well,
activities that take place to reopen or reenter an abandoned or
plugged well or branch of a well, and would also include for
example, perforating, cementing, acidizing, fracturing, pressure
testing, the removal of well debris, removal of plugs, insertion or
replacement of production tubing, forming windows in casing to
drill or complete lateral or branch wellbores, cutting and milling
operations in general, insertion of screens, stimulating, cleaning,
testing, analyzing and other such activities. These terms would
further include applying heat, directed energy, preferably in the
form of a high power laser beam to heat, melt, soften, activate,
vaporize, disengage, desiccate and combinations and variations of
these, materials in a well, or other structure, to remove, assist
in their removal, cleanout, condition and combinations and
variation of these, such materials.
[0014] As used herein, unless specified otherwise, the terms
"conveyance structure", "umbilical", "line structure" and similar
such terms should be given their broadest possible meanings and may
be, contain or be optically or mechanically associated with: a
single high power optical fiber; a single high power optical fiber
that has shielding; a single high power optical fiber that has
multiple layers of shielding; two, three or more high power optical
fibers that are surrounded by a single protective layer, and each
fiber may additionally have its own protective layer; a fiber
support structure which may be integral with or releasable or
fixedly attached to an optical fiber (e.g., a shielded optical
fiber is clipped to the exterior of a metal cable and lowered by
the cable into a borehole); other conduits such as a conduit to
carry materials to assist a laser cutter, for example gas, air,
nitrogen, oxygen, inert gases; other optical fibers or metal wires
for the transmission of data and control information and signals;
and any combinations and variations thereof.
[0015] The conveyance structure transmits high power laser energy
from the laser to a location where high power laser energy is to be
utilized or a high power laser activity is to be performed by, for
example, a high power laser tool. The conveyance structure may, and
preferably in some applications does, also serve as a conveyance
device for the high power laser tool. The conveyance structure's
design or configuration may range from a single optical fiber, to a
simple to complex arrangement of fibers, support cables, shielding
on other structures, depending upon such factors as the
environmental conditions of use, performance requirements for the
laser process, safety requirements, tool requirements both laser
and non-laser support materials, tool function(s), power
requirements, information and data gathering and transmitting
requirements, control requirements, and combinations and variations
of these.
[0016] Preferably, the conveyance structure may be coiled tubing, a
tube within the coiled tubing, jointed drill pipe, jointed drill
pipe having a pipe within a pipe, or may be any other type of line
structure, that has a high power optical fiber associated with it.
As used herein the term "line structure" should be given its
broadest meaning, unless specifically stated otherwise, and would
include without limitation: wireline; coiled tubing; slick line;
logging cable; cable structures used for completion, workover,
drilling, seismic, sensing, and logging; cable structures used for
subsea completion and other subsea activities; umbilicals; cables
structures used for scale removal, wax removal, pipe cleaning,
casing cleaning, cleaning of other tubulars; cables used for ROV
control power and data transmission; lines structures made from
steel, wire and composite materials, such as carbon fiber, wire and
mesh; line structures used for monitoring and evaluating pipeline
and boreholes; and would include without limitation such structures
as Power & Data Composite Coiled Tubing (PDT-COIL) and
structures such as Smart Pipe.RTM. and FLATpak.RTM..
[0017] Drilling Wells, Perforating and Hydraulic Fracturing
[0018] In the production of natural resources from formations,
reservoirs, deposits, or locations within the earth a well or
borehole is drilled into the earth to the location where the
natural resource is believed to be located. These natural resources
may be a hydrocarbon reservoir, containing natural gas, crude oil
and combinations of these; the natural resource may be fresh water;
it may be a heat source for geothermal energy; or it may be some
other natural resource that is located within the ground.
[0019] As used herein, unless specified others wise, the terms
"formation," "reservoir," "pay zone," and similar terms, are to be
given their broadest possible meanings and would include all
natural and man made locations, structures, geological features
within the earth, all natural and man made locations, structures,
geological features within the earth that contain natural
resources, such as hydrocarbons, water, or geothermal energy, and
all natural and man made locations, structures, geological features
within the earth that may contain or are believed to contain
natural resources, such as hydrocarbons, water, or geothermal
energy.
[0020] As used herein, unless specified otherwise, the terms
"field," "oil field" and similar terms, are to be given their
broadest possible meanings, and would include any area of land, sea
floor, water that is loosely or directly associated with a
formation, and more particularly with a resource containing
formation, thus, a field may have one or more exploratory and
producing wells associated with it, a field may have one or more
governmental body resource leases associated with it, one or more
field(s) may be directly associated with a resource containing
formation.
[0021] These resource-containing formations may be at or near the
surface, at or near the sea floor, a few hundred feet, a few
thousand feet, or tens of thousands of feet below the surface of
the earth, including under the floor of a body of water, e.g.,
below the sea floor. In addition to being at various depths within
the earth, these formations may cover areas of differing sizes,
shapes and volumes.
[0022] Unfortunately, and generally, when a well is drilled into
these formations the natural resources rarely flow into the well at
rates, durations and amounts that are economically viable. This
problem occurs for several reasons, some of which are understood,
others of which are not as well understood, and some of which may
not yet be known. These problems can relate to the viscosity of the
natural resource, the porosity of the formation, the geology of the
formation, the formation pressures, and the openings that place the
resource recovery conduit, e.g., production tubing, in the well in
fluid communication with the formation, to name a few.
[0023] Typically, and by way of general illustration, in drilling a
well an initial borehole is made into the earth or seabed and then
subsequent and smaller diameter boreholes are drilled to extend the
overall depth of the borehole. Thus, as the overall borehole gets
deeper its diameter becomes smaller; resulting in what can be
envisioned as a telescoping assembly of holes with the largest
diameter hole being at the top of the borehole closest to the
surface of the earth.
[0024] Thus, by way of example, the starting phases of a subsea
drill process may be explained in general as follows. Once the
drilling rig is positioned on the surface of the water over the
area where drilling is to take place, an initial borehole is made
by drilling a 36'' hole in the earth to a depth of about 200-300
ft. below the seafloor. A 30'' casing is inserted into this initial
borehole. This 30'' casing may also be called a conductor. The 30''
conductor may or may not be cemented into place. During this
drilling operation a riser is generally not used and the cuttings
from the borehole, e.g., the earth and other material removed from
the borehole by the drilling activity, are returned to the
seafloor. Next, a 26'' diameter borehole is drilled within the 30''
casing, extending the depth of the borehole to about 1,000-1,500
ft. This drilling operation may also be conducted without using a
riser. A 20'' casing is then inserted into the 30'' conductor and
26'' borehole. This 20'' casing is cemented into place. The 20''
casing has a wellhead secured to it. (In other operations an
additional smaller diameter borehole may be drilled, and a smaller
diameter casing inserted into that borehole with the wellhead being
secured to that smaller diameter casing.) A BOP is then secured to
a riser and lowered by the riser to the sea floor; where the BOP is
secured to the wellhead. From this point forward all drilling
activity in the borehole takes place through the riser and the
BOP.
[0025] For a land based drill process, the steps are similar,
although the large diameter tubulars, 30''-20'' are typically not
used. Thus, and generally, there is a surface casing that is
typically about 133/8'' diameter. This may extend from the surface,
e.g., wellhead and BOP, to depths of tens of feet to hundreds of
feet. One of the purposes of the surface casing is to meet
environmental concerns in protecting ground water. The surface
casing should have sufficiently large diameter to allow the drill
string, product equipment such as ESPs and circulation mud to pass
by. Below the casing one or more different diameter intermediate
casings may be used. (It is understood that sections of a borehole
may not be cased, which sections are referred to as open hole.)
These can have diameters in the range of about 9'' to about 7'',
although larger and smaller sizes may be used, and can extend to
depths of thousands and tens of thousands of feet. Inside of the
casing and extending from a pay zone, or production zone of the
borehole up to and through the wellhead on the surface is the
production tubing. There may be a single production tubing or
multiple production tubings in a single borehole, with each of the
production tubing ending at different depths.
[0026] Typically, when completing a well, it is necessary to
perform a perforation operation, and also in some instances perform
a hydraulic fracturing, or fracing operation. In general, when a
well has been drilled and casing, e.g., a metal pipe, is run to the
prescribed depth, the casing is typically cemented in place by
pumping cement down and into the annular space between the casing
and the earth. The casing, among other things, prevents the hole
from collapsing and fluids from flowing between permeable zones in
the annulus. (In some situations only the metal casing is present,
in others there may be two metal casing present one inside of the
other, there may be more that two metal casing present each inside
of the other, in still others the metal casing and cement are
present, and in others there could be other configurations of
metal, cement and metal; and in others there may be an open hole,
e.g., no casing, liner or cement is present, at the location of
interest in the borehole.) Thus, this casing forms a structural
support for the well and a barrier to the earth.
[0027] While important for the structural integrity of the well,
the casing and cement present a problem when they are in the
production zone. Thus, in addition to holding back the earth, they
also prevent the hydrocarbons from flowing into the well and from
being recovered. Additionally, the formation itself may have been
damaged by the drilling process, e.g., by the pressure from the
drilling mud, and this damaged area of the formation may form an
additional barrier to the flow of hydrocarbons into the well.
Similarly, in most situations where casing is not needed in the
production area, e.g., open hole, the formation itself is generally
tight, and more typically can be very tight and thus will not
permit the hydrocarbons to flow into the well. (In some situations
the formation pressure is large enough that the hydrocarbons
readily flow into the well in an uncased, or open hole.
Nevertheless, as formation pressure lessens a point will be reached
where the formation itself shuts-off, or significantly reduces, the
flow of hydrocarbons into the well. Also the low formation pressure
could prevent fluid from flowing from the bottom of the borehole to
the surface, requiring the use of artificial lift.)
[0028] To overcome this problem of the flow of hydrocarbons into
the well being blocked by the casing, cement and the formation
itself, openings, e.g., perforations, are made in the well in the
area of the pay zone. Generally, a perforation is a small, about
1/4'' to about 1'' or 2'' in diameter hole that extends through the
casing, cement and damaged formation and goes into the formation.
This hole creates a passage for the hydrocarbons to flow from the
formation into the well. In a typical well a large number of these
holes are made through the casing and into the formation in the pay
zone.
[0029] Generally, in a perforating operation a perforating tool or
gun is lowered into borehole to the location where the production
zone or pay zone is located.
[0030] The perforating gun is a long, typically round tool, that
has a small enough diameter to fit into the casing or tubular and
reach the area within the borehole where the production zone is
believed to be. Once positioned in the production zone a series of
explosive charges, e.g., shaped charges, are ignited. The hot gases
and molten metal from the explosion cut a hole, i.e., the perf or
perforation, through the casing and into the formation. These
explosive made perforation, may only extend a few inches, e.g., 6''
to 18'' into the formation. In hard rock formations the explosive
perforation device may only extend an inch or so, and may function
poorly, if at all. Additionally, because these perforations are
made with explosives they typically have damages areas, which
include, loose rock and perforation debris along the bottom of the
hole; and a damaged zone extending annularly around the hole.
Beyond the damaged zone is a virgin zone extending annularly around
the damage zone. The damage zone, which typically encompasses the
entire hole, generally, greatly reduces the permeability of the
formation. This has been a long standing, and unsolved problem,
among others, with the use of explosive perforations. The
perforation holes are made to get through one group of obstructions
to the flow of hydrocarbons into the well, e.g., the casing, and in
doing so they create a new group of these obstructions, e.g., the
damage area encompassing the perforation holes.
[0031] The ability, or ease, by which the natural resource can flow
out off the formation and into the well or production tubing (into
and out of, for example, in the case of engineered geothermal
wells, and some advanced recovery methods for hydrocarbon wells)
can generally be understood as the fluid communication between the
well and the formation. As this fluid communication is increased
several enhancements or benefits may be obtained: the volume or
rate of flow (e.g., gals per minute) can increase; the distance
within the formation out from the well where the natural resources
will flow into the well can be increase (e.g., the volume and area
of the formation that can be drained by a single well is increased
and it will thus take less total wells to recover the resources
from an entire field); the time period when the well is producing
resources can be lengthened; the flow rate can be maintained at a
higher rate for a longer period of time; and combinations of these
and other efficiencies and benefits.
[0032] Fluid communication between the formation and the well can
be greatly increased by the use of hydraulic fracturing techniques.
The first uses of hydraulic fracturing date back to the late 1940s
and early 1950s. In general, hydraulic fracturing treatments
involve forcing fluids down the well and into the formation, the
fluids enter the formation and crack open the rock, e.g., force the
layers of rock to break apart or fracture. These fractures create
channels or flow paths that may have cross sections of a few
millimeters, to several millimeters, to several centimeters, and
potentially larger. The fractures may also extend out from the well
in all directions for a few feet, several feet and tens of feet or
further. It should be remembered that no wellbore or branch of a
wellbore is perfectly vertical or horizontal. The longitudinal axis
of the well bore in the reservoir will most likely be on an angle
to both the vertical and the horizontal directions. The borehole
could be sloping up or down or on occasion be mostly horizontal.
The section of the well bore located within the reservoir, i.e. the
section of the formation containing the natural resources, can be
called the pay zone. For example, in the recovery of shale gas and
oil the wells are typically essentially horizontal in the
reservoir.
[0033] Generally, in a hydraulic fracturing operation a mixture of
typically a water based fluid with sand or other small particles,
e.g., proppants, is forced into the well and out into the formation
(if the well is perforated the fracturing fluid is forced out and
through one or more of the perforations and into the formation).
The fluids used to perform hydraulic fracture can range from very
simple to multicomponent formulations, e.g., water, water
containing gelling agents to increase the viscosity of the
fracturing fluid. Additionally, these fluids, e.g., fracing fluids
or fracturing fluids, typically carry with them Propping Agents
(proppants). Proppants are small particles, e.g., grains of sand or
other material, that are flowed into the fractures and hold open
the fractures when the pressure of the fracturing fluid is reduced
and the fluid is removed to allow the resource, e.g., hydrocarbons,
to flow into the well. In this manner the proppants hold open the
fractures, keeping the channels open so that the hydrocarbons can
more readily flow into the well. Additionally, the fractures
greatly increase the surface area from which the hydrocarbons can
flow into the well. Proppants may not be needed, or generally may
not be used when acids are used to create a frac and subsequent
channel in a carbonate rich reservoir where the acids dissolve part
or all of the rock leaving an opening for the formation fluids to
flow to the wellbore.
[0034] Typical fluid volumes in a propped fracturing treatment of a
formation in general can range from a few thousand to a few million
gallons. Proppant volumes can be several thousand cubic feet, and
can approach several hundred thousand cubic feet. For example, for
a single well 3-5 million gallons of water may be used and
pressures may be in the range of about 500 psi and greater, at
least about 1,000 psi, about 5,000 psi to about 10,000 psi, as high
as 15,000 psi and potentially higher. As the fracturing fluid and
proppants are forced into the formation at high injection rate, the
bottom hole pressure increases enough to overcome the stresses and
the rock tensile strength so that the formations breaks or
fractures. Sometimes the breaks occur along planes of weakness that
are called joints. Naturally occurring joints in the formation may
also be opened, expanded and propagated by the fluid. In order to
keep these newly formed and enlarged fractures, cracks or joints
open, once the pressure and fluid are removed, the proppants are
left behind. They in essence hold open, i.e., "prop" open, the
newly formed and enlarged fractures, cracks, or joints in the
formation.
[0035] Additionally, hydraulic fracturing has come under public and
consequentially regulatory scrutiny for environmental reasons. This
scrutiny has looked to such factors as: the large amounts of water
used; the large amounts of vehicles, roads and other infrastructure
needed to perform a fracturing operation; potential risks to ground
water; potential risks of seismic activities; and potential risks
from additives to the water, among other things.
SUMMARY
[0036] In the acquisition of natural sources, such as oil and
natural gas, there exists a long felt need to have safe,
controllable and predictable ways to establish and enhance fluid
communication between the resource containing formation and the
well bore. Incremental improvements in explosive perforating guns,
and other conventional techniques have not met these long felt
needs. It is the present inventions, among other things, that solve
these needs by providing the articles of manufacture, devices and
processes taught herein.
[0037] Thus, there is provided a method of producing hydrocarbons
from a formation, the method having the operations of: identifying
a stress in the formation in an area of the formation adjacent to a
location along a borehole; positioning a laser perforating tool in
the borehole at the location; determining the position of a laser
beam path, the laser beam path position based at least in part upon
the stress in the formation; delivering a high power laser beam
having at least about 5 kW of power along a laser beam path,
whereby the laser beam creates a laser perforation; and, flowing a
fracturing fluid under pressure down the borehole, through the
laser perforation and into the formation, whereby the formation is
hydraulically fractured with minimal near bore hole tortuosity.
[0038] There is further provided stimulation methods, perforation
methods, production of hydrocarbon methods, or fracturing methods
in which one or more of the following also may be present: wherein
the location along the borehole is at about 5,000 feet or more
measured depth and the laser beam has a power of at least about 10
kW; wherein the location along the borehole is at about 10,000 feet
or more measured depth depth and the laser beam has a power of at
least about 10 kW; wherein the location along the borehole is at
about 5,000 feet or more measured depth and the laser beam has a
power of at least about 15 kW; wherein the location along the
borehole is at about 10,000 feet or more measured depth depth and
the laser beam has a power of at least about 15 kW; wherein the
identification of stress in the formation including using laser
adaptive fracturing; wherein the laser adaptive fracturing
including creating a first laser perforation, performing a
mini-fracture through the laser perforation, and evaluating the
mini-fracture to identify a formation condition; wherein the acts
of perforating and mini-fracturing are repeated, and the formation
condition is a preferred stress plane for the formation; wherein
the laser beam path follows the preferred stress plane; wherein the
laser beam path is positioned in the preferred stress plane;
wherein the laser beam path is positioned in and parallel with the
preferred stress plane; wherein the identified stress including a
preferred stress plane and the laser beam path follows the
preferred stress plane; wherein the identified stress including a
preferred stress plane and the laser beam path is positioned in the
preferred stress plane; wherein the identification of stress in the
formation including using laser adaptive fracturing; wherein the
laser adaptive fracturing including creating a first laser
perforation, performing a mini-fracture through the laser
perforation, and evaluating the mini-fracture to identify a
formation condition; wherein the laser perforating tool including a
tractor section, and a laser cutting head section; wherein the
laser perforating tool including a tractor section, and a laser
cutting head section; wherein the laser perforating tool including
a tractor section, a laser cutting head section, and a means to
axially extend the laser cutting head section; and the means to
axially extend the laser cutting section including a motor a
controller and an advancement screw; and, wherein the laser
perforating tool is located within a laser hydraulic fracturing
apparatus, the laser hydraulic fracturing apparatus having a packer
assembly.
[0039] Additionally, there is provided a method of stimulating a
well, including: positioning a laser perforating tool in the
borehole at a location in a formation; delivering a plurality of
high power laser beams, each having at least about 10 kW of power,
in a plurality of predetermined laser beam patterns; the laser beam
patterns position at the location and extending along a length of
the borehole, wherein the position of the laser beam patterns is
based at least in part upon a stress plane in the formation;
whereby each laser beam creates a discrete volumetric removal
having a predetermined shape defining a laser perforation; and,
flowing a fracturing fluid under pressure down the borehole,
through the laser perforation and into the formation, whereby the
formation is hydraulically fractured.
