U.S. patent application number 13/292279 was filed with the patent office on 2012-05-17 for system, apparatus and method for abrasive jet fluid cutting.
Invention is credited to Mark Franklin Alley, Wesley Mark McAfee.
Application Number | 20120118562 13/292279 |
Document ID | / |
Family ID | 46046755 |
Filed Date | 2012-05-17 |
United States Patent
Application |
20120118562 |
Kind Code |
A1 |
McAfee; Wesley Mark ; et
al. |
May 17, 2012 |
SYSTEM, APPARATUS AND METHOD FOR ABRASIVE JET FLUID CUTTING
Abstract
A system, apparatus and method for abrasive jet fluid cutting is
provided wherein an abrasive jet fluid cutting assembly comprises a
hose for receiving a coherent abrasive jet-fluid containing a solid
abrasive; a helix/spring attached inside the high-pressure hose;
and a jet-nozzle connected to the hose. Wherein the coherent
abrasive laden jet-fluid is pumped under high pressure through the
high-pressure hose and across the helix. As the jet-fluid traverses
the helix, the jet-fluid rotates at a high rate creating a vortex.
The disclosed subject matter further includes a system and method
for using the abrasive jet fluid cutting nozzle assembly.
Inventors: |
McAfee; Wesley Mark;
(Montgomery, TX) ; Alley; Mark Franklin;
(Nashville, TN) |
Family ID: |
46046755 |
Appl. No.: |
13/292279 |
Filed: |
November 9, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11938830 |
Nov 13, 2007 |
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13292279 |
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60865638 |
Nov 13, 2006 |
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Current U.S.
Class: |
166/222 |
Current CPC
Class: |
E21B 43/114 20130101;
E21B 7/18 20130101; E21B 43/112 20130101; E21B 29/06 20130101; E21B
10/60 20130101 |
Class at
Publication: |
166/222 |
International
Class: |
E21B 43/114 20060101
E21B043/114 |
Claims
1. Apparatus for cutting through casing, cement and/or formation
rock, the apparatus comprising: a high-pressure hose, said
high-pressure hose at least internally lined substantially with an
abrasive resistance material, said abrasive resistant material
either a non-rigid abrasive resistant material or a rigid abrasive
resistant material; a helix disposed within said high-pressure hose
between a jet-nozzle and any significant bend in said high-pressure
hose, said helix at least externally lined substantially with a
first rigid abrasive resistant material; said jet-nozzle directly
associated with said high-pressure hose, said jet-nozzle at least
internally lined substantially with a second rigid abrasive
resistant material; a coherent abrasive jet-fluid, said coherent
abrasive jet-fluid containing a solid abrasive and traveling under
pressure through said high-pressure hose, over said helix, and
through said jet-nozzle; wherein said abrasive-jet-fluid is used to
cut a target.
2. The apparatus according to claim 1, wherein the length of the
fully constricted portion of said jet-nozzle and said high-pressure
hose to a distal end of said jet-nozzle is less than 50 mm.
3. The apparatus according to claim 1, wherein a distal end of said
jet-nozzle is tapered.
4. The apparatus according to claim 1, wherein said jet-nozzle is
comprised of: a nozzle holder assembly, wherein said high-pressure
hose is associated with said nozzle holder assembly; a nozzle; a
nozzle end retainer, wherein said nozzle is positioned between said
nozzle end retainer and said nozzle holder assembly and said nozzle
end retainer compresses said high-pressure hose between said nozzle
holder assembly and said nozzle end retainer.
5. The apparatus according to claim 4, wherein a distal end of said
nozzle end retainer is tapered.
6. The apparatus according to claim 5, wherein said tapering of
said distal end of said nozzle end retainer is approximately 30
degrees.
7. The apparatus according to claim 4, wherein said nozzle extends
through said nozzle end retainer and through said tapering such
that a distal end of said nozzle substantially aligns with said
distal end of said nozzle end retainer.
8. The apparatus according to claim 4, wherein said jet-nozzle
length is tuned so the maximum velocity of said coherent abrasive
jet-fluid occurs at a distal end of said jet-nozzle, said tuning
accomplished by measuring the mass flow and pressures of said
jet-nozzle and adjusting said jet-nozzle length until there is a
decrease of back pressure at the proximate end of said
jet-nozzle.
9. The apparatus according to claim 1, wherein said helix is
disposed within a sleeve, said sleeve disposed within said
high-pressure hose.
10. The apparatus according to claim 9, wherein said helix and said
sleeve are positioned substantially against a proximate end of said
nozzle holder assembly.
11. The apparatus according to claim 1, wherein said helix has a
larger outer diameter than the inner diameter of said nozzle holder
assembly.
12. The apparatus according to claim 1, wherein said helix has a
smaller inner diameter area than the inner diameter area of said
high-pressure hose.
13. The apparatus according to claim 12, wherein said helix's
smaller inner diameter area increases said coherent abrasive
jet-fluid's velocity as said coherent abrasive jet-fluid traverses
said helix.
14. The apparatus according to claim 1, wherein said coherent
abrasive-jet-fluid is pumped under high-pressure between a range of
690 bar and 2,750 bar.
15. The apparatus according to claim 1, the apparatus capable of
cutting through said target, wherein said target is a 19 mm thick
piece of steel positioned 1.5 meters from said jet-nozzle and said
cutting is performed in the air.
