U.S. patent application number 14/015618 was filed with the patent office on 2014-03-06 for method and apparatus for treating a well.
This patent application is currently assigned to Texian Resources. The applicant listed for this patent is Texian Resources. Invention is credited to Douglas N. Love.
Application Number | 20140060837 14/015618 |
Document ID | / |
Family ID | 50185823 |
Filed Date | 2014-03-06 |
United States Patent
Application |
20140060837 |
Kind Code |
A1 |
Love; Douglas N. |
March 6, 2014 |
METHOD AND APPARATUS FOR TREATING A WELL
Abstract
A tool for forming an obstruction in the production casing of an
oil or gas well includes a sleeve adapted to be secured to the
casing and having an annular abutting surface that captures a body
or a cage having a solid body within the casing thereby forming an
obstruction. The tool may be secured within the well either by an
expandable sleeve or a collet having resilient fingers. The tool
may be used as a plug to prevent flow through the production casing
of the well in a well treatment process such as fracing. A process
for treating a well using the tool is also presented.
Inventors: |
Love; Douglas N.; (Granbury,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Texian Resources |
Granbury |
TX |
US |
|
|
Assignee: |
Texian Resources
Granbury
TX
|
Family ID: |
50185823 |
Appl. No.: |
14/015618 |
Filed: |
August 30, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13605298 |
Sep 6, 2012 |
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14015618 |
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Current U.S.
Class: |
166/297 ;
166/325 |
Current CPC
Class: |
E21B 33/12 20130101;
E21B 43/26 20130101; E21B 34/06 20130101; E21B 23/04 20130101; E21B
23/02 20130101 |
Class at
Publication: |
166/297 ;
166/325 |
International
Class: |
E21B 43/26 20060101
E21B043/26; E21B 34/06 20060101 E21B034/06 |
Claims
1. A tool for forming an obstruction in production casing of an oil
or gas well comprising: a sleeve adapted to be secured within the
production casing; a cage member having an annular surface adapted
to abut against a first end portion of the sleeve; and the cage
member having a solid body that is axially movable to a first
position blocking fluid flow through the tool in a first direction
and movable to a second position permitting fluid flow through the
tool in a direction opposite to the first direction.
2. The tool according to claim 1 wherein the cage member includes a
hollow cylindrical portion having a diameter slightly less than
that of the production casing and a hollow frustoconical portion
extending downstream of the hollow cylindrical portion and
terminating in an outlet.
3. The tool according to claim 1 wherein the cage member further
includes a perforated disk closing one end of the hollow
cylindrical portion of the cage member.
4. The tool according to claim 1 wherein the perforated disk
includes an annular wall spacing the solid body from a planar flat
portion of the disk.
5. A tool for forming an obstruction in the production casing of an
oil or gas well comprising: an expandable sleeve adopted to be
secured within the casing. a solid body having a frustonical shape
and having a surface portion adapted to abut against an annular
surface on the sleeve thereby forming an obstruction in the
well.
6. A tool for forming an obstruction of an oil or gas well having
production casing comprising: a sleeve having a passageway
therethrough; a plurality of collet fingers on the sleeve adapted
to engage a gap between adjacent production casing members; and a
ball or dart adapted to seat on a surface of the sleeve to close
the passageway.
7. A tool as claimed in claim 6 further including a cup-shaped
member having an interior surface conforming to the exterior
surface of the ball or dart and engaging an uphole surface of the
ball or dart.
8. A tool as claimed in claim 6 wherein the sleeve includes a valve
seat.
9. A method of treating a well having a production casing
comprising: providing a production casing including a plurality of
production casing members; securing a tool having a valve seat and
a through passageway at a predetermined position within the
production casing; perforating the production casing uphole of the
tool; closing the through passageway in the tool; and pumping a
treating fluid in the production casing and out through the
perforations.
10. The method of claim 9 including: terminating the pumping of the
treating fluid; positioning a second tool in the production casing
upstream of the perforations in the production casing; perforating
the production casing at a second location uphole of the second
tool and resuming pumping of the treating fluid in the production
casing and through perforations located in the second location.
11. The method of claim 9 wherein the tool includes a collet having
a plurality of resilient fingers with tabs, the tabs adapted to be
captured by a gap formed between adjacent production casing
members.
12. The method of claim 9 wherein the tool includes a collet having
a plurality of resilient fingers with tabs, the tabs adapted to be
captured by a groove within a connection sub that connects two
adjacent production casing members together.
Description
[0001] This is a Continuation-in-Part of application Ser. No.
13/605,298 filed on Sep. 6, 2012.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The invention disclosed and claimed in this application
relates to the treatment of oil and/or gas wells. One example of
such treatment is commonly referred to as fracturing the
formulation around an oil or gas well. Fluid with certain chemical
additives and a proppant are injected into the formation
surrounding either a vertical or horizontal well to form cracks or
passageways in the formation to stimulate the production of the
well.