[0040] Yet further there is provided stimulation methods,
perforation methods, production of hydrocarbon methods, or
fracturing methods in which one or more of the following also may
be present: wherein the shape of the laser beam patterns is
predetermined at least in part to reduce near borehole tortuosity;
wherein the position of the laser beam patterns is based at least
in part to reduce near borehole tortuosity; wherein the shape of
the laser beam patterns is predetermined at least in part to reduce
near borehole tortuosity and the position of the laser beam
patterns is based at least in part to reduce near well bore
tortuosity; wherein the shape of the laser beam patterns is at
least in part reduces near borehole tortuosity; wherein the
position of the laser beam patterns at least in part reduces near
borehole tortuosity; wherein the shape of the laser beam patterns
is at least in part essentially eliminates near borehole
tortuosity; wherein the position of the laser beam patterns at
least in part essentially eliminates near borehole tortuosity;
wherein the shape of the laser beam patterns is at least in part
essentially eliminates the adverse flow characteristics associated
with near borehole tortuosity; wherein the position of the laser
beam patterns at least in part essentially eliminates the adverse
flow characteristics associated with near borehole tortuosity;
wherein the shape of the laser beam patterns is predetermined at
least in part to reduce near borehole tortuosity and the position
of the laser beam patterns is based at least in part to reduce near
well bore tortuosity; wherein the location along the borehole is at
about 5,000 feet or more measured depth and the laser beam has a
power of at least about 10 kW; wherein the location along the
borehole is at about 10,000 feet or more measured depth depth and
the laser beam has a power of at least about 10 kW; wherein the
location along the borehole is at about 5,000 feet or more measured
depth and the laser beam has a power of at least about 15 kW;
wherein the location along the borehole is at about 10,000 feet or
more measured depth depth and the laser beam has a power of at
least about 15 kW; wherein the location along the borehole is at
about 5,000 feet or more measured depth and the laser beam has a
power of at least about 10 kW; wherein the location along the
borehole is at about 5,000 feet or more measured depth depth and
the laser beam has a power of at least about 10 kW; wherein the
laser perforating tool including a tractor section, and a laser
cutting head section; wherein the laser perforating tool including
a tractor section, a laser cutting head section, and a means to
axially extend the laser cutting head section; wherein the laser
perforating tool including a tractor section, a laser cutting head
section, and a means to axially extend the laser cutting head
section; and the means to axially extend the laser cutting section
including a motor a controller and an advancement screw; wherein
the laser perforating tool including a tractor section, a laser
cutting head section, and a means to axially extend the laser
cutting head section; wherein the laser perforating tool is located
within a laser hydraulic fracturing apparatus, the laser hydraulic
fracturing apparatus having a packer assembly; and, wherein the
laser perforating tool is located within a laser hydraulic
fracturing apparatus, and the laser hydraulic fracturing apparatus
having a packer assembly.
[0041] Additionally, there is provided a method of hydraulically
fracturing a well, which method includes the activities of:
positioning a laser hydraulic fracturing assembly in the borehole
at a location in a formation; delivering a plurality of high power
laser beams, each having at least about 10 kW of power, in a
plurality of predetermined laser beam patterns; the laser beam
patterns positioned at the location and extending along a length of
the borehole, wherein the position of the laser beam patterns is
based at least in part upon a stress plane in the formation;
whereby each laser beam creates a discrete volumetric removal
having a predetermined shape defining a laser perforation; and,
flowing a fracturing fluid under pressure down the borehole,
through the laser perforation and into the formation, whereby the
formation is hydraulically fractured.
[0042] Moreover, there is provided stimulation methods, perforation
methods, production of hydrocarbon methods, or fracturing methods
in which one or more of the following also may be present: wherein
the shape of the laser beam patterns is predetermined at least in
part to reduce near borehole tortuosity; wherein the position of
the laser beam patterns is based at least in part to reduce near
borehole tortuosity; and wherein the location along the borehole is
at about 5,000 feet or more measured depth and the laser beam has a
power of at least about 10 kW; wherein the shape of the laser beam
patterns is predetermined at least in part to reduce near borehole
tortuosity and the position of the laser beam patterns is based at
least in part to reduce near well bore tortuosity; wherein the
shape of the laser beam patterns at least in part reduces near
borehole tortuosity; and wherein the location along the borehole is
at about 5,000 feet or more measured depth and the laser beam has a
power of at least about 10 kW; wherein the shape of the laser beam
patterns at least in part essentially eliminates near borehole
tortuosity; wherein the position of the laser beam patterns at
least in part essentially eliminates near borehole tortuosity; and
wherein the location along the borehole is at about 5,000 feet or
more measured depth and the laser beam has a power of at least
about 10 kW; and, wherein the shape of the laser beam patterns at
least in part essentially eliminates the adverse flow
characteristics associated with near borehole tortuosity.
[0043] Still additionally, there is provided a method of
stimulating a well, including: positioning a laser beam delivery
head in the borehole at a location in a formation, the location
being at a measured depth of at least 5,000 ft; delivering a
plurality of high power laser beams, each having at least about 10
kW of power, in a plurality of predetermined laser beam patterns;
the laser beam patterns positioned at the location and extending
along a length of the borehole, wherein the position of the laser
beam patterns is based at least in part upon a stress plane in the
formation; whereby each laser beam creates a discrete volumetric
removal having a predetermined shape defining a laser perforation;
and, flowing a fracturing fluid under pressure down the borehole,
through the laser perforation and into the formation, whereby the
formation is hydraulically fractured.
[0044] Moreover, there is provided stimulation methods, perforation
methods, production of hydrocarbon methods, or fracturing methods
in which one or more of the following also may be present: wherein
the stress plane is a preferred stress plane; wherein the
identified stress including a preferred stress plane and at least
one volumetric removal follows the preferred stress plane; wherein
the identified stress including a preferred stress plane and the
volumetric removals follow the preferred stress plane; wherein the
identified stress including a preferred stress plane and at least
one volumetric removal is positioned in and parallel with the
preferred stress plane; having identifying the stress in the
formation using laser adaptive fracturing; and, wherein at least
one volumetric removal follows the stress plane; wherein the
volumetric removals follow the stress plane; wherein at least one
volumetric removal is positioned in and parallel with the preferred
stress plane; wherein the volumetric removals are positioned in and
parallel with the stress plane; wherein the fracturing fluid is
slick water; wherein the fracturing fluid including a proppant;
wherein the proppant is a sand; wherein the location in the
borehole is substantially vertical; wherein the location in the
borehole is substantially horizontal; wherein the borehole has a
TVD of at least about 5,000 ft, a MD of at least about 15,000, and
a substantially horizontal section having a length of at least
about 5,000 ft; wherein the borehole has a TVD of at least about
5,000 ft, a MD of at least about 15,000, and a substantially
horizontal section having a length of at least about 5,000 ft;
wherein the borehole has a TVD of at least about 5,000 ft, a MD of
at least about 15,000, and a substantially horizontal section
having a length of at least about 5,000 ft; wherein the volumetric
removals are in the shape of a disc, each having a volume removed
of greater than about 1 cubic inches; wherein at least one
volumetric removal is in the shape of a disc having a volume
removed of greater than about 1 cubic inches; wherein at least one
volumetric removal is in the shape of a disc having a volume
removed of greater than about 1 cubic inches; wherein at least one
volumetric removal is in the shape of a disc having a volume
removed of greater than about 1 cubic inches; wherein at least one
volumetric removal is in the shape of a disc having a volume
removed of greater than about 1 cubic inches; wherein at least one
volumetric removal is in the shape of a disc having a volume
removed of greater than about 7 cubic inches; wherein the
volumetric removals are in the shape of a disc, each disc having a
volume removed of greater than about 7 cubic inches; wherein for
each volumetric removal the volume removed is greater than about 7
cubic inches; wherein for each volumetric removal the volume
removed is greater than about 50 cubic inches; wherein the
volumetric removal is in the shape of a disc having a volume
removed of greater than about 7 cubic inches; wherein the
volumetric removal is in the shape of a disc having a volume
removed of greater than about 50 cubic inches; wherein the
volumetric removal is in the shape of a disc having a volume
removed of greater than about 100 cubic inches; wherein the
plurality of volumetric removals including at least four discrete
shapes; wherein the plurality of volumetric removals including at
least five discrete shapes; wherein the plurality of volumetric
removals including at least six discrete shapes; wherein the
plurality of volumetric removals including at least four discrete
shapes; wherein the plurality of volumetric removals including at
least five discrete shapes; wherein the plurality of volumetric
removals including at least four discrete shapes; and wherein the
removed volume for each discrete shape is at least 7 cubic inches;
wherein the plurality of volumetric removals including at least
five discrete shapes; and wherein the removed volume for each
discrete shape is at least 7 cubic inches; wherein the plurality of
volumetric removals including at least six discrete shapes; and
wherein the removed volume for each discrete shape is at least 7
cubic inches; wherein the plurality of volumetric removals
including at least four discrete shapes; and wherein the removed
volume for each discrete shape is at least 50 cubic inches; wherein
the plurality of volumetric removals including at least five
discrete shapes; and wherein the removed volume for each discrete
shape is at least 50 cubic inches; wherein the plurality of
volumetric removals including at least six discrete shapes; and
wherein the removed volume for each discrete shape is at least 50
cubic inches; wherein the volumetric removals are each in the shape
of a rectangular slot; wherein at least one volumetric removal is
in the shape of a rectangular slot having a volume removed of
greater than about 100 cubic inches; wherein at least one
volumetric removal is in the shape of a rectangular slot having a
volume removed of greater than about 150 cubic inches; wherein at
least one volumetric removal is in the shape of a rectangular slot
having a volume removed of greater than about 100 cubic inches;
and, wherein at least one volumetric removal is in the shape of a
rectangular slot having a volume removed of greater than about 150
cubic inches.
[0045] Moreover there is provided a method of producing
hydrocarbons from a formation, including: identifying stresses in
the formation in an area of the formation adjacent to a location
along a borehole; positioning a laser perforating tool in the
borehole at the location; delivering a high power laser beam having
at least about 5 kW of power in a predetermined laser beam pattern,
the laser beam pattern position based at least in part upon the
stresses in the formation; whereby the laser beam volumetrically
removes a material in the shape of the laser beam pattern creating
a laser perforation; and, flowing a fracturing fluid under pressure
down the borehole, through the laser perforation and into the
formation, whereby the formation is hydraulically fractured.
[0046] Furthermore, there is provided stimulation methods,
perforation methods, production of hydrocarbon methods, or
fracturing methods in which one or more of the following also may
be present: wherein the material removed consists of the formation;
wherein the material removed consists of the formation; wherein the
material removed includes a coiled tubing; wherein the material
removed includes a casing and the formation; wherein the material
removed is a casing; wherein the material removed is a first
tubular and a second tubular surrounding the first tubular; wherein
the material removed is a casing; wherein the material removed is a
first tubular and a second tubular surrounding the first tubular
and the formation; wherein the material removed includes a casing,
a cement, and the formation; wherein the laser adaptive fracturing
including creating a first laser perforation, performing a
mini-fracture through the laser perforation, and evaluating the
mini-fracture to identify a formation condition; and, wherein the
laser adaptive fracturing including creating a first laser
perforation, performing a mini-fracture through the laser
perforation, and evaluating the mini-fracture to identify a
formation condition; wherein the identified stress including a
preferred stress plane and the laser beam pattern follows the
preferred stress plane.
[0047] Yet moreover there is provided a method of laser hydraulic
fracturing a well, the method having the steps of: positioning a
laser perforating tool in the borehole at a location in a
formation; delivering a plurality of high power laser beams each
having at least about 10 kW of power in a plurality of
predetermined laser beam patterns, the laser beam patterns position
at the location and extending along a length of the borehole,
wherein the position of the laser beam patterns is based at least
in part upon a stress plane in the formation; whereby each laser
beam creates a discrete volumetric removal having a predetermined
shape defining a laser perforation; and, flowing a fracturing fluid
under pressure down the borehole, through the laser perforation and
into the formation, whereby the formation is hydraulically
fractured.
[0048] Still further, there is provided stimulation methods,
perforation methods, production of hydrocarbon methods, or
fracturing methods in which one or more of the following also may
be present: wherein each laser perforation defines an opening in a
casing in the borehole, wherein each opening is a circle, and
wherein the diameters of each opening vary by no more than about
2%; wherein each laser perforation defines an opening in a casing
in the borehole having an opening edge, wherein each opening is a
circle, and wherein each opening edge is essentially burr free;
wherein each laser perforation defines an opening in a casing in
the borehole having an opening edge, wherein each opening is a
circle, and wherein each opening edge is essentially smooth; and
wherein near borehole tortuosity is essentially not present;
wherein near borehole tortuosity is not present.
[0049] Additionally there is provided a method of drilling a well
in a shale reservoir, including: advancing a bore hole to and into
a shale reservoir, the borehole having an essentially vertical
component and and essentially horizontal component, the borehole
having a TVD of greater than 1,000 feet and a MD of greater than
about 5,000 ft, deploying a laser hydraulic fracturing apparatus in
the borehole; cutting a laser perforation pattern into the
formation; activating a first packer and a second packer, whereby
the packers define a first stage, hydraulically fracturing the
first stage.
[0050] Still further there is provided a method of drilling wherein
the laser hydraulic fracturing apparatus includes a laser
perforating tool, and wherein the laser perforating tool in part
defines a seal for the fracturing stage.
[0051] Yet further, there is provided a method wherein the laser
hydraulic fracturing apparatus including a laser perforating tool,
and the laser perforating tool remains in the horizontal section of
the borehole during the hydraulic fracturing.
[0052] Still further there is provided a method of drilling a well
in a reservoir, including: advancing a bore hole to and into a
reservoir, the borehole having an essentially vertical component
and and essentially horizontal component, the borehole having a TVD
of greater than 1,000 feet and a MD of greater than about 5,000 ft,
deploying a laser hydraulic fracturing apparatus in the borehole,
the apparatus having a plurality of means for sealing against an
inner wall of the borehole, a laser perforating tool, a high power
laser conveyance structure, a means for axially advancing a laser
cutter, and a means for sealing against the laser perforating tool
or the laser conveyance structure; cutting a laser perforation
pattern into the formation; sealing the borehole below the laser
perforation and hydraulically fracturing the formation.
[0053] Yet further, there is provided a laser hydraulic fracturing
assembly, the assembly having: a connector for connecting to a
tubular; a first and a second, outwardly sealing, sealing
assemblies; a laser perforating tool, having a sealing section, the
sealing section having a high power laser conveyance structure;
and, an inwardly sealing, sealing assembly, whereby the inwardly
sealing assembly is capable of forming a seal with the sealing
section that is capable of withstanding the pressure and flow of
hydraulic fracturing.
[0054] There is provided a method of producing hydrocarbons from a
formation, the method having the operations of: identifying a
stress in the formation in an area of the formation adjacent to a
location along a borehole; positioning a laser perforating tool in
the borehole at the location; determining the position of a laser
beam path, the laser beam path position based at least in part upon
the stress in the formation; delivering a high power laser beam
having at least about 5 kW of power along a laser beam path,
whereby the laser beam creates a laser perforation.
[0055] Additionally, there is provided a method of stimulating a
well, including: positioning a laser perforating tool in the
borehole at a location in a formation; delivering a plurality of
high power laser beams, each having at least about 10 kW of power,
in a plurality of predetermined laser beam patterns; the laser beam
patterns position at the location and extending along a length of
the borehole, wherein the position of the laser beam patterns is
based at least in part upon a stress plane in the formation; and,
whereby each laser beam creates a discrete volumetric removal
having a predetermined shape defining a laser perforation.
[0056] Additionally, there is provided a method of producing
hydrocarbons, which method includes the activities of: positioning
a laser hydraulic fracturing assembly in the borehole at a location
in a formation; delivering a plurality of high power laser beams,
each having at least about 10 kW of power, in a plurality of
predetermined laser beam patterns; the laser beam patterns
positioned at the location and extending along a length of the
borehole, wherein the position of the laser beam patterns is based
at least in part upon a stress plane in the formation; and, whereby
each laser beam creates a discrete volumetric removal having a
predetermined shape defining a laser perforation.
[0057] Still additionally, there is provided a method of
stimulating a well, including: positioning a laser beam delivery
head in the borehole at a location in a formation, the location
being at a measured depth of at least 5,000 ft; delivering a
plurality of high power laser beams, each having at least about 10
kW of power, in a plurality of predetermined laser beam patterns;
the laser beam patterns positioned at the location and extending
along a length of the borehole, wherein the position of the laser
beam patterns is based at least in part upon a stress plane in the
formation; and, whereby each laser beam creates a discrete
volumetric removal having a predetermined shape defining a laser
perforation.
[0058] Moreover there is provided a method of producing
hydrocarbons from a formation, including: identifying stresses in
the formation in an area of the formation adjacent to a location
along a borehole; positioning a laser perforating tool in the
borehole at the location; delivering a high power laser beam having
at least about 5 kW of power in a predetermined laser beam pattern,
the laser beam pattern position based at least in part upon the
stresses in the formation; and, whereby the laser beam
volumetrically removes a material in the shape of the laser beam
pattern creating a laser perforation.
[0059] Yet moreover, there is provided a method of stimulation
including: positioning a laser perforating tool in the borehole at
a location in a formation; delivering a plurality of high power
laser beams each having at least about 10 kW of power in a
plurality of predetermined laser beam patterns, the laser beam
patterns position at the location and extending along a length of
the borehole, wherein the position of the laser beam patterns is
based at least in part upon a stress plane in the formation; and,
whereby each laser beam creates a discrete volumetric removal
having a predetermined shape defining a laser perforation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 is a schematic perspective view of an embodiment of a
laser hydraulic fracturing field site in accordance with the
present inventions.
[0061] FIG. 2 is a perspective view of an embodiment of laser
system providing an embodiment of a laser energy delivery pattern
in accordance with the present inventions.
[0062] FIG. 3 is a perspective view of an embodiment of a laser
energy delivery pattern in accordance with the present
inventions.
[0063] FIG. 4 is a perspective view of an embodiment of a laser
energy delivery pattern in accordance with the present
inventions.
[0064] FIG. 5A is a perspective view of an embodiment of a laser
energy delivery pattern in accordance with the present
inventions.
[0065] FIG. 5B is a perspective view of an embodiment of a laser
energy delivery pattern in accordance with the present
inventions.
[0066] FIG. 6 is schematic view of an embodiment of a laser energy
delivery pattern in accordance with the present inventions.
[0067] FIGS. 7A and 7B are plan and perspective views respectively
of an embodiment of a laser energy delivery pattern in accordance
with the present inventions.
[0068] FIGS. 8A and 8B are plan and perspective views respectively
of an embodiment of a laser energy delivery pattern in accordance
with the present inventions.
[0069] FIGS. 9A and 9B are plan and perspective views respectively
of an embodiment of a laser energy delivery pattern in accordance
with the present inventions.
[0070] FIG. 10 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0071] FIG. 11 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0072] FIG. 12 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0073] FIG. 13 is a perspective view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0074] FIG. 13A is a cutaway perspective view of an embodiment of a
laser perforating head in accordance with the present
inventions.
[0075] FIG. 14A is a perspective view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0076] FIG. 14B is a cutaway perspective view of the embodiment of
FIG. 14A.
[0077] FIG. 14C is a cutaway perspective view of a component of the
embodiment of FIG. 14A.
[0078] FIGS. 15A and 15B are cross sectional views of an embodiment
of a laser perforation tool in accordance with the present
inventions.
[0079] FIG. 16 is a perspective view of an embodiment of a laser
perforating head in accordance with the present inventions.
[0080] FIG. 16A is a perspective view of the optic assembly of the
embodiment of FIG. 16.
[0081] FIG. 16B is a cross section view of a laser beam launch
member of the optic assembly of the embodiment of FIG. 16A.
[0082] FIG. 17 is a perspective view of an embodiment of a laser
fracturing adapter in accordance with the present inventions.
[0083] FIG. 18 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0084] FIG. 19 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0085] FIG. 20 is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0086] FIG. 21 is perspective view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0087] FIG. 21A is cross sectional view of the embodiment of FIG.
16 as taken along line A-A of FIG. 16.
[0088] FIG. 22A is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0089] FIG. 22B is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0090] FIG. 23A is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0091] FIG. 23B is schematic view of an embodiment of a laser
perforating tool in accordance with the present inventions.
[0092] FIG. 24A is a perspective view of an embodiment of an optics
assembly in accordance with the present inventions.
[0093] FIG. 24B is a cross sectional view of the embodiment of FIG.
24A.
[0094] FIG. 24C is a cross sectional view of the embodiment of FIG.
24A.
[0095] FIG. 24D is a cross sectional view of the embodiment of FIG.
24A.
[0096] FIG. 25 is a schematic of an embodiment of an optical
configuration in accordance with the present inventions.
[0097] FIG. 26A is a schematic side view of an embodiment of an
optical configuration in accordance with the present
inventions.
[0098] FIG. 26B is a schematic plan view of the embodiment of FIG.
26A.
[0099] FIG. 27 is a schematic of an embodiment of a laser beam
profile in accordance with the present inventions.
[0100] FIGS. 28A, 28B and 28C are schematic snap shots of an
embodiment of a process in accordance with the present
inventions.