16. The apparatus according to claim 1, the apparatus capable of
cutting through said target, wherein said target is 600 mm thick
steel reinforced concrete and said cutting is performed in the
air.
17. The apparatus according to claim 1, the apparatus capable of
cutting said target, wherein said target is a 380 mm thick steel
and said cutting is performed in the air.
18. The apparatus according to claim 1, the apparatus capable of
being deployed within a well bore with an internal diameter of 101
mm.
19. The apparatus according to claim 1, the apparatus capable of
cutting steel casing(s), cement, and/or formation rock at least two
feet from said jet-nozzle while said jet-nozzle is submerged in a
liquid.
20. The apparatus according to claim 19, said jet-nozzle cutting
through and severing from the ID of a casing through five cemented
nested casings with the largest nested casing being one meter in
diameter.
21. The apparatus according to claim 1, wherein said target is 19
mm thick steel casing(s), cement, and/or formation rock and said
target is cut at a rate of at least 300 mm length per minute while
said jet-nozzle is submerged in a liquid.
22. The apparatus according to claim 1, said jet-nozzle submerged
within a liquid and cutting while submerged in said liquid.
23. The apparatus according to claim 1, wherein said target is
casing(s), cement, and/or formation rock and said cutting is
performed at greater than 6 km depth while submerged in a
liquid.
24. The apparatus according to claim 1, wherein said target is a
casing and/or subterranean formation.
25. The apparatus according to claim 1, wherein said coherent
abrasive jet-fluid is capable of cutting a hole in said target
larger than the diameter of said jet-nozzle without moving said
jet-nozzle.
26. The apparatus according to claim 1, wherein said apparatus does
not need an aqueous gel for operation.
Description
[0001] This application is a continuation-in-part of pending U.S.
Non-Provisional No. 11/938,830, filed Nov. 13, 2007 and entitled
"SYSTEM, APPARATUS AND METHOD FOR ABRASIVE JET FLUID CUTTING" which
claims the benefit of U.S. Provisional No. 60/865,638 filed on Nov.
13, 2006, entitled "SYSTEM AND APPARATUS FOR A JET-FLUID CUTTING
NOZZLE" and is hereby incorporated by reference.
FIELD
[0002] The present disclosure relates to drilling and cutting
systems and their methods of operation and, more particularly, to a
system and apparatus for a jet-fluid cutting nozzle.
BACKGROUND OF THE DISCLOSURE
[0003] Many wells today have a deviated bore horizontally drilled
extending away from a generally vertical axis main well bore. The
use of horizontal drilling technology has increased production
fourfold over that previously achieved from vertical wells. The
drilling of such sidetracking is accomplished via multiple steps.
After casing and cementing a well bore, historically a multi-stage
milling process is employed to vertically mill cut a window through
one side of the casing. Once a vertical window is milled through
the casing at the desired sidetrack or kickoff location, a
directional or horizontal well drilling process may begin.
[0004] Although simple in concept, the execution of casing window
milling is complicated and difficult to achieve in a timely
fashion. Several complicating factors are that the well bore casing
is made of steel or similarly hard material and the casing is
difficult to access down a deep well borehole.
[0005] A whip-stock wedge must be placed in the casing at the
desired well bore depth location and locked in place in the
direction for sidetracking, as disclosed in U.S. Pat. No.
5,109,924. The whip-stock wedge can then deflect the vertical
rotating milling cutter's path to one side of the casing, for
milling a sidetrack or kickoff window opening through that side of
the casing. The sidetrack window entry point machined through the
steel casing is narrow at the top, and can cause the sidetracking
rotating drill pipe to be damaged and break, because of the rubbing
of the rotating drill pipe against the narrow top window opening
and burrs left on the machined casing. Historically it is not
uncommon to take 10 hours to complete the milling of the window
profile(s) through the casing using conventional machining
processes.
[0006] Abrasive casing cutting with jet nozzles has been attempted
to replace conventional milling, but the present abrasive cutting
processes cannot achieve proper casing window cutting required for
sidetracking or horizontal drilling.
[0007] A prior art method and apparatus for cutting round
perforations and an elongated slot in well flow conductors was
offered in U.S. Pat. No. 4,134,453, which is hereby incorporated by
reference as if fully set forth herein. The disclosed apparatus has
jet nozzles in a jet nozzle head for discharging a fluid to cut the
perforations and slots. A deficiency in this prior art method is
that the length of the cuts that the disclosed jet nozzle makes
into the rock formation is limited because the jet nozzle is
stationary with respect to the jet nozzle head.
[0008] Another prior art method and apparatus for cutting panel
shaped openings is disclosed in U.S. Pat. No. 4,479,541, which is
hereby incorporated by reference as if fully set forth herein. The
disclosed apparatus is a perforator having two expandable arms.
Each arm having an end with a perforating jet disposed at its
distal end with a cutting jet emitting a jet stream. The cutting
function is disclosed as being accomplished by longitudinally
oscillating, or reciprocating, the perforator. By a sequence of
excursions up and down within a particular well segment, a deep
slot is claimed to be formed.
[0009] The offered method is deficient in that only an upward
motion along a well bore is possible due to the design of the
expandable arms. Furthermore, the prior art reference does not
provide guidance as how to overcome the problem of the two
expandable arms being set against the well bore wall from
preventing motion in a downward direction. A result of the prior
art design deficiency is that sharp angles are formed between the
well wall, thereby causing the jet streams emitted at the jets at
the distal ends of the expandable arms to only cut small scratches
into the well bore walls.