[0004] 2. Description of Related Art
[0005] Currently there are several techniques utilized to stimulate
producing of a well by fracing. Typically a packer or plug is
utilized to isolate a particular portion of the well and the
fracing fluid is injected into the isolated portion under high
pressure. Once a given portion of the well is treated in this
manner, a second zone uphole of the first zone is isolated by a
second packer or plug that cuts off flow to the downhole portion of
the well that has been treated.
[0006] U.S. Pat. No. 7,322,417 discloses a plurality of vertically
spaced production layers 1 and a plurality of valves 14. A ball is
captured on a valve seat 94 which will cause an increase in
pressure to open valve 14. This allows fracturing fluids to enter
the annular region that surrounds the valve. The balls may be
formed of a dissolvable or frangible material, which allows the
ball to be dissolved or eroded to open up communication upstream
through the casing.
[0007] U.S. Pat. No. 7,134,505 discloses a similar system in which
a plurality of spaced apart packers 20 a-n and a plurality of valve
bodies 26 c-n that capture balls of varying diameters to
selectively open ports 16 c-e to allow fracturing fluids to flow
into the isolated zones.
[0008] Stage frac methods include the use of pump down bridge
plugs, perforating guns, and sliding sleeves. The current pump down
method requires a drill out phase after frac with coiled tubing or
jointed pipe. This is an expensive and time consuming process which
involves additional risk of the coil tubing getting stuck in the
wellbore. This time and operational risk is a significant impact
item on the overall economics of oil and gas projects.
[0009] Sliding sleeves require that their exact position needs to
be known as the casing is run into the well. The number of frac
initiation points is limited and the cost is significant for each
sleeve. Sleeves may malfunction either during opening or closing.
Higher risk comes from incomplete frac distribution and limited
reservoir drainage.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention overcomes the difficulties with the
prior art as described above by using proven concepts and a
simplified approach. An expansible valve seat or stop member that
can be run on wireline (pump-down, tractor, tubing or coiled
tubing) is positioned at predetermined locations along the
production casing and is expanded for example by a shaped charge or
with a mandrel extrusion process. A disintegrating or dissolvable
ball can be dropped in the valve seat to isolate a portion of the
well to allow for fracturing of the isolated portions of the well.
The seat may be made of the same material as the ball so that the
drill out step is completely eliminated. Alternately, the valve
seat may be mechanically captured by the production casing.
[0011] The ball and valve seat become the frac plug that would
normally be pumped down in a conventional horizontal pump-down
process.
[0012] The production casing can be perforated as in the pump down
method and fracing can be initiated once the ball seals on the
valve seat. A dart may be used in lieu of a ball. Balls, darts,
seats or sleeves may be soluble, dissolvable or frangible.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0013] FIG. 1 is a flow diagram of the process according to an
embodiment of the invention.
[0014] FIG. 2 is a cross sectional view of expansible sleeve seat
according to an embodiment of the invention.
[0015] FIG. 3 is a cross sectional view of the sleeve seat deployed
within the production casing with the ball.
[0016] FIG. 4 is a cross sectional view of a second expansible
sleeve seat and a dart.
[0017] FIG. 5 is a cross sectional view of a third expansible
sleeve seat and a ball.
[0018] FIG. 6 is a cross sectional view of a fourth embodiment with
an expansible sleeve and separate seat with a dart.
[0019] FIG. 7 is a cross sectional view of a fifth embodiment of
the invention.
[0020] FIG. 8 is an end view of the embodiment of FIG. 7.
[0021] FIG. 9 is a cross sectional view of a sixth embodiment of
the invention.
[0022] FIG. 10 is a cross sectional view of a further embodiment of
the invention.
[0023] FIG. 11 is a cross sectional view of yet a further
embodiment of the invention.
[0024] FIG. 12 is a cross sectional view of an embodiment of a
connector sub.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As described below, the invention of this application is
directed to a novel process of fracturing a plurality of zones in
the formation surrounding a horizontal or vertical well without the
use of multiple bridge plugs or frac plugs that require drill out
after the fracturing process is complete prior to the production
stage.
[0026] This is accomplished in the following manner. After the well
has been drilled (81) and the production casing has been fully
positioned (82), an expansible sleeve such as shown in FIG. 2 is
placed at the desired location within the casing (83). As shown in
FIG. 2, the expansible sleeve 10 consists of a relatively thin
walled cylindrical tube 11 formed of a high tensile strength
material similar to that of the production casing 21. A ring of
expansible material 12 may surround a portion of tube 11. A cap 15
is positioned over the downhole end 16 of the tube so that the
expansible sleeve 10 may be pumped into the well. The outside
diameter of the ring 12 is slightly less that the inside diameter
of the casing. Detonation cord 14 is wound about a frangible
mandrel 13 positioned within the tube and includes an electrical
cord 17 for detonation. Another embodiment of this invention may
employ the use of an extrusion process using a mandrel and sleeve
to create the seat as shown in FIG. 3. The resultant sleeve or seat
installed in the production casing will be the same whether the
installation process is expansive or extruded.