[0101] FIG. 29 is a schematic representation of an embodiment of a
process in accordance with the present inventions.
[0102] FIGS. 30A, 30B and 30C are snap shots of an embodiment of a
laser perforating tool in operation in accordance with the present
inventions.
[0103] FIGS. 30D to 30F are prespective views of components of the
laser perforation tool of FIGS. 30A to 30C.
[0104] FIG. 31 is a schematic perspective view of an embodiment of
a casing in a formation for laser perforating and fracturing in
accordance with the present inventions.
[0105] FIG. 32 is a schematic perspective view of an embodiment of
a casing in a formation for laser perforating and fracturing in
accordance with the present inventions.
[0106] FIG. 33 is a schematic view of an embodiment of a borehole
path in a formation for laser perforating and fracturing in
accordance with the present inventions.
[0107] FIG. 34 is a cross sectional view of an embodiment of a
laser hydraulic fracturing assembly in accordance with the present
inventions.
[0108] FIG. 34A is an enlarged cross sectional view of the packer
assembly of the embodiment of FIG. 34 expanded in accordance with
the present inventions.
[0109] FIG. 35 is a perspective cross sectional view of an
embodiment of laser perforations in accordance with the present
inventions.
[0110] FIG. 36 is a perspective cross sectional view of an
embodiment of laser perforations in accordance with the present
inventions.
[0111] FIG. 37 is a perspective cross sectional view of an
embodiment of laser perforations in accordance with the present
inventions.
[0112] FIG. 38A is axial planer view of an embodiment of a laser
perforating geometry following a stress plane of a formation in
accordance with the present inventions.
[0113] FIG. 38B is a cross sectional view of the laser perforating
geometry of FIG. 38A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0114] In general, the present inventions relate to systems,
methods and tools to establish and enhance fluid communication
between a natural resource containing formation and a well bore. In
particular, the present inventions relate to hydraulic fracturing
using high power lasers, high power laser tools, laser perforating,
laser fracturing, and laser opening, increasing and enhancing the
flow of natural resources, such as hydrocarbons and geothermal,
from a formation into a production tubing or collection system. The
present inventions, among other things, provide improved
performance, efficiency and safety over conventional explosive
based perforating guns and high pressure jetting with solids laden
fluids, as well as, provide for the precise and predetermined
placement of laser beam energy, in precise and predetermined energy
distribution patterns. These patterns can be tailored and
customized to, for example, the particular geological and
structural features of a formation and pay zone, the response of
the pay zone to fracturing, and other customized and adaptive
hydraulic fracturing and stimulation implementations. Thus, giving
rise, among other things, to never before seen, or obtainable
customization of perforating and fracturing patterns and activities
to precisely match the formation and geologic conditions.
[0115] Generally, once a borehole has been drilled to the desired
depth and position in a formation a laser field unit is positioned
near the well head. The laser field unit may have already been
present at the field for laser drilling, laser pipe cutting or
other laser oil field related operations. Further, the laser field
unit may be close or further removed from the well head, depending
upon the specific logistical constrains and considerations of the
well site, as the high power laser energy can be transmitted over
long distances. Although this specification focuses on hydrocarbon
recovery, e.g., oil and natural gas, this focus is illustrative and
it should be understood that the present inventions and their
utilization have broader applications and uses. The high power
laser field unit has a high power laser that provides a high power
laser beam, e.g., 5 kW, 10 kW, 20 kW or more. The laser is in
optical communication with a high power laser conveyance structure,
which transmits the laser beam from the laser down the borehole to
the location in the well where the laser hydraulic fracturing
process is to occur. The high power laser beam is delivered to the
borehole surface to remove material from the surface, the formation
and both. Thus, the laser beam creates an opening in the borehole
surface and into the formation. The laser beam delivery device can
then be moved in the borehole, or taken out of the borehole
entirely, as the laser cut area is isolated and the fracturing
fluid is pumped into the well and into the laser made opening to
fracture the formation.
[0116] In general, the laser beam has the ability to be shaped and
delivered in predetermined and preselected patterns, having
predetermined energy distributions, including, lines, slots, holes,
and other shapes that create volumetric removals. The laser beams
also have the ability to provide custom shaped openings, such as,
smooth edges (e.g., bur-free), bevels, tapers, curves, lips, etc.,
that, for example, will provide for better control of proppants
through casing into the formation, the building of a better
proppant pack, the ease of moving packers and other down hole
equipment into and out of the well bore, and other well operation,
completion, and fracturing fluid flow enhancements. These
volumetric removals can be customized for a particular formation,
completion strategy, other factors and considerations, and
combinations and variations of these.
[0117] Further, the laser beam delivery patterns and their
resultant volumetric removals can be adapted during the hydraulic
fracturing process. Thus, the laser beam delivery pattern can be
shaped and predetermined, while the delivery tool is down hole or
above ground, and in response to down hole information, such as for
example in response to pressure data and flow data obtained during
a fracturing stage. In this manner, the laser hydraulic fracturing
process can be customized during the fracturing stages, by cutting
new, different, or adapted openings to enhance a subsequent stage
in a fracturing operation, correct a less than optimal result from
an earlier fracturing stage, and combinations and variations of
these.
[0118] Further, the laser beam and the volumetric removal patterns
can be customized, or predetermined, to perform operations such as
correction of fracture jobs, reentry and other recompletion, or
activities for increase the production of a failing or failed well.
The laser beam may additionally be used to seal openings, such as
perforations in or damaged sections of casing, which could then
enable the fracing of a different zone or area of the well. The
laser's ability to seal and the remove material from the borehole
in a selected and predetermined manner, as well as in a repeating
manner, provides the capabilities to address many and varied
production and completion related problems and difficulties, such
as for example if a zone is producing water and/or gas.
[0119] Turning to FIG. 1 there is provided a perspective view of an
embodiment of a laser hydraulic fracturing site 1. Thus, positioned
near the well head 14 there is a laser field unit 2, pumping trucks
6, proppant storage containers 10, 11, a proppant feeder assembly
9, a blender, (e.g., mixing truck) 8, and fracturing fluid holding
units 12. As will be understood by one of skill in the hydraulic
fracturing arts, FIG. 1 is an illustration and simplification of a
fracturing site. Such sites may have more, different, and other
pieces of equipment such as pumps, holding tanks, mixers, and
chemical holding units, mixing and addition equipment, lines,
valves and transferring equipment, as well as control and
monitoring equipment.
[0120] The laser field unit has a high power laser conveyance
structure or laser umbilical 3, which enters the well head 14
through laser fracturing adapter 4. The laser fracturing adapter 4
has a high pressure line 5 that transfers high pressure fracturing
fluid from the pump trucks 6 into the well. The laser fracturing
adapter 4 has packers or other pressure managing apparatus, known
to those of skill in the art, to enable the insertion and removal
of a laser fracturing sub, a laser fracturing tool, a laser
perforating tool and the movement of the laser umbilical into and
out of the well. The well head 4 may also have further well control
devices associated with it, such as a BOP.
[0121] Fracturing fluid from holding units 12 is transferred
through lines 13 to mixing truck 8, where proppant from storage
containers 10, 11 is feed by assembly 9 and mixed with the
fracturing fluid. The fracturing fluid and proppant mixture is the
transferred to the pump trucks 6, by line 7.
[0122] In this manner the laser perforating and cutting
applications can take place, the well can be appropriately
isolated, e.g., a fracture stage, zone or predetermined section,
and the fracturing fluid can be pumped into the well under pressure
to fracture the formation.
[0123] An embodiment of a high power laser system and its
deployment and use in the field, to provide a custom laser
perforation and fracturing pattern to a formation, is shown in FIG.
2. Thus, there is provided a laser field unit, such as the
embodiment of a mobile laser conveyance truck (MLCT) 2700. The MLCT
2700 has a laser cabin 2701 and a handling apparatus cabin 2703,
which is adjacent the laser cabin. The laser cabin 2701 and the
handling cabin 2703 are located on a truck chassis 2704. In this
embodiment the delivery tool could be any of the laser delivery
tools of the embodiments in this specification.
[0124] The laser cabin 2701 houses a high power fiber laser 2702,
(e.g., 20 kW; wavelength of 1070-1080 nm); a chiller assembly 2706,
which has an air management system 2707 to vent air to the outside
of the laser cabin and to bring fresh air in to the chiller (not
shown in the drawing). The laser cabin also has two holding tanks
2708, 2709. These tanks are used to hold fluids needed for the
operation of the laser and the chiller during down time and
transit. The tanks have heating units to control the temperature of
the tank and in particular to prevent the contents from freezing,
if power or the heating and cooling system for the laser cabin was
not operating. A control system 2710 for the laser and related
components is provided in the laser cabin 2703. A partition 2711
separates the interior of the laser cabin from the operator booth
2712.
[0125] The operator booth contains a control panel and control
system 2713 for operating the laser, the handling apparatus, and
other components of the system.
[0126] The operator booth 2712 is separated from the handling
apparatus cabin 2703 by partition 2714.
[0127] The handling apparatus cabin 2703 contains a spool 2715
(e.g., about 6 ft OD, barrel or axle OD of about 3 feet, and a
width of about 6 feet) holding about 10,000 feet of the conveyance
structure 2717. The spool 2715 has a motor drive assembly 2716 that
rotates the spool. The spool has a holding tank 2718 for fluids
that may be used with a laser tool or otherwise pumped through the
conveyance structure and has a valve assembly for receiving high
pressure gas or liquids for flowing through the conveyance
structure.
[0128] The laser 2702 is optically associated with the conveyance
structure 2717 on the spool 2715 by way of an optical fiber and
optical slip ring (not shown in the figures). The fluid tank 2718
and the valve assembly 2719 are in fluid communication with the
conveyance structure 2717 on the spool 2715 by way of a rotary slip
ring (not shown).
[0129] The laser cabin 2701 and handling apparatus cabin 2703 have
access doors or panels (not shown in the figures) for access to the
components and equipment, to for example permit repair, replacement
and servicing. At the back of the handling apparatus cabin 2703
there are door(s) (not shown in the figure) that open during
deployment for the conveyance structure to be taken off the spool.
The MLCT 2700 has an electrical generator 2721 to provide
electrical power to the system.
[0130] The MLCT 2700 is on the surface 1100 of the earth 1102,
positioned near a wellhead 2750 of a borehole 1003, and having a
Christmas tree 2751, a BOP 2752 and a lubricator 2705. The
conveyance structure 2717 travels through winder 2720 (.e.g., line
guide, level wind) to a first sheave 2753, to a second sheave 2754,
which has a weight sensor 2755 associated with it. Sheaves 2753,
2754 make up an optical block, which is a combination of sheaves to
provide for a path, or configuration of the conveyance structure,
and also to permit the movement of the conveyance in and out of the
borehole, while not significantly interfering with, or otherwise
significantly adversely affecting the transmission of the high
power laser beam. The weight sensor 2755 may be associated with
sheave 2753 or the conveyance structure 2717. The conveyance
structure 2717 enters into the top of the lubricator and is
advanced through the BOP 2752, tree 2751 and wellhead 2750 into the
borehole 1003 below the surface of the earth 1100. The sheaves
2753, 2754 have a diameter of about 3 feet. In this deployment path
for the conveyance structure the conveyance structure passes
through several radii of curvature, e.g., the spool and the first
and second sheaves. These radii are all equal to or large than the
minimum bend radius of the high power optical fiber in the
conveyance structure. Thus, the conveyance structure deployment
path would not exceed (i.e., have a bend that is tighter than the
minimum radius of curvature) the minimum bend radius of the
fiber.
[0131] As seen in the embodiment of FIG. 2, the MLCT 2700 is
positioned over a formation 1002, in the earth 1102. The formation
1002 is shown as being freestanding, e.g., a block of material, for
the purpose of clarity in the figure. It being understood that the
formation may be deep within the earth, nearer to the surface such
as in some shale gas fields and that the orientation of borehole
1003 may be from vertical, to the essentially horizontal shown in
FIG. 2, to up turned, as well as branched.
[0132] In FIG. 2, the piping, pumps etc., for the delivery of the
fracturing fluid are not shown. Once the laser beam(s) have been
delivered the the conveyance structure and the delivery tool can be
removed from the well and the fracturing fluid delivery equipment
connected to the well, or the fracturing fluid delivery equipment
can be associated with the well, and the lubricator isolated from
the pressure and flow of the fracturing fluid, while the fluid is
being delivered, in this manner the conveyance structure and laser
delivery tool may be left within the well during fracturing,
partially removed from the well, or entirely removed from the well,
and combinations and variation of these.
[0133] The formation 1002 has various geological formations and
properties, e.g., 1004a, 1004b, 1004c. The geological properties
and characteristic of the formation and hydrocarbon deposit may
have been previously determined by seismic, well logging and other
means known to the arts. Based upon this information a custom laser
energy delivery perforating pattern 1120 was designed to extend
from borehole 1003 and is delivered to the formation 1002. The
laser perforating pattern 1120 has a series of laser perforations
1121a-1121s.
[0134] The position, spacing and orientation of these laser
perforations 1121a-1121s is based in whole, or in part, upon the
characteristics and features of the formation in which the laser
pattern is delivered. As can be seen from FIG. 2, and for
illustration purposes the perforation may have different lengths,
may have different orientations to vertical, may have different
angles with respect to the longitudinal axis of the borehole, and
combinations and variations of these and other properties.
Preferably, the perforation pattern and laser delivery pattern,
because of its fracturing and weakening effect on the formation, is
predetermined to enhance, augment, redo, or even replace hydraulic
fracturing.
[0135] Turning to FIG. 3 there is shown an embodiment of laser
fracturing zone. A borehole 1140 in a section of a formation 1141.
An essentially horizontal laser perforation pattern 1142 has been
made from the borehole, resulting in a predetermined laser effected
zone 1143, e.g., custom geometry (shown in dashed lines), which
zone has laser induced fracturing. Hydraulic fracturing operations
can then be applied using this custom geometry, to further enhance
fluid communication between the borehole and the formation.
Preferably, the hydraulic fracture zone 1150 is extended from the
well bore, to and beyond the laser effected zone 1143. In this
manner, the surface area exposed in the formation from the
fracturing, is equal to the laser effected zone, and preferable
larger, and substantially larger than the laser effected zone.
[0136] Turning to FIG. 4 there is shown a borehole 1240 in a
section of a formation 1241. The borehole has a single laser
perforation 1244. A single perforation is used in this figure to
illustrate the different variables that are controllable through
laser perforation and which can, in whole or in part, be used to
provide a predetermined laser perforation delivery pattern, and
custom volumetric removal. The laser perforation can be varied in
length 1243. The angle 1245 that the perforation forms with the
longitudinal axis of the borehole (also typically the laser
perforation tool) can be varied. The orientation around the
borehole, e.g., degrees 1246 around the borehole can be varied,
e.g., for 0.degree. to 90.degree. to 180.degree. to 270.degree. to
0.degree., and thus, any point point around 360.degree..
Additional, since it is preferred to have a multiple perforations,
there spacing can be varied, and the other variables can be changed
from one adjacent perforation to the next. This ability to
predetermine and adapt these variables provides the further ability
to have predetermined volumetric removals, and adaptive volumetric
removals to conditions, data and information that develop during
fracturing, fracturing stages, production, and combinations and
variations of these, as well as, other down hole conditions.
[0137] Turning to FIGS. 38A and 38B there is shown an axil planer
view and cross sectional view of a laser perforating geometry in a
formation in relation to the stress planes in the formation. Thus,
there is a laser tool 3800 in a borehole 3801 in a formation 3807
that has a stress direction shown by arrows, e.g., 3802. The laser
tool 3800 has a range or area 3803 where the laser beam can be
delivered, which for example could be a fan shaped delivery
volumetrically removing the entire area. This area is within and
the direction of stress 3802, and thus, the laser tool 3800 can
deliver the laser beam in the direction of the stress, following
the direction of stress, and parallel to the direction of stress.
The limited ability of conventional tools is shown by perforation
range 3810.
[0138] In additional to providing an entire laser perforation
pattern based upon formation information, in whole, in part or
without such information, it is possible to construct an evolving
or adaptive laser perforation pattern based upon real time data and
information, such as pressure testing in the well. Thus, for
example, straddle packers may be employed with the laser
perforation tool. The packers are set and the area is pressured up;
changes, as measured with a caliper assembly for example, are then
measured. From this information the strength of the formation and
its strength in different directions can be measured and used to
direct the laser beam to provide the optimum configuration of laser
perforations for that specifically tested section of the formation.
Additionally, sonic wireline tools may also be utilized to measure
stress direction.
[0139] Turning to FIGS. 5A and 5B there are shown in FIG. 5A a
prospective view a section of a formation 5050, and in FIG. 5B a
cross sectional view of the formation 5050. The formation 5050 is
shown as being freestanding, e.g., a block of material, for the
purpose of clarity in the figure. It being understood that the
formation may be deep within the earth, nearer to the surface such
as in some shale gas fields, and preferably in a hydrocarbon rich
or pay zone of the formation, and that the face 5051 forms a part
of, or is adjacent to, a borehole 5052 (as seen in FIG. 5B).
Further although some boreholes are represented as being vertical,
this is merely for illustration purposes and it should be
recognized that the boreholes may have any orientation.
[0140] A laser cut hole 5080 extends into the formation 5050 from
the hole opening 5083 to the back of the hole 5081. Around the hole
5080 is an area 5085 of laser affected formation. In this area 5085
the formation is weakened, substantially weakened, fractured or
essentially structurally destroyed. Additionally, the laser cutting
process forms cracks or fractures, i.e., laser induced fracturing,
in the formation. By way of example, fracture 5090a is an
independent fracture and does not extend to, or into, the laser
affected area 5085, the hole 5080 or another fracture. Fracture
5090b extends into and through the laser affected area 5085 into
the hole 5081. Additionally, fracture 5090b is made up of two
associated cracks that are not fully connected. Fracture 5090c
extends to, and into, the laser affected area 5085 but does not
extend to the hole 5080. Fracture 5090d extends to, but not into
the laser affected area 5085.
[0141] The fractures 5090a, 5090b, 5090c and 5090d are merely
schematic representation of the laser induced fractures that can
occur in the formation, such as rock, earth, rock layer formations
and hard rocks, including for example granite, basalt, sandstone,
dolomite, sand, salt, limestone and shale rock. In the formation,
and especially in formations that have a tendency, and a high
tendency for thermal-mechanical fracturing, in a 10 foot section of
laser cut hole there may be about 10, about 20, about 50 or more
such fractures, and these fractures may be tortious, substantially
linear, e.g., such as a crack along a fracture line, interconnected
to greater and lessor extents, and combinations and variations of
these and other geometric and volumetric configurations. These
laser fractures may also be of varying size, e.g., length,
diameter, or distance of separation. Thus, they may vary from micro
fractures, to hairline fractures, to total and extended separation
of sections having considerable lengths. These laser induced
fractures may open up, provide or give rise to, additional surface
area for the flow of hydrocarbons. Further, these laser induced
fractures provide additional paths for fracturing fluid to move
through and extend out from the borehole, and provide the ability
for the fracturing fluid to leave proppant behind in these an other
fractures in the laser effected zone and extending out beyond that
zone. Thus, resulting in a substantial increase in total exposed
surface area from a laser hydraulic fracture than would be obtained
from conventional fracturing alone.
[0142] The depth or length of the lase cut hole can be controlled
by determining the rate, e.g., inches/min, at which the hole is
advanced for a particular laser beam, configuration with respect to
the work surface of the formation, and type of formation. Thus,
based upon the advancement rate, the depth of the hole can be
predetermined by firing the laser for a preset time.
[0143] The rate and extent of the laser fracturing, e.g., laser
induced crack propagation, may be monitored by sensing and
monitoring devices, such as acoustical devices, acoustical
geological sensing devices, and other types of geological, sensing
and surveying type devices. In this manner the rate and extent of
the laser fracturing may be controlled real time, by adjusting the
laser beam properties based upon the sensing data.