[0010] A further prior art method and apparatus for cutting slots
in a well bore casing is disclosed in U.S. Pat. No. 5,445,220,
which is hereby incorporated by reference as if fully set forth
herein. In the disclosed apparatus a perforator is comprised of a
telescopic and a double jet nozzle means for cutting slots. The
perforator centered about the longitudinal axis of the well bore
during the slot cutting operation.
[0011] The perforator employs a stabilizer means, which restricts
the perforator, thus not allowing any rotational movement of the
perforator, except to a vertical up and down motion. Additionally,
the lifting means of the perforator was not shown or described.
[0012] An additional prior art method and apparatus for cutting
casing and piles is disclosed in U.S. Pat. No. 5,381,631, which is
hereby incorporated by reference as if fully set forth herein. The
disclosed apparatus provides for a rotational movement in a
substantially horizontal plane to produce a circumferential cut
into the well bore casing. The apparatus drive mechanism is
disposed down hole at the location near the cut target area. The
prior art reference is deficient in that the apparatus requires
multi-hoses to be connected from the surface to the apparatus for
power and control.
[0013] The prior art methods are also deficient in that often the
cutting line established by the cutting nozzle creates a pie or
fanned shape cut as it penetrates the casing. This causes
difficulty in removing the pieces cut out by conventional means,
due to the fact the rear face of the piece is larger than the
opening cutout by the cutting tool. This necessitates either
additional cutting of the target or the angling of the line of
cutting to compensate for this problem and thus yield a rear face
of smaller dimensions than the front face of the casing.
[0014] Additionally, existing nozzles attempting to use a coherent
abrasive laden fluid while under water (or within another liquid)
have to displace the water with a gas for effective cutting of a
target greater than 150 mm distance from the nozzle.
[0015] There is a need for an abrasive-jet-fluid cutting nozzle and
system that is capable of creating any desired opening in the
casing(s).
[0016] There is a need, therefore, for a method and apparatus of
cutting precise shape and window profile(s), which can be
accomplished more quickly and less expensively.
[0017] An additional need is to perforate casings, cut pilings
below the ocean floor and to slot well bore casings using the
unique programmed movement of a jetting-shoe.
SUMMARY OF THE DISCLOSURE
[0018] This disclosure relates to the cutting of perforation(s),
slot(s), shape(s), and window(s) in submerged down-hole well bore
casing(s) whose inside diameter is about 100 mm or larger, and more
particularly, to the controlled and precise use of a jet-fluid and
nozzle configuration to cut perforation(s), slot(s), shape(s) and
window(s) through a well bore casing or multiple nested well bore
casings, thereby facilitating and providing access to the formation
structure beyond the casing(s) or completely severing a single or
multiple nested well bore casings where the casing(s) may be
cemented in place at any depth.
[0019] Programmed movement of a jetting-shoe and
abrasive-jet-nozzle allows lower kick off points and landing early
in the reservoir, due to the ability of short radius sidetracking
provided by cutting larger and longer casing window sections than
is possible with conventional machining processes.
[0020] Short-radius technology is employed for the re-entry of
existing vertical wells and to prevent having to kick off the well
into problem zones. Short-radius wells are those with a build-up
rate higher than 25.degree./30 m.
[0021] Another aspect of using programmed movement of a
jetting-shoe and abrasive-jet-nozzle is that it eliminates the
requirement to first deploy a whip-stock wedge placed in the casing
at the desired well bore depth location required for sidetracking
during conventional milling of the casing window.
[0022] The present disclosure has been made in view of the above
circumstances and has as an aspect a down hole jet-fluid cutting
apparatus capable of cutting well-bore casing(s) by the application
of coherent high-pressure abrasive fluid mixture.
[0023] A further aspect of the present disclosure is a novel nozzle
and nozzle configuration creating a vortex in the region directly
in front of the nozzle and that vortex travels downstream a
distance away from the nozzle and thereby generates additional
cutting and penetrating capabilities.
[0024] An additional aspect of the present disclosure is the
ability to use a flexible hose attached directly to the jet
nozzle.
[0025] Yet another aspect of the present disclosure is the ability
to use the device in well bores at least 100 mm in diameter.
[0026] Still another aspect of the disclosed subject matter is
extended effective cutting distances from the nozzle.
[0027] Another aspect of the disclosed subject matter is cutting at
great depth. An additional aspect of the disclosed subject matter
is the ability to conduct coherent abrasive jet-fluid cutting under
water or submerged in another liquid.
[0028] To achieve these and other advantages and in accordance with
the purpose of the present disclosure, as embodied and broadly
described, the present disclosure can be characterized according to
one aspect of the present disclosure as comprising a down-hole
jet-fluid cutting apparatus, the apparatus including a jet-fluid
nozzle, a high-pressure pump, wherein the high-pressure pump exerts
pressure on a motive fluid. The motive fluid from the high-pressure
pump, propels a fluid abrasive mixture from an abrasive mixing unit
that is capable of maintaining a coherent abrasive fluid mixture,
into a high-pressure conduit for delivering the coherent
high-pressure abrasive mixture to the down-hole jet-fluid
nozzle.
[0029] A jet-fluid nozzle jetting-shoe is employed, wherein the
jetting-shoe is adapted to receive the jet-fluid nozzle and direct
the coherent high-pressure jet-fluid abrasive mixture towards a
casing or target, wherein the jetting-shoe controlling unit further
includes at least one servomotor for manipulating the work string
and the jetting-shoe along a vertical and horizontal axis.