[0027] Expansible sleeve 10 may be precisely positioned within the
production casing by any suitable known technique such as a line
counter or collar locator. Once positioned within the desired
location of the production casing, the cord is detonated (84)
causing the sleeve to expand outwardly against the inner surface of
the casing (21). In so doing, the sleeve forms a seat 12 as shown
in FIG. 3 which is capable of catching and retaining a ball or dart
as shown in FIG. 3 and FIG. 4 that is pumped down (86). The outer
surface of tube 11 may be impregnated with a thin strip of no slip
high strength metallic material.
[0028] Once the tube 11 and seat have been set in place, the
production casing and cement (if present) in the first frac zone
can be perforated (85) in the conventional way by a perforating gun
on the same tool-string as the expansible sleeve. At this point the
tool-string can be removed, and the fracing process can be
initiated by pumping down (86) a ball or dart to rest against seat
12. This will prevent the fracing fluid from flowing downhole and
will cause the fracing fluid under pressure (87) to enter the
formation surrounding the perforations in the production casing and
thus commence the fracing process.
[0029] Once the process is completed for the first zone, a second
expansible sleeve can be placed (88) to isolate a second zone and
the process can be repeated (88-92) for as many zones as desired as
indicated in FIG. 1. The ball, dart, seat or sleeve may be made of
a soluble, dissolvable, or frangible material such that it would
not be necessary to drillout the sealing mechanism after
fracturing. The ball, dart, seat or sleeve would shrink in size or
completely dissolve so that the constituents went into solution or
were flowed back with the frac load water.
[0030] Another embodiment of the expansible sleeve is illustrated
in FIG. 5. In this embodiment, a tubular member is shown in an
unexpanded condition at 45. Chevron or swellable seals 43 are
positioned about an uphole portion 44 of the sleeve 45. Sleeve
portion 45 is expanded by a mandrel or shaped charge into the
position indicated at 46 against the inner surface of the casing
21. In this embodiment the uphole portion 44 of the sleeve may have
a beveled surface (47) against which ball 22 rests when a ball or
dart is pumped down into the casing.
[0031] An additional embodiment of the expansible sleeve is
illustrated in FIG. 6. In this embodiment, a sleeve 11 is expanded
in the production casing 21 and used as a stop or no-go for a
secondary conical seat 51 that is either simultaneously or
subsequently placed on the no-go. The perforations are then added.
A ball or dart 32 is then landed on the seat forming the sealing
mechanism for the wellbore and the stage is frac'd. Secondary seat
51 may have an elastomeric annular seat 52 that engages a tapered
portion 53 of the sleeve 11 to form a seal. This process can be
repeated as many times as necessary to adequately stimulate the
formation surrounding the wellbore. The ball, dart or seat in this
embodiment may also be made of a soluble, dissolvable, or frangible
material.
[0032] A further embodiment of the invention can be described by
reference to FIGS. 7 and 8. As with other embodiments, an
expandable sleeve 10 is positioned and expanded within production
casing 21 so that cylindrical tube 11 is secured to the casing. A
cage member 65 having a ball 66 is then pumped down to a position
where it rests on shoulder 53 of tube 11 as shown in FIG. 7. Cage
member 65 has a hollow cylindrical portion 62 of slightly less
diameter than the internal diameter of casing 21. Cage member also
has a hollow frustoconical portion 61 which terminates in an outlet
68.
[0033] A perforated disk 64 having perforations 63 closes one end
of the cage as shown in FIG. 7. Disk 63 includes an annular wall
portion 67 which spaces ball 65 from disk 64. The diameter of ball
63 is smaller than the inside diameter of cylindrical portion 62 of
cage 65 so that fluid can flow from right to left, looking at FIG.
7, around ball 65 and through apertures 63. However, cage 65 will
prevent fluid flow from left to right as in fracing operations by
virtue of ball 66 resting on frustoconical portion 61 of the
cage.
[0034] As in previous embodiments, the sleeve 11, cage member 62
and ball 66 may be made of a soluble, dissolvable or frangible
material so that it would not be necessary to drill out the sealing
mechanism after fracing.
[0035] Another embodiment of the invention is illustrated in FIG.
9. This embodiment also utilizes a cylindrical tube 11 that has
been expanded so to be secured within casing 21. A solid
frustoconical plug 71 after being pumped down into the well, rests
against shoulder 53 of tube 11 at 72 as shown in FIG. 9 to prevent
flow downhole of the plug 71. Plug 71 may also be made of a
soluble, dissolvable or frangible material.