[0144] Cuts in, sectioning of, and the volumetric removal of the
formation down hole can be accomplished by delivering the laser
beam energy to the formation in preselected and predetermined
energy distribution patterns. These patterns can be done with a
single laser beam, or with multiple laser beams. For example, these
patterns can be: a linear cut; a pie shaped cut; a cut appearing
like the shape of an automobile cam shaft; a circular cut; an
elliptical cut; a square cut; a spiral cut; a pattern of connected
cuts; a pattern of connected linear cuts, a pattern of radially
extending cuts, e.g., spokes on a wheel; a circle and radial cut
pattern, e.g., cutting pieces of a pie; a pattern of spaced apart
holes, such as in a line, in a circle, in a spiral, or other
pattern, as well as other patterns and arrangements. The patterns,
whether lines, staggered holes, others, or combinations thereof,
can be traced along, e.g., specifically targeted in a predetermined
manner, a feature of the formation, such as, a geologic joints,
bedding layers, or other naturally occurring features of a
formation that may enhance, exploited or built upon to increase the
fluid connectivity between the borehole and the hydrocarbons in the
formation.
[0145] Thus, for example, in determining a laser beam delivery
pattern to provide a predetermined and preselected laser beam
energy distribution pattern, the spacing of cut lines, or staggered
holes, in the formation, preferably may be such that the laser
affect zones are slightly removed from one another, adjacent to one
another but do not overlap, or overlap only slightly. In this
manner, the maximum volume of the formation will be laser affect,
i.e., weakened, fractured or perforated with the minimum amount of
total energy.
[0146] FIG. 6 shows an embodiment of a stepping down fan
perforating pattern that can be implemented with the present laser
perforation tools. In this pattern a series of progressively
smaller fan shapes 2262a, 2262b, 2262c, 2262d are cut into
formation 2261 moving away from borehole 2260. The dashed lines
indicated the end of a first fan pattern that was cut through with
the deeper, and later in time, fan pattern.
[0147] FIG. 7A is a plan view looking down borehole 2300 showing an
embodiment of a fan, or pie shape perforation 2301 in formation
2302. FIG. 7B is a perspective view along the longitudinal axis of
borehole 2300 showing that pie shape perforation 2301 is a
volumetric shape extending along the borehole 2300. The length of
pie shaped perforation 2301 may be a few inches to a few feet, tens
of feet or more. Additionally more than one pie shaped perforation
can be space along the length of the borehole.
[0148] FIG. 8A is a plan view looking down borehole 2400 showing an
embodiment of a fan, or pie shape perforation 2401 in formation
2402. FIG. 8B is a perspective view along the longitudinal axis of
borehole 2400 showing that there are a number of pie shape
perforation 2401, 2403, 2405, 2407, 2409, 2411, 2413 spaced along
the length of the borehole 2400 and that each is a volumetric shape
extending along the length of the borehole 2400. The length of pie
shaped perforation 2401, 2403, 2405, 2407, 2409, 2411, 2413, may be
a few inches to a few feet, tens of feet or more. Their lengths,
and their spacing may be uniform, or it may be staged to, for
example, match to formation characteristics to optimize fluid
communication between the borehole and the formation.
[0149] FIG. 9A is a plan view looking down borehole 2500 showing an
embodiment of a disk shaped perforation 2501 in formation 2502.
FIG. 9B is a perspective view along the longitudinal axis of
borehole 2500 showing that there are a number of disk shape
perforation 2501, 2503, spaced along the length of the borehole
2501 and that each is a volumetric shape extending along the length
of the borehole 2500. The length of disk shaped perforation 2501,
2503 may be an inch, few inches to a few feet, but should not be so
long as to adversely effect the stability of the well bore. Their
lengths, and their spacing may be uniform, or it may be staged to,
for example, match to formation characteristics to optimize fluid
communication between the borehole and the formation.
[0150] The laser perforation patterns, beam delivery patterns have
the capability to remove controlled volumes of material for each
perforation, or discrete geometric shape. Thus, the volumetric
removals, for discrete shape, e.g., disc, cylinder, line, could be
greater than about 0.1 cubic inches (in.sup.3), greater than about
0.2 in.sup.3, greater than about 1 in.sup.3, greater than about 4
in.sup.3, greater than about 20 in.sup.3, greater than about 50
in.sup.3, and greater than about 100 in.sup.3, and greater than
about 150 in.sup.3 (it being understood that greater and lessor
volumes of removal are also contemplated) The laser beam removes
material by, among other things, spalling, melting, vaporizing and
combinations of these processes. For example the following Table 1
provides volumetric removals for a discrete shape, i.e., a disc,
for particular casing, disc outer diameter and thickness.
TABLE-US-00001 TABLE 1 Disc OD 5 Disc OD 5 Disc OD 5 Disc OD 7 Disc
OD 7 Disc OD 7 in, thickness in, thickness in, thickness in,
thickness in, thickness in, thickness 1/4 in - - - 1/2 in - - - 1
in - - - 1/4 in - - - 1/2 in - - - 1 in - - - Casing/pipe volume
volume volume volume volume volume outer removed in removed in
removed in removed in removed in removed in diameter in in.sup.3
in.sup.3 in.sup.3 in.sup.3 in.sup.3 in.sup.3 1 4.71 9.42 18.84 9.42
18.84 37.68 21/2 3.68 7.36 14.72 8.39 16.78 33.56 5 1.77 3.54 7.08
12.76 25.52 51.04 41/2 0.93 1.86 3.72 5.64 11.28 22.56 Disc OD 10
Disc OD 10 Disc OD 10 Disc OD 20 Disc OD 20 Disc OD 20 in,
thickness in, thickness in, thickness in, thickness in, thickness
in, thickness 1/4 in - - - 1/2 in - - - 1 in - - - 1/4 in - - - 1/2
in - - - 1 in - - - volume volume volume volume volume volume
removed in removed in removed in removed in removed in removed in
in.sup.3 in.sup.3 in.sup.3 in.sup.3 in.sup.3 in.sup.3 71/2 28.23
17.18 34.36 67.49 134.98 269.96 75/8 27.87 16.46 32.92 67.13 134.26
268.52 85/8 24.68 10.08 20.16 63.94 127.88 255.76
[0151] Laser perforating tools and operations may find considerable
uses, for example, in shales and shale formations and other
unconventional or difficult to produce from formations. For
example, in shales for unconventional extraction of gas and oil
there is essentially no permeability, and in many cases no
permeability. The current operations to access this rock and make
it productive are to drill a 6 to 12 inch diameter borehole,
thousands of feet long with a mechanical rig and bit, and then
perforate on the order of inches using explosives. Once the
perforations are formed tens or hundreds of thousands of gallons of
fracturing fluid containing propping agents are pumped into the
well at high pressure and are used to create fractures which
increased the productivity of the well.
[0152] The high power laser perforating tools can greatly improve
on this conventional operation by creating a custom geometry (e.g.
shape, length, entrance area, thickness) with a laser. This custom
geometry can stem off a main borehole in any orientation and
direction, which in turn will initiate a fracture that is more
productive than existing conventional methods, by exposing more
rock and positioning the fractures in optimum stress planes,
resulting in even greater surface area upon hydraulic
fracturing.
[0153] Generally, fracturing in rocks at depth is suppressed by the
confining pressure, from the weight of the rocks and earth above.
The force of the overlying rocks is particularly suppressive of
fracturing in the situation of tensile fractures, e.g., Mode 1
fractures. These fractures require the walls of the fracture to
move apart, working against this confining pressure.
[0154] Hydraulic fracturing or fracing is used to increase the
fluid communication between the borehole and the formation. Thus,
it can restore, maintain, and increase the rate at which fluids,
such as petroleum, water, and natural gas are produced from
reservoirs in formations.
[0155] Thus, it has long been desirable to create conductive
fractures in the rock, which can be pivotal to extract gas and oil
from, for example, shale reservoirs because of the extremely low
natural permeability of shale, which is measured for typical shales
in the microdarcy to nanodarcy range. These fractures provide a
conductive path connecting a larger volume of the reservoir to the
borehole.
[0156] The custom geometries that can be created with laser
perforating can provide enhanced, more predictable, and more
controllable predetermined conductive paths that result from
hydraulic fracturing. Thus, the laser perforation custom geometry
can increase the efficiency of hydraulic fracturing and hydrocarbon
production from a well.
[0157] Laser perforated custom geometries for hydraulic fracturing
have many advantages in many, if not all well types, and
particularly have advantages in horizontal drilling, which involves
wellbores where the borehole is completed as a "lateral" that
extends parallel to the hydrocarbon containing rock layer. For
example, lateral boreholes can extend 1,500 to 5,000 feet (460 to
1,500 m) in the Barnett Shale basin in Texas, and up to 10,000 feet
(3,000 m) in the Bakken formation in North Dakota. In contrast, a
vertical well only accesses the thickness of the rock layer,
typically 50-300 feet (15-91 m). Mechanical drilling, however,
typically causes damage to the pore space, e.g., formation
structure, at the wellbore wall, reducing the permeability at and
near the wellbore. This reduces flow into the borehole from the
surrounding rock formation, and partially seals off the borehole
from the surrounding rock. Custom geometries, from the laser
perforation, enable hydraulic fracturing in these wells to provide,
restore and increase permeability and the productivity of the well;
and to also do so in a more efficient and potentially cost
effective manner than with previous perforating practies.
[0158] Thus, laser hydraulic fracturing, its systems tools and
methods, as well as, the laser perforating tools, and laser energy
distribution patterns, which can provide custom geometries, laser
fractures and customer volumetric removals for hydraulic fracturing
operations, have the potential to greatly increase hydrocarbon
production, especially form unconventional sources.
[0159] Turning to FIG. 34, there is provided an embodiment of a
laser hydraulic fracturing assembly 900 deployed in a borehole at
the beginning of a laser hydraulic fracturing operation.
[0160] In general, embodiments of laser hydraulic fracturing
assemblies can have the capability to perform perforating
operations in several predetermined zones or sections of the
borehole. They can also preferably have the capability to isolate
those sections, and to have the laser tool remain in the borehole
during a pressure or flow operations, such as a hydraulic
fracturing operation, if one should be required.
[0161] Thus, in general, a laser tool is located inside a sleeve,
which is inserted into the borehole. (The sleeve may be lowered
into the borehole via any type of conveyance structure, however, if
flow or pressure operations are intended it should preferably be
lowered via coiled tubing.) The sleeve has a series of spaced apart
packers assemblies. These packer assemblies are configured to have
the capability to expand outwardly and seal against the borehole
wall, and also to expand inwardly and seal against the laser tool
or the high power laser conveyance structure.
[0162] Thus, the outer packers can seal against the borehole wall
isolating a section of the borehole between them. The inner packers
can seal against the laser tool, effectively creating a plug (which
also protects the laser optical components and other components of
the laser tool from any high pressures or flows that may be above
the "plug.") In this manner the laser hydraulic fracturing assembly
has the capability to perform many varied perforation, cutting,
welding, pressure, and flow operations; to perform these operations
in multiple predetermined and isolated sections along the length of
the borehole; and to perform these multiple operations along the
length of the borehole while remaining in the borehole.
[0163] Thus, for example, a laser fracturing assembly can be
lowered to the bottom of a borehole. The sleeve of the laser
fracturing assembly has, for example, 10 sets of outwardly
expanding spaced apart packers, which are distributed along the
length of the sleeve. The lower most (closest to the bottom of the
borehole) set of packers on the sleeve are expanded and isolate a
section of the borehole between them.
[0164] The laser tool is positioned inside of the sleeve in the
section of the sleeve between to the two expanded packers. The
laser tool delivers the laser beam, readily cutting through the
sleeve and performing the desired laser perforating operation on
the borehole (either cased, multiple casing, or open hole).
[0165] The laser tool is then moved to a position in the sleeve
adjacent the lower most expanded packer. When the laser tool is at
this position, the inner packer is activated, expanding inwardly,
sealing against the laser tool and creating a plug (e.g., the inner
packer sealing against the laser tool and the adjacent outer
packer, which is still activated sealing against the bore hole). A
pressure and flow operation, e.g., hydraulic fracturing can then be
performed on the isolated section of the borehole.
[0166] Once completed, the next set of up-hole packers can be
expanded and the laser tool moved into position and the process
repeated. In this manner, the laser tool, and related operations,
can move in a serial manner from the down hole packer set (closest
to the bottom of the borehole) to the upper most packer set
(closest to the top of the hole).
[0167] It should further be understood, that this assembly provides
great flexibility in the number and types of processes, operations,
perforation patterns, reperforation patterns, hydraulic fractures,
and other procedures and operations that can be performed along a
length of a borehole, in isolated section of the borehole along
that length, and preferably that can be performed in a single down
hole trip.
[0168] Turning again to the embodiment of FIG. 34, the laser
hydraulic fracturing assembly 900 is attached by joint 904 to coil
tubing 903. The coil tubing 903 has been used to lower the laser
hydraulic fracturing assembly 900 into a desired position within
the borehole 901, in formation 902. Positioned within assembly 900
is laser cutting or perforating tool 910. Laser perforating tool
910 may be moved into the borehole with assembly 900, or it may
moved into position after assembly 900 is situated in the
borehole.
[0169] Assembly 900 has a sleeve or outer housing 920, with a
series of packer assemblies 905, 906, 907, 908, located along the
length of the sleeve 920. In this embodiment packer assembly 908
would be the bottom most assembly, e.g., closest to the bottom of
the borehole, and packer assembly 905 would be the upper most
assembly, e.g., closes to the top of the borehole. More or less
packer assemblies may be used on a laser hydraulic fracturing
assembly. Each packer assembly has an outer expandable sealing
member 905a, 906a, 907a, 908a, and an adjacent inner expandable
sealing member 905b, 906b, 907b, 908b. These packer assemblies are
spaced, e.g., positioned along the length of the sleeve 920 of the
laser hydraulic fracturing assembly 900. They provide predetermined
locations, sections or zones where laser perforations can be made.
They also provide for the performance of flow and pressure
operations, through the laser perforations, on these isolated
sections of the borehole, such as for example, where fracturing
fluid and pressures will be applied to the formation 902. Thus,
their number, spacing and frequency can vary and will be
determined, in part, by information regarding the nature and
characteristics of the formation and hydrocarbon sought to be
recovered.
[0170] The laser perforating tool 910 has a high pressure sealing
section 911. This section is configured to seal against the laser
conveyance structure 916, and be engaged by, and thus seal against
the inner sealing member, e.g., 908b, when that sealing member is
extended inwardly. In this manner the sealing section 911 when
engaged by an inner sealing member protects the the laser
perforating tool 910 from any up hole conditions, such as for
example, the pressures and flows from an hydraulic fracturing
operation. The laser sealing section 911 may also have its own
expandable device, which could be expanded to engage the inner
sealing member 908b, or could be expanded to engage and seal
against the inner wall of the sleeve 920, or even potentially
against the inner wall of another tubular located around the laser
tool. (In this manner, the position of the laser perforating tool
910 would not be limited to being adjacent a packer assembly, e.g.,
908, during an hydraulic fracturing stage).
[0171] The laser perforating tool 910 has a laser cutter section
912, which may contain a laser optics package for shaping and
determining the laser beam properties, a mirror or prism for
changing the direction of the laser beam, and a beam steering
assembly for scanning or otherwise directing the laser beam. For
example, the cutter section may have a digital micromirror device
("DMD") to direct the laser beam in a predetermined path, to give
rise to a predetermined volumetric removal. The laser cutter
section 912 may also have a nozzle, jet or other components to
assist in the delivery of the laser beam, along a predetermined
laser beam path, to it is target.
[0172] The laser cutter section 912 is optically associated with
the conveyance structure 916, by for example, a high power
connector. The conveyance structure 916 transmits the high power
laser beam from a high power laser, preferably above the surface,
to the cutting head section 912, where it is launch toward the
target, e.g., the borehole wall. The conveyance structure 916 may
be a high power optical fiber having a core diameter of at least
about 300 microns, an inner protective sleeve of for example
Teflon, which is located between the exterior of the optical fiber
and the inner surface of a metal tube. The metal tube is then
wrapped with carbon fiber, preferably in a braided fashion to
provide strength to the metal tube and reduce, if not prevent the
stretching of the tube. The woven carbon fiber outer wrap is then
impregnated with an abrasion resistant resin or coating, which is
also preferably high temperature, such as polyimide. The conveyance
structure may also include other line structures for data, power,
hydraulics for the the laser perforating tool 910, or these lines
to the extent needed may be places in one or more other conveyance
structures.
[0173] The laser perforating tool 910 has an instruments section
913, which may have position location equipment, logging equipment,
sensors and the like. In particular and preferably, the instrument
section 913 has a locator device that can detect and determine the
position of the laser perforating tool 910 with respect to a packer
assembly, e.g., 908.
[0174] The laser perforating tool, has a motive section 914, which
may contain an axial extending device, such as a ball screw
assembly, for moving the laser cutting head in a predetermined and
controlled rate axially along the length of the borehole. Depending
upon the laser beam steering capabilities of the laser cutter
section 912, the laser motive section 914 may also have a rotation
device for rotating the laser head to a particular orientation
regarding the borehole (see, e.g., FIG. 4, item 1246).
[0175] The laser perforating tool 910 has a tractor section 915,
which can be used to initially position the tool 910 in the coiled
tubing, can be used to move the tool from one section of packer
assemblies to the next, e.g., moving from packer assembly 908 to
packer assembly 907. The tractor section 915 may also serve to
anchor the tool 910 as the laser cutting head is moved during a
laser perforating operation, and to anchor the tool 910 when the
inner sealing members are sealed during a fracturing stage.
Depending up the vertical slope of the borehole, the tractor
section 915 may only be an anchoring section as the movement of the
tool 910 in the borehole can be accomplished by gravity and the
lowering or rising of the conveyance structure 916.
[0176] This embodiment of the laser hydraulic fracturing assembly
900 and its laser perforating tool 910 are illustrative. Thus,
additional and different components of the various sections may be
used, additional or fewer sections may be used, the components of
one section may be located in a different section, duplicate and
redundant components may be used, and the the functions of one
component may be spread across or combined with other components.
Preferably, the various sections of the laser perforating tool
provide the tool with the capability to perform precision and
predetermined volumetric removals by directing and moving the laser
beam in predetermined angles and patterns, for example, as shown in
and described regarding the embodiment of FIG. 4.
[0177] The laser hydraulic fracturing assembly 900 provides many
varied methods of operation to perform laser hydraulic fractures.
Turning to FIG. 9, the tractor section 915 is anchored against the
inner wall of the sleeve 920. The laser cutter is moved at a
predetermined rate and manner by the motive section 914. In this
example the laser cutter is moved axially for a distance of three
feet between packer assembly 908 and assembly 907, to perforate the
borehole, by cutting a slot in the borehole wall and formation. The
laser readily cuts through sleeve 920, which does not interfere
with the laser perforation of the borehole. (To the extent that the
packer assemblies are a greater distance apart, for example 15
feet, and the length of the slot is desired to be 10 feet, once the
full extension of the motive device 914 is reached, e.g., 3 feet,
the tractor can be moved forward as the motive device is retracted,
the tractor can then be anchored and the cut continued.) In
addition to a slot, the laser cutter could be moved and create
holes at predetermined locations, or any other predetermined
perforation pattern.
[0178] Once the desired laser perforations are made the laser
cutter 912 is retracted back by the motive section 914, to the
point where the sealing section 911 is adjacent to the inner packer
908b. At this point the inner packer 908b is sealed against the
sealing section 911. The inner packer 908b and the sealing section
911 form a pressure tight seal. This seal has sufficient strength,
e.g., is sufficiently tight and strong, to withstand the pressures
and flows during e.g., a fracturing operation. The outer sealing
member 908a of packer assembly 908 and the outer sealing member
907a of packer assembly 907 are then extended to seal against the
inner surface of the borehole 901. In this manner the packer
assembly 908, in conjunction with sealing section 911 form a plug
in the borehole, as shown in FIG. 34A. Further, in this manner
packer assemblies 907 and 908 form an isolation zone along the
length of the borehole.
[0179] Once the packers sealing members 907a, 908a, and 908b are
set, hydraulic fracturing can begin. The fracturing fluid is pumped
down the coiled tubing 903, into the sleeve 920, out of the sleeve
through the laser cut openings, and into the laser perforations in
the formation fracturing the formation.