[0030] A central processing unit having a memory unit, wherein the
memory unit is capable of storing profile generation data for
cutting a predefined shape or window profile in the target. The
central processing unit further includes software, wherein the
software is capable of directing the central processing unit to
perform the steps of: controlling the jetting-shoe control unit to
manipulate the jetting-shoe along the vertical and horizontal axis
to cut a predefined shape or window profile in the target. The
jetting-shoe control unit controls the speeds and feeds of the work
string in the vertical and horizontal axial movement of the
tubing-work-string and jetting-shoe to cut a predefined shape or
window profile in the target. The software controls the percentage
of the abrasive fluid mixture to total fluid volume and also
controls pressure and flow rates of the high-pressure pump.
[0031] Inserting a jetting-shoe assembly via a tubing-work-string
into an annulus of the well bore casing to the milling site depth
and attaching rotating centralizers on an outer diameter surface of
the tubing-work-string to center the tubing-work-string in the
annulus. Milling of the site via an abrasive-jet fluid from the
jetting-shoe assembly is performed, wherein the computer implements
a predefined shape or window profile at the milling site by
controlling the vertical movement and horizontal movement through a
360 degree angle of rotation of the jetting-shoe assembly.
[0032] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the disclosure, as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the disclosure and together with the description, serve to explain
the principles of the disclosure.
[0034] FIG. 1 is a two dimensional cutaway view showing an
embodiment of the programmable abrasive-jet-fluid cutting system of
the present disclosure;
[0035] FIG. 2 is a two dimensional cutaway view depicting an
embodiment of the jack of the present disclosure;
[0036] FIG. 3 is a three-dimensional cutaway view of an embodiment
of a jetting-shoe of the present disclosure;
[0037] FIGS. 4A and 4B are three dimensional cutaway views of a
rotator of the present disclosure;
[0038] FIG. 5 is an exploded cutaway view of a nozzle assembly of
an aspect of the present disclosure;
[0039] FIG. 6 is a perspective view of an embodiment of an
assembled nozzle configuration of an aspect of the present
disclosure; and
[0040] FIG. 7 is an expanded view of FIG. 1 depicting an aspect of
the present disclosure in operation.
[0041] FIG. 8 is an exploded view of an alternative embodiment of
the helix and hose assembly.
[0042] FIG. 9 is an exploded cutaway view of an embodiment of the
nozzle assembly of an aspect of the present disclosure.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0043] Reference will now be made in detail to the present
embodiments of the disclosure, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts (elements).
[0044] To help understand the advantages of this disclosure the
accompanying drawings will be described with additional specificity
and detail.
[0045] The present disclosure generally relates to methods and
apparatus of abrasive-jet-fluid cutting through well bore casing or
similar structure. The method generally is comprised of the steps
of positioning a jetting-shoe and jet-nozzle adjacent to a
pre-selected location of casing in the annulus, pumping a motive
fluid containing abrasives through the jet-nozzle such that the
fluid is jetted there from cutting through the casing, while moving
the jetting-shoe and jet-nozzle in a predetermined programmed
vertical axis and 360 degree horizontal rotary axis.
[0046] In one embodiment of the present disclosure the vertical and
horizontal movement pattern(s) are capable of being performed
independently of each or programmed and operated simultaneously.
The abrasive-jet-fluid there from is directed and coordinated such
that the predetermined pattern is cut through the inner surface of
the casing to form a shape or window profile(s), allowing access to
the formation beyond the casing.
[0047] A jetting-shoe control unit simultaneously moves a
jetting-shoe in a vertical axis and 360-degree horizontal rotary
axis to allow cutting the casing, cement, and formation rock, in
any programmed shape or window profile(s). A coiled tubing for
delivering a coherent high-pressure abrasive-jet-fluid through a
single tube and a jet-nozzle for ejecting there from
abrasive-jet-fluid under high-pressure from a jetting-shoe is
contemplated and taught by the present disclosure. Coiled tubing
well intervention has been known in the oil production industry for
many years. Additional conductors such as high-pressure hoses and
tubing-work-strings can deliver the coherent high-pressure
abrasive-jet-fluid to the jetting-shoe.
[0048] The jetting-shoe control unit apparatus and means are
programmable to simultaneously or independently provide vertical
axis and 360-degree horizontal rotary axis movement under computer
control. A computer having a processor and memory and operating
pursuant to attendant software, stores shape or window profile(s)
templates for cutting and is also capable of accepting inputs via a
graphical user interface, thereby providing a system to program new
shape or window profile(s) based on user criteria. The memory of
the computer can be one or more of but not limited to RAM memory,
flash memory, ROM memory, EPROM memory, EEPROM memory, registers,
hard disk, a removable disk, an optical drive, floppy disk, DVD, CD
disk or any other form of storage medium known in the art. In the
alternative, the storage medium may be integral to the processor.
The processor and the storage medium may reside in an ASIC or
microchip.
[0049] The computer of the present disclosure controls the profile
generation servo drive systems as well as the abrasive mixture
percentage to total fluid volume and further controls the pressure
and flow rates of a high-pressure pump and pump drive. The computer
further controls the feed speed position of the fluid-tube fed
through the coiled tubing injector head and the simultaneous
jacking and the directional rotation of the tubing-work-string in
an annulus. Telemetry is broadcast and transmitted by a sensor or
probe located in the jetting-shoe after scanning of the cut shape
or window profile(s) after the casing has been cut.