[0036] The expandable sleeve may be formed of steel for example
J-55 or similar steel. The wall thickness may vary from
approximately 0.095 inches to about 0.25 inches. The diameter of
the sleeve is selected to be slightly smaller than that of the
production casing so for example if the casing is 5 1/2 inch
casing, the sleeve may have an outside diameter of 4.5 inches.
[0037] A further embodiment of a tool suitable for use according to
the invention is shown in FIG. 10. The tool 100 includes a hollow
cone shaped sleeve 103 having an end portion having an outlet 119
formed therein. Sleeve 103 includes an internal converging
passageway 110 leading to outlet 119. The uphole end of the tool
includes a plurality of radially spaced resilient collet style
fingers 108 which each include a tab member 105 of a given width.
The tabs 105 are sized to mate with an annular gap 107 formed
between two sections of production casing 101. The two sections 101
are secured together by a coupling 104. Tool 100 may be run into
the well with a disposable setting sleeve in conjunction with
select fire perforating guns. As tabs 105 come into alignment with
gap 107 having the same width as the tabs 105, fingers 108 will
expand outwardly in a known manner to lock the tool within the
production casing. A ball or dart 106 can then be dropped into the
production casing and will engage a converging wall section of
sleeve 103 to thereby act as a frac plug. Ball or dart 106 may be
made from a bio degradable material that dissolves. Sleeve 103 may
be made from a degradable fiberglass resin or any other degradable
material so that it does not need to be drilled out. This process
can be repeated to form plural fracing zones. Each tool or plug 100
will have tabs 105 having a unique width so that the collet fingers
will only be captured by a gap between the production casing
members having the corresponding width.
[0038] A cup shaped member 112 having seals 113 can be positioned
on the uphole portion of ball or dart 106 to provide a seal. The
internal surface of cup 112 is formed to conform to the spherical
surface of ball or dart 106.
[0039] FIG. 11 illustrates yet a further embodiment of a tool
according to an aspect of the invention. In this embodiment the
tool includes an outer collet sleeve 127 that is deployed from
inside a setting tool and is run in a wire string in the same
manner that a frac plug would be run. Outer collet sleeve 127
includes a plurality of resilient collect fingers 131 having tabs
123 of a given width that mate with a gap 122 formed between
adjacent production casing members 111 that are coupled together by
a threaded coupler 121 for example. A valve seat 125 having a
downhole end 129 is captured within collet sleeve 127 by virtue of
complementary converging surfaces on the inside of the collet
sleeve 127 and on the outer surface of valve seat 125. Valve seat
125 includes a converging passageway 130 which may be initially
filled by a bio-degradable material. Valve seat 125 may be
separately carried down to engage collet sleeve 127. Valve seat 125
carries an annular sealing ring 124 which is compressed outwardly
against production casing 111 as valve sleeve 125 is forced, for
example, by fluid pressure into collet sleeve 127.
[0040] After the collet sleeve and valve seat have been positioned
within the production casing and the casing has been perforated, a
ball or dart can be run in or dropped to engage valve seat 125 to
form a plug. At this point, the perforated zone of formation uphole
of the plug can now be treated. As in other embodiments the collet
sleeve, valve seat and dart or ball can be made of bio-degradable
or dissolvable material.
[0041] Collet sleeve 127 and valve seat 125 may be run into the
production casing separately or loosely attached to each other by
an attachment mechanism, for example a shear pin, that can be
disengaged by a suitable force applied to the valve seat such as
fluid pressure.
[0042] As in the embodiment of FIG. 10, each plug will have unique
width tabs so as to be selectively placed within the production
casing. The gaps between adjacent production casing members will
have different widths to selectively capture the collet sleeves.
Typically the first tool placed at the end of the production casing
will have the widest tabs so as to pass over gaps of a smaller
width as the tool is run into the production casing.
[0043] The embodiments of FIGS. 10 and 11 could be used in
conjunction with a casing profile nipple (CPN). In lieu of having
the tabs of the collet fingers being captured in a gap between
production casing members, the tabs could be captured by an annular
groove provided on the interior of a casing profile nipple which
can be connected between adjacent production casing members as is
known in the art. A suitable CPN is manufactured by Tesco
Corporation. Additionally, a simple connector sub with an interior
annular groove could be utilized as the securing mechanism for the
embodiments of FIGS. 10 and 11. As shown in FIG. 12, the connector
sub 200 has threaded end portions 201, 202 and a cylindrical
tubular body portion 203. An annular groove 204 is formed in the
interior surface of body portion 203. The groove is sized to
accommodate tabs 105 or 123 on the end of the collet fingers 108 or
131.
[0044] Although the present invention has been described with
respect to specific details, it is not intended that such details
should be regarded as limitations on the scope of the invention,
except to the extent that they are included in the accompanying
claims.
* * * * *