[0180] As the pressures and flows are monitored, if it is believed
that less than optimal fracturing is occurring, the pressure and
flow of the fracturing fluid can be reduced and stopped. The packer
908b can be disengaged, and subsequent laser cutting, and
perforating operations, can be commented in the section between
packer assembly 908 and 907. Once the subsequent, adaptive, laser
perforation is completed, the cutter head 912 is retracted, the
inner seal 908b is set, and the hydraulic fracturing can be
continued. In this manner, real time monitoring and adaptive
perforation of the well can be performed to optimize the hydraulic
fracturing operation. (It should also be noted that these seals can
be used to control the beam path free space environment, by for
example, filling the free space with a gas, such as nitrogen, or a
liquid, such as D.sub.2O, which is preferred if the laser
wavelength is about 1070 nm, or with a different fluid that is
selected to provide minimal transmission losses to a particular
laser beam wave length.)
[0181] This procedure can then be repeated, moving for example in a
serial fashion up hole, from one packer section to the next, e.g.,
908-907 to 907-906 to 906-905. With each section having an adaptive
and optimized laser perforation and hydraulic fracturing procedure
performed on it, should such a procedure be needed.
[0182] It being recognized that in this configuration and procedure
the conveyance structure(s) will be exposed to the high pressures,
flow and abrasive effects of the fracturing fluid and proppants.
Thus, preferably for such configurations the conveyance structure
should be coated with a friction reducing, abrasion resistant outer
coating, which is also preferably high temperature and strong.
[0183] In various embodiments and various applications, and by way
of illustration, a laser perforating tool may have several
components or sections. The tool may have a one or more of these
and similar types of sections: a conveyance structure, a guide
assembly, a cable head, a roller section, a casing collar locating
section, a swivel, a LWD/MWD section, a vertical positioning
section, a tractor, a packer or packer section, an alignment or
orientation section, laser directing aiming section, a packer, and
a laser head. These components or sections may be arranged in
different orders and positions going from top to bottom of the
tool. In general, and unless specified otherwise, the bottom of the
tool is that end which first enters the borehole and the top of the
tool is that section which last enters the borehole and typically
is attached to or first receives the conveyance structure. It is
further understood that one component in the tool may perform the
functions of two or more other components; that the functions of a
single component may be performed by one two or more components;
and combinations and variations of these.
[0184] Embodiments and applications for laser hydraulic fracturing,
perforating of tubing and casing, open holes, and embodiments of
laser tools, systems, methods and devices are shown in FIGS. 10, 11
and 12. In these embodiments the perforating of casing and tubing
is done as a means of establishing communication between two areas
previously isolated. The most common type of perforating done is
for well production, the exposure of the producing zone to the
drilled wellbore to allow product to enter the wellbore and be
transported to surface facilities. Similar perforations are done
for injection wells, providing communication to allow fluids and or
gases to be injected at the surface and placed into formation.
Workover operations often require perforating to allow the precise
placement of cement behind casing to ensure adequate bond/seal or
the establishing of circulation between two areas previously sealed
due to mechanical failure within the system. Such workover
operations can can be accomplished and enhanced by the present
laser systems and methods.
[0185] In the embodiments of FIGS. 10-12, the laser system for
perforating includes a laser cutting head 7701, 7801, 7901, which
propagates a laser beam(s) 7709, 7809, 7909a and 7909b, an
anchoring or an anchoring/tractor device, 7704, 7804, 7904 an
imaging tool and a direction/inclination/orientation measurement
tool. The assembly is conveyed with a wireline style unit and a
hybrid electric line. The assembly is capable of running into a
well and perforating multiple times through the wellbore in a
single trip, with the perforations 7910 specifically placed in
distance, size, frequency, depth, and orientation. The tool is also
capable of cutting slots in the pipe to maximize exposure while
minimizing solids production from a less-than-consolidated
formation. In a horizontal wellbore, the tractor 7904 is engaged to
move the assembly while perforating. (In vertical uses the tractor
assemblies 7704, 7804 may also be used to position the tool)
Further, to the extent sufficient control or precision can not be
obtained by the tractor assembly, a precision advancement mechanism
can be used to move the laser head in an axial direction along the
length of the borehole at a very precise rate, such precision axial
movement mechanisms would include, ball nut and screw, hydraulic
piston, chain drive, gear drive and the like. The tool is capable
of perforating while underbalanced, even while the well is
producing, allowing evaluation of specific zones to be done as the
perforating is conducted. The tool is relatively short, allowing
deployment methods that are significantly easier than traditional
underbalanced perforating systems.
[0186] Turning specifically to FIG. 10 the tool is positioned above
a packer 7740 to establish an area to be perforated that has an
established circulation. Turning to FIG. 11, the tool is being used
to cut access to an area of poor cement bond 7850. In this manner
additional cement could be pumped in.
[0187] Turning to FIG. 13 there is provided a perspective view of
an embodiment of a laser perforating tool with a conveyance
structure attached, for use in laser hydraulic fracturing
operations. The laser perforating tool 100 contains several
connectable and cooperatively operable subassemblies forming an
elongated housing that may be joined together by threaded unions,
or other connecting means know to the art, into an operable piece
of equipment for use. At the top 120 of tool 100 is a conveyance
structure 101, which is mounted with the tool 100 at a cable head
102. A guide assembly 121 is mounted around conveyance structure
101 immediately above cable head 102. Housing guide assembly 121 is
freely rotatedly mounted around the conveyance structure 101 and
provided with a roller or wheel and a sliding shoe or guide portion
122 which enables the tool to be pulled into a reduced diameter
aperture such as when the tool is pulled from a lower portion of
well casing through a bulkhead or the like into a shorter tubing
string. Guide assembly 121 prevents the the upper end portion of
cable head 102 from becoming stuck or wedged against the
obstruction created by a reduced diameter aperture within a well
casing. Adjacent cable head 102 is upper roller assembly 103. Upper
roller assembly 103 contains a number of individual rollers, e.g.,
123 mounted in a space relation around and longitudinally along
this section. Rollers 123 protrude from the outer surface 124 of
the upper roller assembly housing in order to support the housing
on the interior tubular surface presented by well casing and
tubing. Rollers 123 in this roller assembly can be constructed with
low friction bearings and/or materials so that rotation of the
rollers requires very little force, other devices for reducing the
force required for movement through the borehole, know to those of
skill in the art may also be used. This construction assists in
longitudinal movement of the housing through the tubing and casing
of a well by significantly reducing the force required to
accomplish such movement. Below upper roller assembly 103 is a
connecting segment 104, which joins a casing collar locator 105.
Casing collar locator 105 is used to locate the collars within a
casing of a well. In perforating operations it is typical to locate
several collars within a well in order to determine the exact
position of the zone of interest that is to be perforated, other
instruments and assemblies may also be used to make this
determination.
[0188] With explosive perforation it was necessary or suggested to
locate collars within the casing in order to position the explosive
perforating tool such that it would not attempt to perforate the
casing through a collar. The laser perforating tools have over come
this problem and restriction. The laser beam and laser cutting
heads can readily cut a perforation hole through a casing collar or
joint of any size.
[0189] Immediately below casing collar locator 105 is a swivel sub
106. Swivel sub 106 is constructed with overlapping internal and
external members that provide for a rigid longitudinal connection
between upper and lower portions of the housing while at the same
time providing for free rotational movement between adjoining upper
and lower portions of the housing.
[0190] Immediately below swivel sub 106 in the housing is an
eccentrically weighted sub 107, which provides for passive vertical
orientation, positioning, of the laser sub assembly 170. Eccentric
weight sub 107 contains a substantially dense weight, e.g.,
depleted uranium, that is positioned in an eccentric relation to
the longitudinal axis of the housing. This eccentric weight 125 is
illustrated in dashed lines in its eccentric position relative to
the longitudinal axis of this sub. The position of eccentric weight
125 is on what will be referred to as the bottom portion of the
housing and the laser sub 170. Due to the mass of weight 125 being
selected as substantially larger than the mass of the adjacent
portion of the apparatus housing this weight will cause the housing
to rotate to an orientation placing weight 125 in a downwardly
oriented direction. This is facilitated by the presence of swivel
sub 106. Immediately below eccentric weight sub 107 is an alignment
joint sub indicated at 126. Alignment joint 126 is used to
correctly connect eccentric weight sub 107 with the laser sub 170
so that the bottom portion of the housing will be in alignment with
the laser beam aiming and directing systems in the laser sub
170.
[0191] Laser sub assembly 170 contains several components within
its housing 108. These components or assemblies would include
controllers, circuitry, motors and sensors for operating and
monitoring the delivery of the laser beam, an optics assembly for
shaping and focusing the laser beam, a beam aiming and directing
assembly for precisely directing the laser beam to a predetermined
location within the borehole and in a predetermined orientation
with respect to the axis 171 of the laser sub 170, the beam aiming
and directing system may also contain a beam path verification
system to make certain that the laser beam has a free path to the
casing wall or structure to be perforated and does not
inadvertently cut through a second string or other structure
located within the casing, a laser cutting head which is operably
associated with, or includes, in whole or in part, the optics
assembly and the beam aiming and directing assembly components, a
laser beam launch opening 111, and an end cone 112. The laser sub
170 may also contain a roller section or other section to assist in
the movement of the tool through the borehole.
[0192] Subassemblies and systems for orienting a tool in a well may
include for example, gravity based systems such as those disclosed
and taught in U.S. Pat. Nos: 4,410,051, 4,637,478, 5,101,964, and
5,211,714, the entire disclosures of each of which are incorporated
herein by reference, laser gyroscopes, gyroscopes, fiber gyros,
fiber gravimeter, and other devices and system known to the art for
deterring true vertical in a borehole.
[0193] Turning to FIG. 13A there is shown a cut away perspective
view of the laser perforating sub assembly 170. The laser beam
traveling along beam path 160, from optics assembly (not shown in
the Figure) enters TIR prism 150 (Total internal reflection (TIR)
prisms, and their use in high power laser tools is taught and
disclosed in U.S. patent application Ser. No. 13/868,149, the
entire disclosure of which is incorporated herein by reference.) It
is noted that other forms of mirrors and reflective surfaces may be
used, however these are not preferred. From TIR prism 150 the laser
beam traveling along beam path 160 enters a pair of optical wedges
153, 154, which are commonly called Risley Prisms, and which are
held and controlled by Risley Prism mechanism 152. As the prisms
are rotted about the axis of the laser beam path 160 they will have
the effect of steering the laser beam, such that depending upon the
relative positions of the prisms 153, 154 the laser beam can be
directed to any point in area 161 and can be moved in any pattern
within that area. There is further provided a window 157 that is
adjacent a nozzle assembly 156 that has a source of a fluid
157.
[0194] The conveyance structure transmits high power laser energy
from the laser to a location where high power laser energy is to be
utilized or a high power laser activity is to be performed by, for
example, a high power laser tool. The conveyance structure may, and
preferably in some applications does, also serve as a conveyance
device for the high power laser tool. The conveyance structure's
design or configuration may range from a single optical fiber, to a
simple to complex arrangement of fibers, support cables, shielding
on other structures, depending upon such factors as the
environmental conditions of use, performance requirements for the
laser process, safety requirements, tool requirements both laser
and non-laser support materials, tool function(s), power
requirements, information and data gathering and transmitting
requirements, control requirements, and combinations and variations
of these.
[0195] Turning to FIGS. 14A, 14B and 14C there is provided a
perspective view of an embodiment of a laser perforating tool (FIG.
14B is a cutaway sectional perspective view of the tool of FIG. 14A
and FIG. 14C is a cutaway sectional perspective view of a beam
splitter assembly of the tool). The laser perforating tool 2600,
for use in laser hydraulic fracturing operations, has four laser
beam delivery assemblies 2605, 2606, 2607, 2608, which deliver four
laser beams 2601, 2602, 2603, 2604 to form perforations in the
borehole side wall and formation. Laser beam delivery assemblies,
2605, 2606, 2607 each have a beam splitter, e.g., 2612, in a
housing which has air cooling passage 2609, and laser path openings
2610. The bottom laser delivery assembly 2608 has a TIR prism for
directing laser beam 2604.
[0196] An embodiment of a laser perforating tool may be used to
rework a well that has become less productive, for example, by the
reopening of a perforation zone in a well for subsequent
fracturing. Turning to FIGS. 15A and 15B there is shown a schematic
cross section of an embodiment of a laser perforating tool 700 in a
casing 750, in a well bore 754. The laser perforating tool 700 has
circulating ports 703, for delivering a circulation fluid, e.g.,
gas, liquid or both, to assist in carrying away and out of the well
any removed material. As shown in FIG. 15A the laser tool is being
advanced toward the perforations 751 in the casing 750, which have
been fouled by build up 752. Upon reaching the build up area the
laser tool fires the laser beam 702 at the build up causing its
removal. The laser beam is scanned around the inner diameter of the
casing to remove all of the build up. Based upon sensors in the
laser tool when the laser beam reaches a perforation 751, scanning
of the beam is suspended, and the beam is held on the perforation
until it is cleared of the build up.
[0197] Turning to the embodiment of FIGS. 16, 16A, and 16B there is
provided an embodiment of a laser head and optics assembly for use
in a laser hydraulic fracturing assembly and laser perforation
tool. In this embodiment, the laser head 1400 has an outer body
1405 that has three openings 1402, 1403, 1404. The laser beam in a
linear pattern is propagated through those openings. Turning to
FIG. 16A, the optics assembly 1410, which is within laser head
1400, is shown. The optics head 1410 has a laser beam receiving or
input face 1411 and three angular laser beam launch members 1412,
1413, 1414. Each laser beam launch member has a laser beam launch
face 1417, 1416, and 1415. Turning now to FIG. 16B, which by way of
example shows a cross sectional view of angular launch member 1412,
the member has faces 1420, 1421, 1422 1423 (and side faces not
shown) that reflect, and thus, direct the laser beam to and out of
face 1417. These reflective faces may be obtained through the use
of total internal reflection (TIR), reflected coatings, and
combinations and variations of these.
[0198] The launch faces, e.g., 1417, of the optics assembly,
preferably should be protected from dirt and debris. This may be
accomplished by several means. For example, the faces may be
slightly recessed within the body 1405 of the head 1400 with
channels in, or associated with, the body directing a fluid across
and away from the face. The face may be optically coupled to, or
have within it, micro channels that are configured to form fluid
jets into which the laser beam is coupled in the microchannel. A
fluid stream could be flowed annularly down, or more preferably up,
to help clear away debris along the surface of the tool.
[0199] Three staggered launch faces are shown in the embodiment of
FIG. 16. It should be understood that more or less launch faces and
launch members may be employed, that these members may obtain their
laser energy for a single optical fiber, multiple fibers, or each
having their own associated fiber, and that them may be arranged
linearly, or in other patterns. The tool head may be attached to,
or associated with a laser fracturing assembly or a perforation
assembly. This laser head has the capability of having very small
outside diameters, and thus has the capability of being configured
for use in tubulars, channels, passages or pipes that have an
internal diameter of less then about 3'', less then about 2'', less
than about 1'' and smaller. In this manner laser hydraulic
fracturing can be conducted in product tubing, and boreholes have
these smaller diameters.
[0200] Turning to FIG. 17 there is shown a schematic perspective
view of an embodiment of a laser fracturing adapter, which is shown
in a subsea application but which also may be utilized on the
surface. A subsea production tree 301 is located on the sea floor
302 below the surface (not shown in the figure) of a body of water
303. The tree 301 has a permanent riser assembly 350 attached to
it. The permanent riser assembly 350 is in a "Y" configuration,
with one branch 352 extending vertically to provide intervention
access and the other branch 351 providing access for the laser
tool, e.g., a fracturing assembly or laser perforation tool. The
branch 351 has a riser isolation valve 304, a riser clamp 305. The
laser assembly 300 has a deployment valve 306 that is attached to
clamp 305 to connect and hold the laser assembly 300 in association
with riser 350. The laser assembly 300 has a laser tool deployment
housing 307, that forms a cavity 309 in which the laser tool 308 is
housed. When the valves 306 and 304 are opened the cavity 309 is in
fluid communication with the riser branch 351 and the tree 301. The
laser assembly 300 has a laser container 310 that is sealed for
protection from the sea and contains a high power laser 311, a
conveyance reel 312 and a conveyance pack-off 313. The laser
container 310 can be pressure compensated or at atmospheric
pressure. Electric power, fluids of any laser jet, communication
and data links are provided to the laser assembly 300 by umbilical
314. In surface applications the laser container 310 may be
separate, removed and optically connected by a conveyance
structure, and for example, be a laser field unit.
[0201] Turning to FIG. 18 there is provided a schematic of an
embodiment of a laser tool 4500 having a longitudinal axis shown by
dashed line 4508. This tool could be used for, laser hydraulic
fracturing, perforating, as well as, other things, such as pipe
cutting, decommissioning, plugging and abandonment, window cutting,
and milling. The laser cutting tool 4500 has a conveyance
termination section 4501. The conveyance termination section 4501
would receive and hold, for example, a composite high power laser
umbilical, a coil tube having for example a high power laser fiber
and a channel for transmitting a fluid for the laser cutting head,
a wireline having a high power fiber, or a slick line and high
power fiber, or other type of conveyance structure. The laser tool
4500 has an anchor and positioning section 4502. The anchor and
positioning section (which may be a single device or section, or
may be separate devices within the same of different sections) may
have a centralizer, a packer, or shoe and piston or other
mechanical, electrical, magnetic or hydraulic device that can hold
the tool in a fixed and predetermined position longitudinally
(e.g., along the length of the borehole), axially (e.g., with
respect to the axis of the borehole, or within the cross-section of
the borehole) or both. The section may also be used to adjust and
set the stand off distance that the laser head is from the surface
to be perforated.
[0202] The laser tool 4500 has a motor section, which may be an
electric motor, a step motor, a motor driven by a fluid, or other
device to rotate the laser cutter head, or cause the laser beam
path to rotate. The rotation of the laser tool, or laser head, may
also be driven by the forces generated by the jet, either the laser
fluid jet or a separate jet. For example, if the jet exits the tool
at an angle or tangent to the tool it may cause rotation. In this
configuration the laser fiber, and fluid path, if a fluid used in
the laser head, passes by or through the motor section 4503. Motor,
optic assemblies, and beam and fluid paths disclosed and taught in
US Patent Application Publication No. 2012/0267168, the entire
disclosure of which is incorporated herein by reference, may be
utilized. There is provided an optics section 4504, which for
example, may shape and direct the beam and have optical components
such as a collimating element or lens and a focusing element or
lens. Optics assemblies, packages and optical elements disclosed
and taught in US Patent Application Publication No. 2012/0275159,
the entire disclosure of which is incorporated herein by reference,
may be utilized.
[0203] There is provided a laser cutting head section 4505, which
directs and moves the laser beam along a laser beam path 4507. In
this embodiment the laser cutting head 4505 has a laser beam exit
4506. In operation the laser beam path may be rotated through 360
degrees to perform a complete circumferential cut of a tubular.
(The laser beam may also be simultaneously moved linearly and
rotationally to form a spiral, s-curve, figure eight, or other more
complex shaped cut.) The laser beam path 4507 may also be moved
along the axis 4508 of the tool 4500. The laser beam path also may
not be moved during propagation or delivery of the laser beam. In
these manners, circular cuts, windows, perforations and other
predetermined shapes may be made to a borehole (cased or open
hole), a tubular, a support member, or a conductor. In the
embodiment of FIG. 45, as well as some other embodiments, the laser
beam path 4507 forms a 90-degree angle with the axis of the tool
4508. This angle could be greater than 90 degrees or less then 90
degrees.
[0204] The laser cutting head section 4505 preferably may have any
of the laser fluid jet heads provided in this specification, it may
have a laser beam delivery head that does not use a fluid jet, and
it may have combinations of these and other laser delivery heads
that are known to the art.
[0205] Turning to FIG. 19, there is shown an embodiment of a laser
hydraulic fracturing and perforating tool 4600. The laser tool 4600
has a conveyance termination section 4601, an anchoring and
positioning section 4602, a motor section 4603, an optics package
4604, an optics and laser cutting head section 4605, a second
optics package 4606, and a second laser cutting head section 4607.
The conveyance termination section would receive and hold, for
example, a composite high power laser umbilical, a coil tube having
for example a high power laser fiber and a channel for transmitting
a fluid for the laser cutting head, a wireline having a high power
fiber, or a slick line and high power fiber.
[0206] The anchor and positioning section may have a centralizer, a
packer, or shoe and piston or other mechanical, electrical,
magnetic or hydraulic device that can hold the tool in a fixed and
predetermined position both longitudinally and axially. The section
may also be used to adjust and set the stand off distance that the
laser head is from the surface to be cut. The motor section may be
an electric motor, a step motor, a motor driven by a fluid or other
device to rotate one or both of the laser cutting heads or cause
one or both of the laser beam paths to rotate.