[0050] In an alternate embodiment of the present disclosure the
abrasive-jet-fluid method and apparatus is capable of cutting into
the underlying substructure, such as rock or sediment.
[0051] In a further embodiment of the present disclosure the
abrasive-jet-fluid cutting apparatus can be directed to cut or
disperse lodged impediments blocking the well bore casing annulus.
Impediments such as measuring equipment, extraction tools, drill
heads or pieces of drill heads and various other equipment utilized
in the industry and readily recognizable by one skilled in the art,
periodically become lodged in the well bore and must be removed
before work at the site can continue.
[0052] In a still further embodiment multiple jet heads can be
employed to form simultaneous shapes or window profiles in the well
bore casing or underlying substructure, as the application
requires. This type of application, as appreciated by one skilled
in the art, can be employed to disperse impediments in the well
bore or to severe the well bore casing at a desired location so
that it can be extracted. Additionally, this embodiment can be
employed where a rock formation or other sub-structure is desired
to be shaped symmetrically or asymmetrically to assist in various
associated tasks inherent to the drilling or extraction
process.
[0053] In a still further embodiment of the present disclosure the
vertical axis of the cutting apparatus is capable of being
manipulated off the plane axis to assist in applications wherein
the well bore is not vertical, as is the case when directional
drilling is employed.
[0054] In one embodiment of the present disclosure, the
jetting-shoe is attached to a tubing-work-string and suspended at
the wellhead and is moved by the computer, central processing unit
or micro-chip (collectively called the computer) controlled servo
driven units. Software in communication with sub-programs gathering
telemetry from the site directs the computer, which in turn
communicates with and monitors the down hole cutting apparatus and
its attendant components, and provides guidance and direction
simultaneously or independently along the vertical axis and the
horizontal axis (360-degrees of movement) of the tubing-work-string
via servo driven units.
[0055] The shape or window profile(s) that are desired are
programmed by the operator on a programmable logic controller
(PLC), or personal computer (PC), or a computer system designed for
this specific use. The integrated software, via a graphical user
interface (GUI), accepts inputs from the operator and provides the
working parameters and environment by which the computer directs
and monitors the cutting apparatus.
[0056] The rotational computer controlled axis servo motor, such as
a Fanuc model D2100/150is servo, provides 360-degree horizontal
rotational movement of the tubing-work-string using a tubing
rotator such as R and M Energy Systems heavy duty model RODEC RDII,
or others, that have been modified to accept a mechanical
connection for the servo drive motor. The tubing-work-string
rotator supports and rotates the tubing-work-string up to 58 metric
tonnes. Geared slewing bearing rotators may also be used as will be
apparent to those skilled in the art.
[0057] The vertical axis longitudinal computer controlled servo
axis motor, such as Fanuc D2100/150is servo, provides up and down
vertical movement of the tubing-work-string using a jack assembly
attached to the top of the wellhead driven by said servo drive
motor. The jack could employ ball screw(s) for the ease of the
vertical axis longitudinal movements, although other methods may be
employed. The jack may have a counter balance to off set the weight
of the tubing-work-string to enhance the life of the servo lifting
screw(s) or other lifting devices such as Joyce/Dayton model WJT
325WJ3275 screw jack(s).
[0058] The servos simultaneously drive the tubing-work-string
rotator and jack, providing vertical axis and 360-degree horizontal
rotary axis movement of the tubing-work-string attached to the
down-hole jetting-shoe. The shape or window profile(s) cutting of
the casing is thus accomplished by motion of the down hole
jetting-shoe and the abrasive-jet-fluid jetting from the jet-nozzle
into and through the casing, cement, tools, equipment and/or
formations.
[0059] The abrasive-jet-fluid in one embodiment of the present
disclosure is delivered by a coiled tubing unit through a
fluid-tube to the jetting-shoe through the inner bore of the
tubing-work-string, or the abrasive-jet-fluid can be pumped
directly through the tubing-work-string, with the jet-nozzle being
attached to the exit of the jetting-shoe.
[0060] The abrasive-jet-fluid jet-nozzle's relative position to the
target is not critical due to the long reach coherent stream of the
abrasive-jet-fluid. The jet-nozzle angle nominally is disposed at
approximately 90 degrees to the inner well bore surface, impediment
or formation to be cut, but may be positioned at various angles in
the jetting-shoe for tapering the entry hole into the casing and
formation by the use of different angles where the jet-nozzle exits
the jetting-shoe.
[0061] The minimum 600 mm reach of the coherent stream
abrasive-jet-fluid jet-nozzle's abrasive-jet-fluid makes possible
the slotting and window cutting through multiple nested cemented
well bore casings. The long reach of the coherent stream
abrasive-jet-fluid exiting from the jet-nozzle as described herein,
allows cutting multiple slots vertically into the ID circumference
of the first casing facing the jet-nozzle, and then through
multiple nested casing into the rock formation.
[0062] While cutting the vertical slots through the casing, the
rotating abrasive jet stream from the jet-nozzle erodes the cement
between the first and other nested casing. The resulting cement
slurry generated from between the nested casing during the cutting
may be either pumped to the surface or left to settle into the well
bore hole.