[0207] The optics and laser cutting head section 4605 has a mirror
4640. The mirror 4640 is movable between a first position 4640a, in
the laser beam path, and a second position 4640b, outside of the
laser beam path. The mirror 4640 may be a focusing element. Thus,
when the mirror is in the first position 4640a, it directs and
focuses the laser beam along beam path 4620. When the mirror is in
the second position 4640b, the laser beam passes by the mirror and
enters into the second optics section 4606, where it may be
preferably shaped into a larger circular spot (having a diameter
greater than the tools diameter), or a substantially linear or
elongated elliptical pattern, for delivery along beam path 4630.
Two fibers and optics assemblies may used, a beam splitter within
the tool, or other means to provide the two laser beam paths 4620,
4630 may be used.
[0208] The tool of the FIG. 19 embodiment may be used in addition
to perforating, for example, in the boring, sidetracking, window
milling, rat hole formation, radially cutting, and sectioning
operations, wherein beam path 4630 would be used for boring and
beam path 4620 would be used for the axial cutting, perforating and
segmenting of the structure. Thus, the beam path 4620 could be used
to cut a window in a cased borehole and the formation behind the
casing. A whipstock, or other off setting device, could be used to
direct the tool into the window where the beam path 4630 would be
used to form a rat hole; or depending upon the configuration of the
laser head 4607, e.g., if it where a laser mechanical bit, continue
to advance the borehole. Like the embodiment of FIG. 19, the laser
beam path 4620 may be rotated and moved axially. The laser beam
path 4630 may also be rotated and preferably should be rotated if
the beam pattern is other than circular and the tool is being used
for boring. The embodiment of FIG. 19 may also be used to clear,
pierce, cut, or remove junk or other obstructions from the borehole
to, for example, facilitate the pumping and placement of cement
plugs during the plugging of a borehole.
[0209] The laser head section 4607 preferably may have any of the
laser fluid jet heads provided in this specification and in US
Published Application Publication No. 2012/0074110, the entire
disclosure of which is incorporated herein by reference, it may
have a laser beam delivery head that does not use a fluid jet, and
it may have combinations of these and other laser delivery heads
that are known to the art.
[0210] Turning to FIG. 20 there is provided a schematic of an
embodiment of a laser tool. The laser tool 4701 has a conveyance
structure 4702, which may have an E-line, a high power laser fiber,
and an air pathway. The conveyance structure 4702 connects to the
cable/tube termination section 4703. The tool 4701 also has an
electronics cartridge 4704, an anchor section 4705, an hydraulic
section 4706, an optics/cutting section (e.g., optics and laser
head) 4707, a second or lower anchor section 4708, and a lower head
4709. The electronics cartridge 4704 may have a communications
point with the tool for providing data transmission from sensors in
the tool to the surface, for data processing from sensors, from
control signals or both, and for receiving control signals or
control information from the surface for operating the tool or the
tools components. The anchor sections 4705, 4708 may be, for
example, a hydraulically activated mechanism that contacts and
applies force to the borehole. The lower head section 4709 may
include a junk collection device, or a sensor package or other down
hole equipment. The hydraulic section 4706 has an electric motor
4706a, a hydraulic pump 4606b, a hydraulic block 4706c, and an
anchoring reservoir 4706d. The optics/cutting section 4707 has a
swivel motor 4707a and a laser head section 4707b. Further, the
motors 4704a and 4706a may be a single motor that has power
transmitted to each section by shafts, which are controlled by a
switch or clutch mechanism. The flow path for the gas to form the
fluid jet is schematically shown by line 4713. The path for
electrical power is schematically shown by line 4712. The laser
head section 4707b preferably may have any of the laser fluid jet
heads provided in this specification, it may have a laser beam
delivery head that does not use a fluid jet, and it may have
[0211] In holes having a beam angle below horizontal a fluid assist
may be required, depending upon laser power, shape of the
perforation, formation material and other factors. For example,
turning to FIGS. 21 and 21A there is provided the laser perforating
tool 100 of the embodiment of FIG. 13 (as such like numbers refer
to like structures and components). However, the laser head in the
laser sub 170 has an angled fluid jet nozzle 1600. In FIG. 21A,
which is a cross section along line A-A of FIG. 21, it is shown how
the angled fluid jet nozzle 1600 directs the fluid jet 1601 toward
the laser jet 1602 (which jets are not shown in FIG. 21). The laser
beam path within jet 1602 is shown by dashed line 1603. Thus, the
angled jet 1601, and in whole or in part the laser jet 1601,
assists in clearing the perforation hole of debris as the
perforation hole is advanced deeper into the formation.
[0212] FIGS. 22A and 22B show schematic layouts for perforating and
cutting systems using a two fluid dual annular laser jet. Thus,
there is an uphole section 4801 of the system 4800 that is located
above the surface of the earth, or outside of the borehole. There
is a conveyance section 4802, which operably associates the uphole
section 4801 with the downhole section 4803. The uphole section has
a high power laser unit 4810 and a power supply 4811. In this
embodiment the conveyance section 4802 is a tube, a bunched cable,
or umbilical having two fluid lines and a high power optical fiber.
In the embodiment of FIG. 22A the downhole section has a first
fluid source 4820, e.g., water or a mixture of oils having a
predetermined index of refraction, and a second fluid source 4821,
e.g., an oil having a predetermined and different index of
refraction from the first fluid. The fluids are feed into a dual
reservoir 4822 (the fluids are not mixed and are kept separate as
indicated by the dashed line), which may be pressurized and which
feeds dual pumps 4823 (the fluids are not mixed and are kept
separate as indicated by the dashed line). In operation the two
fluids 4820, 4821 are pumped to the dual fluid jet nozzle 4826. The
high power laser beam, along a beam path enters the optics 4824, is
shaped to a predetermined profile, and delivered into the nozzle
4826. In the embodiment of FIG. 22B a control head motor 4830 has
been added and controlled motion laser jet 4831 has been employed
in place of the laser jet 4826. Additionally, the reservoir 4822
may not be used, as shown in the embodiment of FIG. 22B.
[0213] Turning to FIGS. 23A and 23B there is shown schematic
layouts for cutting and perforating systems using a two fluid dual
annular laser jet. Thus, there is an uphole section 4901 of the
system 4900 that is located above the surface of the earth, or
outside of the borehole. There is a conveyance section 4902, which
operably associates the uphole section 4901 with the downhole
section 4903. The uphole section has a high power laser unit 4910
and a power supply 4911 and has a first fluid source 4920, e.g., a
gas or liquid, and a second fluid source 4921, e.g., a liquid
having a predetermined index of refraction. The fluids are fed into
a dual reservoir 4922 (the fluids are not mixed and are kept
separate as indicated by the dashed line), which may be pressurized
and which feeds dual pumps 4923 (the fluids are not mixed and are
kept separate as indicated by the dashed line). In operation the
two fluids 4920, 4921 are pumped through the conveyance section
4902 to the downhole section 4903 and into the dual fluid jet
nozzle 4926. In this embodiment the conveyance section 4902 is a
tube, a bunched cable, or umbilical. For FIG. 23A the conveyance
section 4902 would have two fluid lines and a high power optical
fiber In the embodiment of FIG. 23B the conveyance section 4902
would have two fluid lines, an electric line and a high power
optical fiber. In the embodiment of FIG. 23A the downhole section
has an optics assembly 4924 and a nozzle 4925. The high power laser
beam, along a beam path enters the optics 4924, where it may be
shaped to a predetermined profile, and delivered into the nozzle
4926. In the embodiment of FIG. 23B a control head motor 4930 has
been added and controlled motion laser jet 4931 has been employed
in place of the laser jet 4926. Additionally, the reservoir 4922
may not be used as shown in the embodiment of FIG. 23B.
[0214] Turning to FIGS. 30A-30E there is shown an embodiment of a
laser perforating tool 300 for making precise laser cuts along the
axial direction of the borehole, such as for example slots. The
laser perforating tool 300 has a first centralizer roller assembly
301, a first and second tractor centralizer section 302, 303 and a
laser cutting section with a centralizer roller assembly 304. The
controlled axial advancement of the laser head section 304 is shown
through the progression of FIGS. 30A, to 30B to 30C. The controlled
and predetermined extension and movement of tractor sections 302,
303 relative to each other, and the roller sections 301, 304 is
accomplished by hydraulics, or mechanical advancement devices such
as screws.
[0215] Turning to FIG. 24A to 24D there is shown an embodiment of
an adjustable optics package that may be used in a laser hydraulic
fracturing assembly and a laser perforating tool. FIG. 24A is a
perspective view of the adjustable optics package 6024 with a laser
beam 6027 being propagated, e.g., fired, shot, delivered, from the
front (distal) end 6025 of the optics package 6024. The optics
package 6025 has an adjustment body 6028 that has a fixed ring
6029. The adjustment body 6028 is adjustably, e.g., movably,
associated with the main body 6031 of the optics package 6024, by
threaded members. There is also a locking ring 6032 on the
adjustment body 6028. The locking ring 6029 is engageable against
the main body to lock the adjustment body 6028 into position.
[0216] Turning to FIGS. 24B to 24D, there are shown cross sectional
views of the embodiment of FIG. 24A in different adjustment
positions. Thus, there is provided a first focusing lens 6100,
which is held in place in the main body 6031 by lens holding
assembly 6101. Thus, lens 6100 is fixed, and does not change
position relative to main body 6031. A second focusing lens 6102 is
held in place in the adjustment body 6028 buy holding assemblies
6103, 6104. Thus, lens 6102 is fixed, and does not change position
relative to the adjustment body 6028. Window 6105 is held in place
in the front end 6025 of the adjustment body 6028 by holding
assembly 6106. In this manner as the adjustment body 6028 is moved
in and out of the main body 6031 the distance, e.g., 6107b, 6107c,
6107d, between the two lens 6100, 6102 changes resulting in the
changing of the focal length of the optical system of the optics
package 6024. Thus, the optical system of optics package 6024 can
be viewed as a compound optical system.
[0217] In FIG. 24B the two lenses 6100, 6102 are at their closest
position, i.e., the distance 6107b is at its minimum. In FIG. 24C
the two lenses 6101, 6102 are at a middle distance, i.e., the
distance 6107c is at about the mid point between the minimum
distance and the maximum distance. In FIG. 24D the two lenses 6101,
6102 are at their furthest operational distance, i.e., the distance
6107d is the maximum distance that can operationally be active in
the optics assembly. (It should be noted that although the
adjustment body 6028 could be moved out a little further, e.g.,
there are a few threads remaining, to do so could compromise the
alignment of the lenses, and thus, could be disadvantages to the
performance of the optics package 6024.)
[0218] Turning to FIG. 25, there is shown a schematic of an
embodiment of an optical assembly for use in an optics package,
having a launch face 701 from a connector, ray trace lines 702 show
the laser beam exiting the face of the connector and traveling
through four lens, lens 710, lens 720, lens 730, lens 740. In this
embodiment lens 710 minimizes the aberrations for the lens 710-720
combination, which combination collimates the beam. Lens 730 and
740 are the focusing lenses, which focus the laser beam to a focal
point on focal plane 703. Lens 740 minimizes the spherical
aberrations of the 730-740 lens pair.
[0219] Differing types of lens may be used, for example in an
embodiment Lens 730 has a focal length of 500 mm and lens 740 has a
focal length of 500 mm, which provide for a focal length for the
optics assembly of 250 mm. The NA of the connector face is 0.22.
Lens 710 is a meniscus (f=200 mm). Lens 720 is a plano-convex
(f=200 mm). Lens 730 is a plano-convex (f=500 mm). Lens 740 is a
meniscus (f=500 mm). In another embodiment only one focusing lens
is used, lens 740. Lens 730 has been removed from the optical path.
As such, the focal length for the beam provided by this embodiment
is 500 mm. In a further embodiment, lens 730 has a 1,000 mm focus
and a diameter of 50.8 mm and lens 740 is not present in the
configuration, all other lens and positions remain unchanged,
providing for an optical assembly that has a focal length of 1,000
mm.
[0220] Turning to FIGS. 26A and 26B there is shown an embodiment of
a divergent, convergent lens optics assembly for providing a high
power laser beam for creating perforation holes having depths,
e.g., distances from the primary borehole, of greater than 10 feet,
greater than about 20 feet, greater than about 50 feet, and greater
than 100 feet.
[0221] FIG. 26A provides a side view of this optics assembly 800,
with respect to the longitudinal axis 870 of the tool. FIG. 26B
provides a front view of optics assembly 800 looking down the
longitudinal axis 870 of the tool. As best seen in FIG. 26A, where
there is shown a side schematic view of an optics assembly having a
fiber 810 with a connector 811 launch a beam into a collimating
lens 812. The collimating optic 812 directs the collimated laser
beam along beam path 813 toward reflective element 814, which is a
45.degree. mirror assembly. Reflective mirror 814 directs the
collimated laser beam along beam path 815 to diverging mirror 816.
Diverging mirror 816 directs the laser beam along diverging beam
path 817 where it strikes primary and long distance focusing mirror
818. Primary mirror focuses and directs the laser beam a long
perforating laser path 829 toward the casing, cement and/or
formation (not shown) to be perforated. Thus, the two mirrors 816,
818, have their reflective surfaces facing each other. The
diverging (or secondary) mirror 816 supports 819 are seen in FIG.
26B.
[0222] In an example of an embodiment of this optical assembly, the
fiber may have a core of about 200 .mu.m, and the NA of the
connector 811 distal face is 0.22. The beam launch assembly (fiber
810/connector 811) launches a high power laser beam, having 20 kW
of power in a pattern shown by the ray trace lines, to a secondary
mirror 816. The diverging mirror 816 is located 11 cm (as measured
along the total length of the beam path) from the launch or distal
face of the beam launch assembly. The secondary mirror has a
diameter of 2'' and a radius of curvature 143 cm. For distances of
about 100 feet the primary mirror 818 has a diameter of 18'' and a
radius of curvature of 135 cm. In this embodiment the primary
mirror is shaped, based upon the incoming beam profile, to provide
for a focal point 100 feet from the face the primary mirror. This
configuration can provided a very tight spot in the focal plain,
the spot having a diameter of 1.15 cm. Moving in either direction
from the focal plane, along the beam waist, for about 4 feet in
either direction (e.g., an 8 foot optimal cutting length of the
laser beam) the laser beam spot size is about 2 cm. For cutting
rock, it is preferable to have a spot size of about 3/4'' or less
(1.91 cm or less) in diameter (for laser beam having from about 10
to 40 kW). In an example of an embodiment during use, the diverging
mirror could have 2 kW/cm.sup.2 and the primary mirror could have
32 W/cm.sup.2 of laser power on their surfaces when performing a
laser perforation operation.
[0223] Generally, the location and position of the beam waist of
the laser beam can be varied and predetermined with respect to the
borehole surface, e.g., casing or formation, in which the
perforation hole is to be cut. By selecting the position of the
beam waist different laser material processes may take place and
different shape perforations may be obtained. Thus, and for
example, for forming deep penetrations into the formation, the
proximal end of the beam waist could be located at the borehole.
Many other relative positions of the focal point, the laser beam
optimum cutting portion, the beam waste, and the point where the
laser beam path initially intersects the borehole surface may be
used. Thus, for example, the focal point may be about 1 inch, about
2 inches, about 10 inches, about 15 inches, about 20 inches, or
more into (e.g., away from the casing or borehole surface) or
within the formation.
[0224] The laser beam waist in many applications is preferably in
the area of the maximum depth of the cut. In this manner the hole
opens up toward the face (front surface) of the borehole, which
further helps the molten material to flow from, or be removed from,
the perforation hole. Thus turning to FIG. 27 there is shown a
casing 201 in a borehole 203 having a front or inner face 202.
Between the casing 201 and the formation 206 is cement 205. A laser
beam 210 that is launched from a laser perforation tool (not shown
in this figure) travels along laser beam path 211 in a
predetermined beam profile, which is provided by the laser optical
assembly in the tool. The predetermined beam profile provides for a
beam waist 212, which is positioned deep within the formation 206
behind the casing 201 and cement 205. Thus, the perforation hole
may be about 5 inches, about 10 inches, about 15 inches, about 20
inches or more, or deeper into the formation. Additionally, damaged
areas, that are typically present when explosives are used, such as
loose rock and perforation debris along the bottom of the hole and
a damaged zone extending annularly around the hole, preferably are
not present in the laser perforation. Further this preferred
positioning of the beam waist, deep within the formation, may also
provide higher rates of penetration.
[0225] Turning to FIG. 28A through 28C there are provided side
cross-sectional schematic snap shot views of an embodiment of a
laser operation forming a hole, or perforation, into a formation.
Thus, turning to FIG. 28A, in the beginning of the operation the
laser tool 3000 is firing a laser beam 3027 along laser beam path
3026, and specifically along section 3026a of the beam path. Beam
path section 3026a is in the wellbore free space 3060, this
distance may be essential zero, but is shown as greater for the
purpose of illustrating the process. Note, that wellbore free space
refers to the fact that the laser has been launched from its last
optical element and is no longer traveling in an optical fiber, a
lens, a window or other optical element. This environment may be
anything but free from fluids; and, if wellbore fluids are present
other laser cutting and fluid management techniques can be used if
needed. The laser beam path 3026 has a 16.degree. beam path angle
3066 formed with horizontal line 3065. The laser beam path 3026 and
the laser beam 3027 traveling along that beam path intersect the
borehole face 3051 of the formation 3050 at spot 3052. In this
embodiment the proximal end of the laser beam waist section is
located at spot 3052. The hole or perforation 3080 is beginning to
form, as it can be seen that the bottom, or distal, surface 3081 of
the hole 3080 is below surface 3051, along beam path 3026b, and
within the target material 3050. As can be seen from this figure
the hole 3080 is forming with a downward slope from the bottom of
the hole 3081 to the hole opening 3083. The molten target material
3082 that has flowed from the hole 3080 cools and accumulates below
the hole opening 3083.
[0226] Turning to FIG. 28B the hole 3081 has become longer,
advancing deeper into the formation 3050. In general, the hole
advances along beam path 3026a. Thus, the bottom 3081 of the hole
is on the beam path 3026b and deeper within the formation, e.g.,
further from the opening 3083, than it was in FIG. 28A.
[0227] Turning now to FIG. 28C the hole 3081 has been substantially
advanced to the extent that the bottom of the hole is no longer
visible in the figure. The amount of molten material 3082 that has
flowed from the hole 3081 has continued to grow. In this embodiment
the length of hole 3082 is substantially longer than the length of
the beam waist. The diameter, or cross sectional size of the hole,
however does not increase as might be expected in the area distal
to the beam waist. Instead, the diameter remains constant, or may
even slightly decrease. It is theorized, although not being bound
by this theory, that this effect occurs because the optical
properties of the hole, and in particular the molten and
semi-molten inner surfaces of the hole, are such that they prevent
the laser beam from expanding after it is past, i.e., distal to,
the beam waist. Further, and again not being bound by this theory,
the inner surfaces may absorb the expanding portions of the laser
beam after passing through the waist, the inner surfaces may
reflect the expanding portions of the laser beam, in effect
creating a light pipe within the hole, or the overall conditions
within the hole may create a waive guide, and combinations and
variations of these. Thus, the depth or length of the hole can be
substantially, and potentially may orders of magnitude greater than
the length of the beam waist.
[0228] While an upward beam angle is used in the illustrative
process of FIGS. 28A to 28C, perforations that are essentially
horizontal or that have beam angles that are below horizontal,
i.e., sloping downward from the hole opening or vertically downward
from the hole opening, may also be made. In upward beam angle
operations the need for a fluid assist to clear the perforation
hole as it is advanced is greatly reduced, if not entirely
eliminated. The perforation hole can advance without the need for
any fluid assist, e.g., air or water to remove the molten or laser
effected material from the hole.
[0229] A laser beam profile in which the laser beam energy is
diverging, e.g., more energy is to the outside of the beam than in
the center, may be used to make perforations that are below
horizontal, including down. The laser beam having this profile
creates a surface on the perforation side wall that redirects,
e.g., has a channeling or focusing effect, some of the laser beams
energy to the center of the beam pattern or spot on the bottom,
e.g., far end, of the perforation hole.