[0063] Empirical tests cutting 25 mm radial spaced vertical 300 mm
length slots, with all slots starting at the same depth, removed
all the cement between the casing and formation. The method of
removing the cement between the nested casing and leaving the
resulting skeleton casing in place allow complete cementing from
one side of the formation to the opposite side giving a "rock to
rock" cement plug for shutting in wells permanently. The casing
skeleton left in place from the slotting and cement removal
provides additional strength to the cement plug.
[0064] The method for preparing the well for cement plugging is to
first deploy a tubing-work-string of sufficient length into the
well bore annulus using a work over rig with the jetting-shoe
assembly attached on the end of the work string. A casing log may
be consulted, at the zone where the well is to be plugged, along
with casing collar locations for information for programming the
jetting-shoe apparatus. A program is entered into the computer
where the jet-fluid nozzle jetting-shoe has been deployed, wherein
the jetting-shoe is adapted to receive the jet-fluid nozzle and
direct the coherent high-pressure jet-fluid abrasive mixture
towards a casing or target.
[0065] The high-pressure pump is turned on and coherent abrasive
fluid is pumped from the abrasive mixer into a high-pressure hose,
or a tubing-work-string, or coiled tubing, then through the
jetting-shoe assembly exiting the attached jet-nozzle to a
predefined point at the target. Observing about a 4 to 7 bar drop
on the high pump pressure gage, either on the pump or in the
control cab, that relates to the abrasive-jet fluid has blown a
hole through the target, then start the programmed vertical
movement of the jetting-shoe apparatus at 300 mm per minute,
cutting a slot 1.5 meters in length. Slot cut length without
re-positioning the work-string is dependent on the stroke of the
vertical lifting jacks of the jetting-shoe control unit. After
cutting the slot, the computer turns off the high-pressure pump,
and then rotates or indexes the jetting-shoe assembly via the
program and horizontal axial movement of the work string and
jetting-shoe to a predefined location, and the computer goes into a
feed hold. The operator observes jetting-shoe location and then
turns on the high-pressure pump. After verification of a 4 to 7 bar
pressure drop, that indicates a hole has been blown through the
casing at the second location, the operator starts the computer and
slotting is begun in the opposite direction of the first slot by
the jetting-shoe control unit. A slot is cut up to 1.5 meters in
length (again, slot length is dependent on the stroke of the access
tool and can be any reasonable length) in that direction and the
computer turns off the high-pressure pump, rotates or indexes the
horizontal axial movement of the work string and jetting-shoe to a
predefined location and the computer goes into a feed hold. The
operator again starts the high-pressure pump, verifies hole
penetration through the casing by observing the high-pressure gage
in the cab or at the high-pressure pump and starts another vertical
slot in the opposite direction as the last slot. This process is
repeated until the casing slotting at that zone is completed. The
work string is then moved by the jetting-shoe control unit on top
of the well, either up or down, according to which zone is to be
slotted next, and another round of slotting starts again. This
sequence is repeated until the casing is slotted the length
required.
[0066] It is possible in eight to ten hours to cut 11 equally
spaced, 12 m length slots inside a 178 mm casing that is nested
inside of a 245 mm cemented casing and into the formation using one
jet-nozzle.
[0067] The inner most casing collars are not slotted to give
integrity of the slotted skeleton casing left in place after
slotting.
[0068] Empirical tests have shown at 1,200 m depth, 300 mm length
per minute cutting was achieved, pumping at 1,100 bar, 60 liters
per minute of 8% abrasive by weight coherent abrasive jet-fluid,
through a 1.2 mm diameter jet-nozzle to cut through a fluid filled
steel cemented 178 mm well casing 12 mm thick.
[0069] In an alternate embodiment, empirical tests have shown that
fluid pressure below 690 bar with varying orifice sizes and water
flow rates will provide sufficient energy and abrasion to cut
through the well bore casing or formation, but at a cost of
additional time to complete the project. As will be appreciated by
those skilled in the art, variations in the jet-nozzle orifice size
or the abrasive component utilized in the cutting apparatus fluid
slurry will generally necessitate an increase or decrease in the
fluid slurry flow rate as well as an increase or decrease in the
pressure required to be applied to the coherent abrasive-jet fluid
(slurry). Additionally, the time constraints attendant to the
specific application will also impinge upon the slurry flow rate,
pressure and orifice sizes selected for the specific application
undertaken.
[0070] As an additional example, in real world tests, with the
target and nozzle both under water, a 1.2 mm diameter nozzle
operating at 69 bar and 26 liters per minute abrasive-jet fluid,
cut through 1.5 mm thick metal from a distance of one meter.
[0071] One advantage of the present disclosure over the prior art
is that the attendant costs of cutting through the well bore casing
or formation will be relatively nominal as compared to the total
drilling costs. In addition, the present disclosure provides that
any additional costs of operation of the cutting apparatus may be
significantly offset by the decreased site and personnel costs.
[0072] The methods and systems described herein are not limited to
specific sizes or shapes. Numerous objects and advantages of the
disclosure will become apparent as the following detailed
description of the multiple embodiments of the apparatus and
methods of the present disclosure are depicted in conjunction with
the drawings and examples, which illustrate such embodiments.
[0073] A work-over-rig or a drill rig is utilized to attach a
jetting-shoe to the end of a tubing-work-string, which are inserted
into the annulus of the cased well bore to a point down hole in the
annulus, where a user programmable shape or window profile(s) are
to be abrasive-jet-fluid cut through the casing and cement, to
expose formation rock.
[0074] Next, air or other slips are set around the
tubing-work-string in the tubing rotator thereby suspending and
holding the tubing-work-string. Thus, allowing the shape or window
jetting-shoe control unit to be able to simultaneously move the
vertical axis and 360 degree horizontal rotary axis of the
tubing-work-string under computer program control,
[0075] The method for cutting user programmable shapes or window
profile(s) through down hole casing further includes inserting a
fluid-tube, that is fed from a coiled tubing unit and coiled tubing
injector head, into the bore of the work-string which is suspended
by the rotator and jack of the jetting-shoe control unit, so the
jet-nozzle attached to the end of the fluid-tube is fed through the
jetting-shoe to face the inner surface of the casing.
[0076] An operational cycle of the computer control unit is then
commenced, which positions the jetting-shoe and jet-nozzle into the
proper location for cutting the user programmable shapes or window
profile(s), which in turn engages the high-pressure pump and drives
the two-axis programmable computer servo controller unit at the
surface to generate the user programmable shape or window
profile(s) to cut through the casing or through a plurality of
metal casings of varying diameters stacked within each other and
sealed together with cement grout.
[0077] The computer further controls the coiled tubing unit and the
feed speed of the coiled tubing injector and depth location of the
jet-nozzle attached to the end of the fluid-tube. A co-ordinate
measuring of the cut shapes or window profile(s) is performed by
scanning with a magnetic proximity switch on the jetting-shoe that
faces the inner surface of the annulus. The cutting apparatus and
its attendant components are rotated and raised and lowered by the
jetting-shoe control unit under computer control.
[0078] The magnetic (or other) proximity switch senses the casing
in place, or the casing that has been removed by the
abrasive-jet-fluid, and activates a battery operated sonic
transmitter mounted in the jetting-shoe, which transmits a signal
to a surface receiver, that is coupled to the computer control unit
containing the data of the originally programmed casing cut shapes
or window profile(s) for comparison to the user programmed shape or
window profile(s).
[0079] FIG. 1 depicts a well bore lined with a casing 1. Casing 1
is typically cemented in the well bore by cement bond 2, wherein
cement bond 2 is surrounded by a formation 3. A jetting-shoe 5 is
illustrated in FIG. 1 with a jet nozzle 46 attached to the end of
fluid-tube 9. The jetting-shoe 5 is depicted with a threaded joint
33 attached at a lower end of a string of drill or
tubing-work-string 6. Drill pipe or tubing-work-string 6 and
jetting-shoe 5 are lowered into annulus 24 of the well at or near a
location where a shape or window profile(s) is to be cut and is
suspended by casing adaptor flange 7 in by tubing rotator 8.
[0080] FIG. 1 further depicts jetting-shoe 5 in position with a
fluid-tube 9 being fed into the drill or tubing-work-string 6 by a
coiled tubing injector head (not shown) from a coiled tubing reel
13 through the jetting-shoe 5. The fluid-tube 9 is transitioned
from a vertical to horizontal orientation inside of the
jetting-shoe 5 such that the jet-nozzle 46 is in disposed in
proximity to casing 1 that is to be cut. The reader should note
that although the drawings depict a well casing being cut into, the
target could very well be an impediment such as an extraction tool
or other equipment lodged in the casing.
[0081] The shape or window profile(s) are programmed into the
computer 11 via a graphical user interface (GUI) and the
high-pressure pump 19 is initiated when the operator executes the
run program (not shown) on the computer 11. The computer 11 is
directed by sub-programs and parameters inputted into the system by
the user. Additionally, previous cutting sessions can be stored on
the computer 11 via memory or on a computer readable medium and
executed at various job sites where the attendant conditions are
such that a previously implemented setup is applicable.
[0082] Fluid 21 to be pumped is contained in tank 22 and flows to a
high-pressure pump 19 through pipe 20. The high-pressure pump 19
increases pressure and part of the fluid flows from the
high-pressure pump 19 is diverted to flow pipe 18 and then into
fluid slurry control valve 17 and into abrasive pressure vessel 16
containing abrasive material 15. Typically a 10% flow rate is
directed via flow pipe 18 and fluid slurry control valve 17 to the
abrasive pressure vessel 16. The flow rate is capable of being
adjusted such that the abrasive will remain suspended in the fluid
21 utilized. In examples of predictive cutting times, the base line
flow was modulated to provide an abrasive concentration by weight
to fluid ratio of about 8%. The maintaining of an abrasive to
concentration fluid ratio is an important element in the present
disclosure as well as the type of abrasive, such as sand, Garnet,
various silica, copper slag, synthetic materials or Corundum are
employed.
[0083] The volume of fluid directed to the abrasive pressure vessel
16 is such that a fluid, often water, and abrasive slurry are
maintained at a sufficient velocity, such as 2.4 to 10 meters per
second through fluid-tube 9, so that the abrasive is kept in
suspension through the jet-nozzle 46. A velocity too low will
result in the abrasive falling out of the slurry mix and clumping
up at some point, prior to exiting the jet-nozzle 46. This
ultimately results in less energy being delivered by the slurry at
the target site.
[0084] Furthermore, a velocity too high will result in similarly
deleterious effects with respect to the energy being delivered by
the slurry at the target site. FIG. 6 This is because of the
stagnation region of a nozzle throat 47 being too long for the
fluid velocity inside the throat 47 of the nozzle 46.