[0230] The laser beam profile and energy delivery pattern may be
used to create a modified surface, and/or structure at the point,
or in the general area, where the perforation joins to the
borehole, to strengthen the borehole in that area, which may
provide additional benefits, for example, when performing hydraulic
fracturing.
[0231] Additionally, the use of lasers, in comparison to explosive
perforators and other perforation techniques that create shock
waves, allows for the use down hole during perforating operations
of shock sensitive instruments that provide the ability for real
time, essentially real time, and monitoring with out the need to
trip out and in, during perforating operations, as well as during
fracturing operations. Thus, laser perforating tools and laser
fracturing assemblies can included, or otherwise have associated
with them shock sensitive instruments, such as for the precise
measurement of flow, pressure or both, which instruments could not,
survive, or reliably survive, down hole in the presence of
conventional perforating operations.
[0232] Turning to FIG. 29 there is provided a schematic showing an
embodiment of a laser operation in which the distal end of the beam
waist is positioned away from the work surface, e.g., borehole
surface, of the target material, e.g., formation. The laser tool
4000 is firing a laser beam 4027 along laser beam path 4026, which
may be considered as having two section 4026a and 4026b. Beam path
section 4026a is in wellbore free space 4060, this distance may be
essential zero, but is shown a greater for the purpose of
illustrating the process, and beam path 4026b is within the target
material 4050. Note, that wellbore free space refers to the fact
that the laser has been launched from its last optical element and
is no longer traveling in a lens or window. This environment may be
anything but free from fluids; and, if wellbore fluids are present
other fluid management techniques may be utilized. The laser beam
path 4026 has a 22.degree. beam path angle 4066 formed with
horizontal line 4065. The laser beam path 4026 and the laser beam
4027 traveling along that beam path intersect the surface 4051 of
target material 4050 at location 4052. In this embodiment the
distal end 4064b of the laser beam waist section is not on location
4052 and is located away from surface 4051. In this embodiment the
hole or perforation 4080 forms but then reaches a point where the
bottom of the hole 4081 will not advance any further along the beam
path 4026b, e.g., the hole stops forming and will not advance any
deeper into the target material 4050. Further, unlike the operation
of the embodiment in FIGS. 28A to 28C, the hole 4080 does not have
a constant or narrowing diameter as one looks from the opening 4083
to the bottom 4081 of the hole 4080. The molten target material
4082 that has flowed from the hole 4080 cools and accumulates below
the hole opening 4083. Based upon the laser beam power and other
properties, this embodiment provides the ability to have precise
and predetermined depth and shaped holes, in the target material
and to do so without the need for measuring or monitoring devices.
Once the predetermined depth is achieved, and the advancement
process has stopped, regardless of how much longer the laser is
fired the hole will not advance and the depth will not increase.
Thus, the predetermined depth is essentially a time independent
depth. This essentially automatic and predetermined stopping of the
hole's advancement provides the ability to have cuts of automatic
and predetermined depths, and well as, to section or otherwise
remove the face of a rock formation at a predetermined depth in an
essentially automatic manner.
[0233] Oriented perforations have long been desired by the art, and
if properly accomplished viewed as a way to enhance the production
from a well. The need to have oriented perforations and the
benefits, if such oriented perforations could be obtained and
optimized, are addressed and discussed in the art, such as for
example, J. Almaguer, Orienting Perforation in the Right Direction,
pp 16-31 (Oilfield Review, Spring 2002), US Patent Publication No.
2013/0032347; US Patent Publication No. 2005/0194146; US Patent
Publication No. 2010/0269676; and U.S. Pat. No. 8,127,848, the
entire disclosures of each of which are incorporated herein by
reference. While espousing the benefits of oriented perforations
these disclosures, and the art in general, has been unable to
obtain or provide such benefits, and to do so on a consistent
basis, because of the inherent limitations in current explosive
based perforating devices and technologies. As can be seen from the
above, by way of example, the art is moving toward more complex
explosive configurations; but even these complex configurations are
still unduly limited, costly, dangerous, time consuming to
configure, and failing in many aspects when viewed against the
present laser fracturing and perforating apparatus and methods and
their capabilities.
[0234] Laser based oriented perforating minimizes flow restrictions
and friction pressures during fracturing. It can provide wider
fractures that permit, among other things, the use of larger sizes
and higher concentrations of proppants along with lower viscosity,
less damaging fluids to improve fracture conductivity. In weakly
consolidated reservoirs or formations with large stress contrasts,
the laser fracturing assemblies provide the ability to consistently
obtain properly aligned perforations, which will maximize
perforation-tunnel stability in the formation to provide several
advantages, including for example mitigation of sand
production.
[0235] In general, in determining a preferred laser hydraulic
fracturing procedure and laser perforation geometry or volumetric
removal, the maximum and minimum horizontal stresses and vertical
stress from overburden can be viewed among other things as
describing the in-situ stress conditions in oil and gas
reservoirs.
[0236] Hydraulic fractures initiate and propagate along a preferred
fracture plane ("PFP"), which is the path of least resistance
resulting from differences in direction and magnitude of formation
stresses. In most cases, stress is greatest in the vertical
direction, so the PFP is vertical and lies in the direction of the
next greatest stress, e.g., the maximum horizontal stress. Thus,
perforations that are not aligned with the maximum stress tend to
produce complex flow paths near a wellbore during hydraulic
fracturing treatments. Fluids and proppants must exit well bores,
and then turn in the formation to align with the PFP. This
"tortuosity" causes additional friction and pressure drops that
increase pumping horsepower requirements and limit fracture width,
which can result in premature screenout from proppant bridging and,
consequently, less than optimal stimulation treatments. The present
laser based fracturing, hydraulic fracturing, perforating and
stimulation systems and methods minimize, reduce and preferably
eliminate these undesirable results, and thus, can greatly reduce,
if not eliminate tortuosity in the near, and potentially more
distance well bore environment.
[0237] The laser systems and apparatus of the present inventions
can provide for fractures and hydraulic fractures that propagate in
the direction of maximum horizontal stress ("Sh"). When
perforations are not oriented with the maximum stress, fractures
travel from the tunnel base or tip around casing and cement, or
turn out in the formation to align with the PFP. This realignment
creates complex near-well bore flow paths, including multiple
fracture initiation points; competing fractures possibly continuing
far afield; micro-annulus pathways with pinch-point restrictions;
and fracture wings that are curved or poorly aligned with the
wellbore and perforations. These undesirable and costly down hole
conditions can be reduced, mitigated and preferably eliminated with
the present laser fracturing and perforating systems and
methods.
EXAMPLES
[0238] The following examples are provided to illustrate various
laser hydraulic fracturing operations of the present inventions.
These examples are for illustrative purposes, and should not be
viewed as, and do not otherwise limit the scope of the present
inventions.
Example 1
[0239] Using the laser perforating tool a predetermined and
oriented volumetric removal of casing and formation is provided
down hole. The predetermined volumetric and oriented removal is
oriented with the PFP. In this manner the laser volumetric removal
allows hydraulic fracturing conditions that generate optimal
fracture initiation, fracture propagation, proppant placement and
final fracture geometry (e.g., width, length, height and
conductivity) and minimize fluid flow right at the wellbore.
Example 2
[0240] In a weakly consolidated formation the laser fracturing
assembly of the embodiment of FIG. 9 is used to minimize formation
failure at the perforations and thus minimize sand production.
Further, the laser volumetric removal, e.g., the perforation
"tunnels," minimize collapse as reservoir rock supports more
overburden as hydrocarbons are produced and pore pressure
decreases. The laser volumetric removals are predetermined to be in
the most stable directions with minimum stress contrasts to
mitigate sand production by reducing flowing pressure drops,
changing flow configurations and creating more even stress
distributions around the well bore.
Example 3
[0241] Using the laser hydraulic fracturing assembly of the
embodiment of FIG. 9 a predetermined and oriented volumetric
removal of casing and formation is provided down hole. The
predetermined volumetric and oriented removal is oriented with the
PFP. After an initial flow of a pad of fracturing fluid, the laser
cutting operation is adjusted, optimized and continued. In this
manner the laser volumetric removal is optimized, based upon real
time hydraulic fracturing data, to allow hydraulic fracturing
conditions that generate optimal fracture initiation, fracture
propagation, proppant placement and final fracture geometry (e.g.,
width, length, height and conductivity) and minimize fluid flow
right at the wellbore.
Example 4
[0242] In a well containing multiple tubulars a laser perforation
is performed. The laser perforating device is located in the well
bore, in the tubular to be perforated. The laser head is aimed such
that the laser beam path does not contact the other tubular in the
well. This orientation can be accomplished by mechanical means or
by sensors. Preferably, a lower power laser beam is used as sensing
device or laser range finder to confirm that the laser beam path is
properly directed. The laser perforation is then commenced.
Example 5
[0243] Turning to FIG. 31 there is shown a section of a well bore
casing 371 in a formation 377. The casing 371 has an axis 372 that
is at an angle 373 from vertical 370. The casing 371 is located in
formation 377, which has a preferred fracture plane 374 of a
hydrocarbon containing formation, which intersects the casing 371.
The fracture plane 374 has an axis 375, which forms an angle 376
between the fracture plane axis 375 and the casing axis 372. The
angle 378 of the fracture plane from vertical 370 is less than the
angle 373 of the casing from vertical 370. It being understood that
the angle of the fracture plane from vertical may be greater than,
equal to, or less than the angle of the casing from vertical. The
orientations of these axes may be at different orientations with
respect to the vertical axis, e.g., if viewed as positions on the
face of a clock, they may be at different locations on the face of
the clock. A custom laser perforation pattern along the axis 375 of
the preferred fracture plane 374 is delivered and the formation is
hydraulically fractured through those laser perforations.
Example 6
[0244] Turning to FIG. 31 there is shown a section of a well bore
casing 371 in a formation 377. The casing 371 has an axis 372 that
is at an angle 373 from vertical 370. The casing 371 is located in
formation 377, which has a preferred fracture plane 374 of a
hydrocarbon containing formation, which intersects the casing 371.
The fracture plane 374 has an axis 375, which forms an angle 376
between the fracture plane axis 375 and the casing axis 372. The
angle 378 of the fracture plane from vertical 370 is less than the
angle 373 of the casing from vertical 370. It being understood that
the angle of the fracture plane from vertical may be greater than,
equal to, or less than the angle of the casing from vertical. The
orientations of these axes may be at different orientations with
respect to the vertical axis, e.g., if viewed as positions on the
face of a clock, they may be at different locations on the face of
the clock. Using a laser fracturing assembly of the embodiment of
FIG. 2 a preliminary laser perforation pattern is delivered into
the formation. A mini-hydraulic fracture is then performed and the
pressure and flow characteristics of that fracture are evaluated.
From this information, it is determined that significant tortuosity
is present. The angle and direction of the laser perforation is
adjusted and a second preliminary laser perforation pattern is
delivered into the formation. A second mini-hydraulic fracture is
then performed and the pressure and flow characteristics of that
fracture are evaluated. This procedure of laser perforation,
mini-fracture and adjustment is continued until the tortuosity is
significantly reduced, and preferably eliminated, by the deliver of
the laser perforations and hydraulic fracturing along the axis 375
of the preferred fracture plane 374.
Example 7
[0245] Turning to FIG. 32 there is shown a section of a well bore
casing 381 in a formation 387. The casing 381 has an axis 382 that
is at an angle 383 from vertical 380. The casing 381 is located in
formation 387, which has a preferred fracture plane 384 of a
hydrocarbon containing formation, which intersects the casing 381.
The fracture plane 384 has an axis 385, which forms an angle 386
between the fracture plane axis 385 and the casing axis 382. The
angle 388 of the fracture plane from vertical 380 is less than the
angle 383 of the casing from vertical 380. It being understood that
the angle of the fracture plane from vertical may be greater than,
equal to, or less than the angle of the casing from vertical. The
orientations of these axes may be at different orientations with
respect to the vertical axis, e.g., if viewed as positions on the
face of a clock, they may be at different locations on the face of
the clock. A custom laser perforation pattern essentially along the
axis 385 of the preferred fracture plane 384 is delivered and the
formation is hydraulically fractured through those laser
perforations.
Example 8
[0246] Turning to FIG. 32 there is shown a section of a well bore
casing 381 in a formation 387. The casing 381 has an axis 382 that
is at an angle 383 from vertical 380. The casing 381 is located in
formation 387, which has a preferred fracture plane 384 of a
hydrocarbon containing formation, which intersects the casing 381.
The fracture plane 384 has an axis 385, which forms an angle 386
between the fracture plane axis 385 and the casing axis 382. The
angle 388 of the fracture plane from vertical 380 is less than the
angle 383 of the casing from vertical 380. It being understood that
the angle of the fracture plane from vertical may be greater than,
equal to, or less than the angle of the casing from vertical. The
orientations of these axes may be at different orientations with
respect to the vertical axis, e.g., if viewed as positions on the
face of a clock, they may be at different locations on the face of
the clock. Using a laser fracturing assembly of the embodiment of
FIG. 9 a preliminary laser perforation pattern is delivered into
the formation. A mini-hydraulic fracture is then performed and the
pressure and flow characteristics of that fracture are evaluated.
From this information, it is determined that significant tortuosity
is present. The angle and direction of the laser perforation is
adjusted and a second preliminary laser perforation pattern is
delivered into the formation. A second mini-hydraulic fracture is
then performed and the pressure and flow characteristics of that
fracture are evaluated. This procedure of laser perforation,
mini-fracture and adjustment is continued until the tortuosity is
significantly reduced, and preferably eliminated, by the deliver of
the laser perforations and hydraulic fracturing along the axis 385
of the preferred fracture plane 384.
Example 9
[0247] The critical path of drilling a well is reduced, and the
measured depth of the well is reduced by the ability to have laser
hydraulic fracturing. Turning to FIG. 33 there is shown a first
borehole 391 below the surface 390 of the earth. The borehole 391
follows a path that is designed to intersect a hydrocarbon
containing reservoir, having a preferred fracture plane 393, at an
angle that accommodates the inherent limitations in explosive based
perforations. Because of the greater flexibility, control and
predictability of laser perforation and laser hydraulic fracturing
the borehole can follow an entirely different path, and can be
drilled in a more direct path 392, reducing the critical path to
completing the well, and reducing the total measured depth of the
well. The laser perforation can be directed to create perforation
along the preferred fracture plane of the formation from
essentially any angle that the borehole may intersect that
plane.
Example 10
[0248] In a carbonate oil reservoir as the formation has been
depleted pay zones having characteristics of a porosity of 4.8% and
a permeability of 2 mD are present. A well bore is drilled, and
custom laser perforations are made and the well is hydraulically
fractured.
Example 11
[0249] In a shale gas reservoir the formation has porosity and
permeability of about 3.5% and 300 nD (nanodarcies). A horizontal
well is drilled having a TVD of 8,800 feet and a MD of 16,800 feet.
The well is laser hydraulically fractured with 5 stages of adaptive
laser perforations, to significantly reduce any near well bore
tortuosity. After the laser pattern is optimized, and completed,
the well is fractured with a a slick water hydraulic
fracture--about 2,600 gal./min., and about 2,000 tons of sand per
740,000 gals per stage.
Example 12
[0250] In a shale reservoir the formation has a porosity and
permeability of about 3 to 5% and <500 nD. A horizontal well is
drilled having a TVD of 5,500 feet and a MD of 15,700 feet. The
well is laser hydraulically fractured with 5 stages of custom
volumetric removal laser perforations, using the pattern of the
embodiment of FIG. 8. The well is fractured with a slick water
hydraulic fracture--about 3,500 gal./min., and about 3,000 tons of
sand per 7,000,000 gals for all stages.
Example 13
[0251] A oil field for a shale gas reservoir having a porosity and
permeability of about 4.5% and 350 nD is planned. A laser hydraulic
fracturing model is developed for the production of hydrocarbons
from the field. Well placement is increased, and total number of
wells is reduced, when compared to placement and numbers by using
conventional explosive perforation and fracturing techniques.
Example 14
[0252] A testing mini-fracture is performed on a tight shale gas
formation having a horizontal borehole with a TVD of 10,000 feet
and a MD of 15,000 feet. A laser perforating tool is positioned in
the borehole and a series of laser perforation at preset diameters
and about 3 inches deep spaced at 12 inch intervals. The diameters
of the holes are varied based upon the radial position of the hole,
e.g., 0.degree., 15.degree., 30.degree., 45.degree., etc., each
have a unique diameter. The angle of the laser beam path with
respect to the axis of the borehole may also be varied to determine
the PFP. In this manner a series of mini-fractures for each radial
position can be performed, with the perforations being selectively
plugged with balls or sealed using the welding capability of the
laser, to make certain that known data is being obtained during a
particular mini-fracture. In this manner a laser perforation
pattern can be devised that will minimize, and preferably reduce
near well bore tortuosity.
Example 15
[0253] A testing mini-fracture is performed on a tight shale gas
formation having an essentially vertical borehole with a TVD of
15,000 feet and a MD of 16,000 feet. A laser perforating tool is
positioned in the borehole and a series of laser perforation at
preset diameters and about 3 inches deep spaced at 12 inch
intervals. The diameters of the holes are varied based upon the
radial position of the hole, e.g., 0.degree., 15.degree.,
30.degree., 45.degree., etc., each have a unique diameter. The
angle of the laser beam path with respect to the axis of the
borehole may also be varied to determined the PFP. In this manner a
series of mini-fractures for each radial position can be performed,
with the perforations being selectively plugged with balls or
sealed using the welding capability of the laser, to make certain
that known data is being obtained during a particular
mini-fracture. In this manner a laser perforation pattern can be
devised that will minimize, and preferably reduce near well bore
tortuosity.
Example 16
[0254] In laser perforating procedure a series of about 50 laser
perforations are made in the casing and into the formation,
creating a series of 50 volumetric removals having essentially a
cylindrical geometric shape. The diameter of each of the 50 laser
created holes, has a diameter of "x", and these diameters very
consistent, e.g., having a variation in diameter of less than about
90%, less than about 95%, less than about 98% and preferably less
than about 99%.
Example 17
[0255] In a laser hydraulic fracturing procedure, an adaptive laser
perforating method is employed to develop an optimized laser
perforating pattern to minimize near well bore tortuosity. The
laser pattern is delivered to the well, and substantially all of
the laser perforations, are operable, i.e., they function as
channels for the flow of fracturing fluid into the preferred
fracturing plane of the formation.
Example 18a
[0256] In well bore that has been fractured through perforations is
in need of being refractured. The perforations are approximately
1/4 inch wide and 2 feet long. A down hole laser patching and
welding process, as disclosed and taught in Ser. No. 61/798,875,
the entire disclosure of which is incorporated herein by reference,
is used to fill and plug the perforation slits with metal. The
casing is then reperforated and refractured.
Example 18b
[0257] In well bore that has been fractured through perforations is
in need of being refractured. The perforations are approximately
1/4 inch wide and 2 feet long. A down hole laser patching and
welding process, as disclosed and taught in Ser. No. 61/798,875,
the entire disclosure of which is incorporated herein by reference,
is used to fill and plug the perforation slits with metal. The
casing is then reperforated with the downhole laser and
refractured.
Example 19
[0258] In a shale reservoir the formation has a porosity and
permeability of about 3 to 5% and <500 nD. A horizontal well is
drilled having a TVD of 5,500 feet and a MD of 15,700 feet. The
well is laser hydraulically fractured with 5 stages of custom
volumetric removal laser perforations, using the pattern of the
embodiment of FIG. 9. Each stage has two disc cut into the 5''
casing present in the well. These volumetric removal discs are
1/4'' in length and remove material into the formation to a depth
of about 4'' beyond the outer casing wall. Thus the volumetrically
removed discs have a length of about 1/4'' and a radius of about
61/2''. The well is fractured with a fracturing fluid using
proppant.
Example 20
[0259] In a shale reservoir the formation has a porosity and
permeability of about 5% and <700 nD. A horizontal well is
drilled having a TVD of 5,000 feet and a MD of 15,000 feet. The
well is laser hydraulically fractured with 3 stages of custom
volumetric removal laser perforations, using a volumetric removal
pattern that creates perforation holes that are cylindrical; and
then hydraulically fractured. The lip (configuration of the opening
with respect to the casing and cement) of the perforations and
diameter of the perforation is matched and predetermined for the
particular type of proppant being used. In this manner, screen
outs, abrasion, plugging and burrs are reduced, and preferably
eliminated.
Example 21a
[0260] Turning to FIG. 35 there is provided a cross sectional view
of a section of a formation 3500 (it being understood that the
section is part of the earth below the surface). The formation 3500
has a zone of interest 3501, which may be a pay zone containing
hydrocarbons. The formation 3500 has a maximum direction of stress
(SH), which is shown by arrows 3506, and is a preferred fracture
plane (PFP). The formation 3500 has a minimum direction of stress
(Sh), which is shown by arrows 3507. The formation 3500 has a
borehole 3502, which has a borehole axis 3503, extends through the
formation 3500 and through the zone of interest 3501. The axis 3503
is at an angle and orientation with the zone of interest 3501 and
the PFP 3506. Laser perforations 3504 extend out from the borehole
in the PFP 3506 and provide a custom laser perforation geometry
that enhances the flow of hydrocarbons into the borehole. The laser
perforations 3504 are in the PFP 3506, follow the PFP 3506, and are
parallel with the PFP 3506.
Example 21b
[0261] Turning to FIG. 35 the zone of interest 3501 is
hydraulically fractured by flowing under pressure fracturing fluid
through the perforations 3504 into the zone of interest 3501, which
fractures the zone of interest.
Example 22a
[0262] Turning to FIG. 36 there is provided a cross sectional view
of a section of a formation 3600 (it being understood that the
section is part of the earth below the surface). The formation 3600
has a zone of interest 3601, which may be a pay zone containing
hydrocarbons. The formation 3600 has a maximum direction of stress
(SH), which is shown by arrows 3606, and is a preferred fracture
plane (PFP). The formation 3600 has a minimum direction of stress
(Sh), which is shown by arrows 3607. The formation 3600 has a
borehole 3602, which has a borehole axis 3603, extends through the
formation 3600 and through the zone of interest 3601. The axis 3603
is at an angle and orientation with the zone of interest 3601 and
the PFP 3606. Laser perforations 3604 extend out from the borehole
in the PFP 3606 and provide a custom laser perforation geometry
that enhances the flow of hydrocarbons into the borehole. The laser
perforations 3604 are in the PFP 3606.
Example 22b
[0263] Turning to FIG. 36 the zone of interest 3601 is
hydraulically fractured by flowing under pressure fracturing fluid
through the perforations 3604 into the zone of interest 3601, which
fractures the zone of interest.
Example 23a
[0264] Turning to FIG. 37 there is provided a cross sectional view
of a section of a formation 3700 (it being understood that the
section is part of the earth below the surface). The formation 3700
has a zone of interest 3701, which may be a pay zone containing
hydrocarbons. The formation 3700 has a maximum direction of stress
(SH), which is shown by arrows 3706, and is a preferred fracture
plane (PFP). The formation 3700 has a minimum direction of stress
(Sh), which is shown by arrows 3707. The formation 3700 has a
borehole 3702, which branches into two boreholes 3702a, 3702b each
having has a borehole axis 3703a, 3703b, these two boreholes 3702a,
3702b, extend through the formation 3700 and through the zone of
interest 3701. The axes 3703a, 3703b, are at an angle and
orientation with the zone of interest 3701 and the PFP 3706. Laser
perforations 3704a, 3704b, extend out from the boreholes 3702a,
3702b, in the PFP 3706 and provide a custom laser perforation
geometry that enhances the flow of hydrocarbons into the borehole.
The laser perforations 3704a, 3704b follow the PFP 3506.
Example 23b
[0265] Turning to FIG. 37 the zone of interest 3701 is
hydraulically fractured by flowing under pressure fracturing fluid
through the perforations 3704a, 3704b, into the zone of interest
3701, which fractures the zone of interest.
[0266] In addition to the foregoing examples, laser perforating and
fracturing systems and tools and operations may find considerable
uses in other unconventional or difficult to produce from
formations. For example, in shales for unconventional extraction of
gas and oil there is no permeability. The current operations to
access this rock and make it productive are to drill a 6 to 12 inch
diameter borehole, thousands of feet long with a mechanical rig and
bit, and then perforate on the order of inches using explosives.
Once the perforations are formed thousands of gallons of high
pressure fluid and proppant are used to open the pores to increase
permeability.
[0267] The high power laser perforating tools can greatly improve
on the conventional operation by creating a custom geometry (e.g.
shape, length, entrance area, thickness) with a laser. This custom
geometry can stem off a main borehole in any orientation and
direction, which in turn will initiate a fracture that is more
productive than existing conventional methods, by exposing more
rock and positioning the fractures in optimum stress planes.
[0268] Generally, fracturing in rocks at depth is suppressed by the
confining pressure, from the weight of the rocks and earth above.
The force of the overlying rocks is particularly suppressive of
fracturing in the situation of tensile fractures, e.g., Mode 1
fractures. These fractures require the walls of the fracture to
move apart, working against this confining pressure. Hydraulic
fracturing or fracing is used to increase the fluid communication
between the borehole and the formation. Thus, it can restore,
maintain, and increase the rate at which fluids, such as petroleum,
water, and natural gas are produced from reservoirs in formations.
Thus, it has long been desirable to create conductive fractures in
the rock, which can be pivotal to extract gas from shale reservoirs
because of the extremely low natural permeability of shale, which
is measured in the microdarcy to nanodarcy ranges. These fractures
provide a conductive path connecting a larger volume of the
reservoir to the borehole.
[0269] The custom geometry that can be created with laser
perforating can provide enhanced, more predictable, and more
controllable predetermined conductive paths that result from
hydraulic fracturing. Thus, the laser perforation custom geometry
can increase the efficiency of hydraulic fracturing and hydrocarbon
production from a well.
[0270] The fluids used to perform hydraulic fracture can range from
very simple, e.g., water, to very complex. Additionally, these
fluids, e.g., fracing fluids or fracturing fluids, typically carry
with them proppants; but not in all cases, e.g., when fracing
carbonate formations with acids. Proppants are small particles,
e.g., grains of sand, aluminum shot, sintered bauxite, ceramic
beads, resin coated sand or ceramics, that are flowed into the
fractures and hold, e.g., "prop" or hold open the fractures when
the pressure of the fracturing fluid is reduced and the fluid is
removed to allow the resource, e.g., hydrocarbons, to flow into the
well. In this manner the proppants hold open the fractures, keeping
the channels open so that the hydrocarbons can more readily flow
into the well. Additionally, the fractures greatly increase the
surface area from which the hydrocarbons can flow into the well.
Typically fracturing fluids, used for example in shale gas
stimulations, consist primarily of water but also have other
materials in them. The number of other materials, e.g., chemical
additives used in a typical fracture treatment varies depending on
the conditions of the specific well being fractured. Generally, for
shale gas, a typical fracture treatment will use very low
concentrations of from about 2 to about 15 additives. Each
component serves a specific, engineered purpose to meet anticipated
well and formation conditions.
[0271] Generally the he predominant fluids being used for fracture
treatments in the shale plays are water-based fracturing fluids
mixed with friction-reducing additives, e.g., slick water, or slick
water fracs. Overall the concentration of additives in most slick
water fracturing fluids is generally about 0.5% to 2% with water
making up 98% to 99.5%. The addition of friction reducers allows
fracturing fluids and proppant to be pumped to the target zone at a
higher rate and reduced pressure than if water alone were used.
[0272] In addition to friction reducers, other such additives may
be, for example: biocides to prevent microorganism growth and to
reduce biofouling of the fractures; oxygen scavengers and other
stabilizers to prevent corrosion of metal pipes; and acids that are
used to remove drilling mud damage within the near-wellbore.
[0273] Further these chemicals and additives could be one or more
of the following, and may have the following uses or address the
following needs: diluted Acid (.apprxeq.15%), e.g., hydrochloric
acid or muriatic acid, which may help dissolve minerals and
initiate cracks in the rock; a biocide, e.g., Glutaraldehyde, which
eliminates bacteria in the water that produce corrosive byproducts;
a breaker, e.g., ammonium persulfate, which allows a delayed break
down of the gel polymer chains; a corrosion inhibitor, e.g.,
N,n-dimethyl formamide, which prevents the corrosion of pipes and
equipment; a crosslinker, e.g., borate salts, which maintains fluid
viscosity as temperature increases; a friction reducer; e.g.,
polyacrylamide or mineral oil, which minimizes friction between the
fluid and the pipe; guar gum or hydroxyethyl cellulose, which
thickens the water in order to help suspend the proppant; an iron
control, e.g., citric acid, which prevents precipitation of metal
oxides; potassium chloride, which creates a brine carrier fluid; an
oxygen scavenger, e.g., ammonium bisulfite, which removes oxygen
from the water to reduce corrosion; a pH adjuster or buffering
agent, e.g., sodium or potassium carbonate, which helps to maintain
the effectiveness of other additives, such as, e.g., the
crosslinker; scale inhibitor, e.g., ethylene glycol, which prevents
scale deposits in pipes and equipment; and a surfactant, e.g.,
isopropanol, which is used to increase the viscosity of the
fracture fluid.
[0274] The ability to cut custom and smooth perforation opens, as
well as custom geometries, e.g., cuts into and following the PFP,
provides the ability to reduce the dependency, need for, and thus
the amount of chemicals used in a fracturing fluid. Thus, in a
slick water fractures, but of more importance in the more
chemically complex fracturing jobs, the use of laser perforation
and laser fracturing can reduce, and preferably greatly reduce, the
amount, the number and both, of the chemical additives used, or
that are needed in the fracing fluid for a particular fracturing
job.
[0275] Laser perforated custom geometries for hydraulic fracturing
have many advantages in all well types, and particularly have
advantages in horizontal drilling, which involves wellbores where
the borehole is completed as a "lateral" that extends parallel to
the hydrocarbon containing rock layer. For example, lateral
boreholes can extend 1,500 to 5,000 feet (460 to 1,500 m) in the
Barnett Shale basin in Texas, and up to 10,000 feet (3,000 m) in
the Bakken formation in North Dakota. In contrast, a vertical well
only accesses the thickness of the rock layer, typically 50-300
feet (15-91 m). Additionally, mechanical drilling, however,
typically causes damage to the pore space, e.g., formation
structure, at the near well bore area, including at the wellbore
wall, reducing the permeability at and near the wellbore. This
reduces flow into the borehole from the surrounding rock formation,
and partially seals off the borehole from the surrounding rock.
Custom geometries, from the laser perforation, enable hydraulic
fracturing in these wells to restore and potentially increase
permeability and the productivity of the well.
[0276] Thus, the laser perforating tools, and laser energy
distribution patterns, which can provide custom geometries for
hydraulically fracturing operations, have the potential to greatly
increase hydrocarbon production, especially form unconventional
sources.
[0277] Downhole tractors and other types of driving or motive
devices may be used with the laser tools. These devices can be used
to advance the laser tool to a specific location where a laser
process, e.g., a laser cut is needed, or they can be used to move
the tool, and thus the laser head and beam path to deliver a
particular pattern to make a particular cut. It being understood
that the arrangement and spacing of these components in the tools
and systems may be changed, and that additional and different
components may be used or substituted in, for example, such as a
MWD/LWD section.
[0278] The high power laser fluid jets, laser heads and laser
delivery assemblies disclosed and taught in US Patent Application
Publ. No. 2012/0074110, the entire disclosure of which is
incorporated herein by reference, may be used with, in, for, and as
a part of the laser perforating tools, systems and methods of the
present inventions. Laser fluid jets, and their laser tools and
systems may provide for the creation of perforations in the
borehole that can further be part of, or used in conjunction with,
recovery activities such as geothermal wells, EGS (enhanced
geothermal system, or engineered geothermal system), hydraulic
fracturing, micro-fracturing, recovery of hydrocarbons from shale
and any other rock formations, oriented perforation, oriented
fracturing and predetermined perforation patterns. Moreover, the
present inventions provide the ability to have precise, varied and
predetermined shapes for perforations, and to do so volumetrically,
in all dimensions, i.e. length, width, depth and angle with respect
to the borehole.
[0279] Thus, the present inventions provide for greater flexibility
in determining the shape and location of perforations, than the
conical perforation shapes that are typically formed by explosives
or the holes created by pumping solids in a stream of fluid at high
pressure. For example, perforations in the geometric shape of
slots, squares, rectangles, ellipse, and polygons that do not
diminish in area as the perforation extend into the formation, that
expand in area as the perforation extends into the formation, or
that decrease in area, e.g., taper, as the perforation extends into
the formation are envisioned. Further, the locations of the
perforation along the borehole can be adjusted and varied while the
laser tool is downhole; and, as logging, formation, flow, pressure
and measuring data is received. Thus, the present inventions
provide for the ability to precisely position additional
perforations without the need to remove the perforation tool from
the borehole.
[0280] Accordingly, there is provided a procedure where a downhole
tool having associated with it a logging and/or measuring tool and
a fluid laser jet tool is inserting into a borehole. The laser tool
is located in a desired position in the borehole (based upon
real-time data, based upon data previously obtained, or a
combination of both types of data) and a first predetermined
pattern of perforations is created in that location. After the
creation of this first set of perforations additional data from the
borehole is obtained, without the removal of the laser tool, and
based upon such additional data, a second pattern for additional
perforations is determined (different shapes or particular shapes
may also be determined) and those perforations are made, again
without removal of the laser tool from the well. This process can
be repeated until the desired flow, or other characteristics of the
borehole are achieved.
[0281] Thus, by way of example and generally, in an illustrative
hydraulic fracturing operation water, proppants, e.g., sand, acids
(with or without proppants) and additives are pumped at very high
pressures down the borehole. These liquids flow through perforated
sections of the borehole, and into the surrounding formation,
fracturing the rock and injecting the proppants into the cracks, to
keep the crack from collapsing and thus, the proppants, as their
name implies, hold the cracks open. During this process operators
monitor and gauge pressures, fluids and proppants, studying how
they react with and within the borehole and surrounding formations.
Based upon this data typically the density of sand to water is
increased as the frac progresses. This process may be repeated
multiple times, in cycles or stages, to reach maximum areas of the
wellbore. When this is done, the wellbore is temporarily plugged
between each cycle to maintain the highest water pressure possible
and get maximum fracturing results in the rock. These so called
frac-plugs or sliding sleeves are drilled or removed from the
wellbore and the well is tested for results. When the desired
results have been obtained the water pressure is reduced and fluids
are returned up the wellbore for disposal or treatment and re-use,
leaving the sand in place to prop open the cracks and allow the
hydrocarbons to flow. Further, such hydraulic fracturing can be
used to increase, or provide the required, flow of hot fluids for
use in geothermal wells, and by way of example, specifically for
the creation of enhanced (or engineered) geothermal systems
("EGS").
[0282] The present invention provides the ability to greatly
improve upon explosive based fracing processes, described above.
Thus, with the present invention, preferably before the pumping of
the fracing components begins, a very precise and predetermined
perforating pattern can be placed in the borehole. For example, the
shape, size, location and direction of each individual perforation
can be predetermined and optimized for a particular formation and
borehole. The direction of the individual perforation can be
predetermined to coincide with, complement, or maximize existing
fractures in the formation. Thus, although is it is preferred that
the perforations are made prior to the introduction of the fracing
components, these steps maybe done at the same time, partially
overlapping, or in any other sequence that the present inventions
make possible. Moreover, this optimization can take place in
real-time, without having to remove the laser tool of the present
invention form the borehole. Additionally, at any cycle in the
fracturing process the laser tool can be used to further maximize
the location and shape of any additional perforations that may be
desirable. The laser tool may also be utilized to remove the
frac-plugs.
[0283] A single high power laser may be utilized in or with these
systems, tools and operations, or there may be two or three high
power lasers, or more. High power solid-state lasers, specifically
semiconductor lasers and fiber lasers are preferred, because of
their short start up time and essentially instant-on capabilities.
The high power lasers for example may be fiber lasers, disk lasers
or semiconductor lasers having 5 kW, 10 kW, 20 kW, 50 kW, 80 kW or
more power and, which emit laser beams with wavelengths in the
range from about 455 nm (nanometers) to about 2100 nm, preferably
in the range about 400 nm to about 1600 nm, about 400 nm to about
800 nm, 800 nm to about 1600 nm, about 1060 nm to 1080 nm, 1530 nm
to 1600 nm, 1800 nm to 2100 nm, and more preferably about 1064 nm,
about 1070-1080 nm, about 1360 nm, about 1455 nm, 1490 nm, or about
1550 nm, or about 1900 nm (wavelengths in the range of 1900 nm may
be provided by Thulium lasers). An example of this general type of
fiber laser is the IPG YLS-20000. The detailed properties of which
are disclosed in US patent application Publication Number
2010/0044106. Thus, by way of example, there is contemplated the
use of four, five, or six, 20 kW lasers to provide a laser beam
having a power greater than about 60 kW, greater than about 70 kW,
greater than about 80 kW, greater than about 90 kW and greater than
about 100 kW. One laser may also be envisioned to provide these
higher laser powers.
[0284] The conveyance structure may be an optical fiber in a metal
tube with carbon fiber weave outer wrap, coiled tubing, a tube
within the coiled tubing, jointed drill pipe, jointed drill pipe
having a pipe within a pipe, or may be any other type of line
structure, that has a high power optical fiber associated with it.
For example, the conveyance structure may be a high power optical
fiber, having a core diameter of more than 250 microns, and
preferably more than 500 microns, surround by a reduced friction
protective layer, e.g., a gel or Teflon tube, which is then encased
within a metal tube, e.g., a stainless steel tube, which is
supported with carbon fibers, e.g., wrapped with a braded carbon
fiber or similar composite weave, and impregnated or coated with a
strong, abrasion resistant material. As used herein the term line
structure should be given its broadest meaning, unless specifically
stated otherwise, and would include without limitation: wireline;
coiled tubing; slick line; logging cable; cable structures used for
completion, workover, drilling, seismic, sensing, and logging;
cable structures used for subsea completion and other subsea
activities; umbilicals; cables structures used for scale removal,
wax removal, pipe cleaning, casing cleaning, cleaning of other
tubulars; cables used for ROV control power and data transmission;
lines structures made from steel, wire and composite materials,
such as carbon fiber, wire and mesh; line structures used for
monitoring and evaluating pipeline and boreholes; and would include
without limitation such structures as Power & Data Composite
Coiled Tubing (PDT-COIL) and structures such as Smart Pipe.RTM. and
FLATpak.RTM.. Conveyance structures would include without
limitation all of the high power laser transmission structures and
configurations disclosed and taught in the following US Patent
Applications Publication Nos.: 2010/0044106; 2010/0215326;
2010/0044103; 2012/0020631; 2012/0068086; and 2012/0266803, the
entire disclosures of each of which are incorporated herein by
reference.
[0285] The various embodiments of high power laser hydraulic
fracturing assemblies, perforating tools, systems and methods set
forth in this specification may be used with each other, and the
components of one embodiment may be used with, interchanged with,
or as a part of the components of other embodiments. The various
embodiments of high power laser hydraulic fracturing assemblies,
perforating tools, systems and methods set forth in this
specification may be used various high power laser systems and
conveyance structures and systems, in addition to those embodiments
of the figures and embodiments in this specification. For example,
they may use, or be used in, or with, the systems, lasers, optics,
tools and methods disclosed and taught in the following US patent
applications and patent application publications: Publication No.
2010/0044106; Publication No. 2010/0215326; Publication No.
2012/0275159; Publication No. 2010/0044103; Publication No.
2012/0267168; Publication No. 2012/0020631; Publication No.
2013/0011102; Publication No. 2012/0217018; Publication No.
2012/0217015; Publication No. 2012/0255933; Publication No.
2012/0074110; Publication No. 2012/0068086; Publication No.
2012/0273470; Publication No. 2012/0067643; Publication No.
2012/0266803; Publication No. 2013/0011102; Ser. No. 13/868,149;
Ser. No. 13/782,869; Ser. No. 61/798,597; Ser. No. 61/734,809; and
Ser. No. 61/786,763, the entire disclosure of each of which are
incorporated herein by reference.
[0286] The inventions may be embodied in other forms than those
specifically disclosed herein without departing from its spirit or
essential characteristics. The described embodiments are to be
considered in all respects only as illustrative and not
restrictive.
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