[0085] FIG. 1 The abrasive material 15, such as sand garnet or
silica, is mixed with the high-pressure pump 19 fluid flow at
mixing valve 14. Mixing valve 14 further includes a venturi 36,
which produces a jet effect, thereby creating a vacuum aid in
drawing the abrasive water (slurry) mix. With the above-described
orientation the slurry exiting the jet-nozzle 46 can achieve high
velocities and be capable of cutting through practically any
structure or material.
[0086] The coherent abrasive-jet-fluid then flows through coiled
tubing reel 13 and down fluid-tube 9 and out jet-nozzle 46 cutting
the casing 1 and the cement bond 2 and the formation 3. Although
the drawings and examples refer to cutting or making a shape or
window profile in the well bore casing, it should be understood by
the reader that the present disclosure is not limited to this
embodiment an application alone, but is applicable and contemplated
by the inventors to be utilized with regard to impediments and
other structures as described above.
[0087] In an alternate embodiment an abrasive with the properties
within or similar to the complex family of silicate minerals such
as garnet is utilized. Garnets are a complex family of silicate
minerals with similar structures and a wide range of chemical
compositions and properties. The general chemical formula for
garnet is AB (SiO), where A can be calcium, magnesium, ferrous iron
or manganese; and B can be aluminum, chromium, ferric iron, or
titanium.
[0088] More specifically the garnet group of minerals shows
crystals with a habit of rhombic dodecahedrons and trapezohedrons.
They are nesosilicates with the same general formula,
A.sub.3B.sub.2(SiO.sub.4).sub.3. Garnets show no cleavage and a
dodecahedral parting. Fracture is conchoidal to uneven; some
varieties are very tough and are valuable for abrasive purposes.
Hardness is approximately 6.5-9.0 Mohs; specific gravity is
approximately 2.1 for crushed garnet.
[0089] Garnets tend to be inert and resist gradation and are
excellent choices for an abrasive. Garnets can be industrially
obtained quite easily in various grades. In the present disclosure,
empirical tests performed utilized an 80-grit garnet.
[0090] A person of ordinary skill in the art will appreciate that
the abrasive material 15 is an important consideration in the
cutting process and the application of the proper abrasive with the
superior apparatus and method of the present disclosure provides a
substantial improvement over the prior art.
[0091] The cutting time of the abrasive-jet-fluid is dependant on
the material and the thickness cut. The computer 11 processes input
data and telemetry and directs signals to servomotor 10 and
servomotor 12 to simultaneously move the tubing-work-string rotator
8 and tubing-work-string jack 25 to cut the shapes or window
profile(s) that have been programmed into the computer 11.
Predetermined feed and speed subprograms are incorporated into the
software to be executed by computer 11 in the direction and
operation of the cutting apparatus.
[0092] Any excess fluid is discharged up annulus 24 through choke
23. The steel that is cut during the shaping or cutting process
drops below the jetting-shoe 5 and can be caught in a basket (not
shown) hanging below or be retrieved by a magnet (not shown)
attached to the bottom of the jetting-shoe 5 if required. If
desirable the steel or other material (e.g. formation rock, cement,
tools, etc.) may be allowed to fall down into the open hole below
the cut.
[0093] Tubing-work-string jack 25 is driven in the vertical axis by
a worm gear 27, depicted in FIG. 2, which is powered by a servo
motor (not shown) that drives a ball screw 28. The
tubing-work-string jack 25 is bolted on the wellhead 37 at flange
30. The tubing-work-string jack 25 is counterbalanced by the
hydraulic fluid 29 that is under pressure from a hydraulic
accumulator cylinder under high-pressure 31. The rotator is
attached on the top of the tubing-work-string jack 25 at flange
26.
[0094] The jetting-shoe 5, as illustrated in FIG. 3, is typically
made of 316 stainless steel or similarly resilient material. The
jetting-shoe 5 is connected to the tubing-work-string 6 with
threads 33. Stabbing guide 35, a part of the jetting-shoe 5, is
disposed inside of tubing-work-string string 6 that supports the
guiding of the flow-tube 9 into the jetting-shoe 5. The flow-tube 9
transitions from a vertical axis to a horizontal axis inside of the
jetting-shoe 5. The jet-nozzle 46 is coupled to the fluid-tube 9
and disposed such that it faces the surface face of the well-bore
casing and the coherent abrasive-jet-fluid exits the jet-nozzle 46
and cuts the casing 1.
[0095] A battery operated sonic transmitter and magnetic proximity
switch, not shown, are installed in borehole 34 of the jetting-shoe
5 to allow scanning of the abrasive-jet-fluid cuts through the
casing 1. Telemetry is transmitted via a signaling cable to
computer 11. The signaling cable, not shown, may be of a shielded
variety or optical in nature, depending on the design constraints
employed.
[0096] In another embodiment a battery operated sonic transmitter
and magnetic proximity switch, not shown, are installed in borehole
34 of the jetting-shoe 5 to allow scanning of the
abrasive-jet-fluid cuts through the casing 1. Telemetry is
transmitted via sound waves to computer 11.
[0097] In another embodiment based on a 15,000-PSI pressure
delivered to the jet-nozzle 46 comprising a 1.2 mm diameter
orifice, the jet-nozzle 46 is made of boron carbide or silicon
carbide.
[0098] For instance, the casing material to be cut is a variable,
as well as the diameter of the casing. In one instance the diameter
of the casing could be 101 mm and another 1,200 mm in diameter.
[0099] Based on these constraints and many others, the cutting
times desired, cutting rate attainable, jet-nozzle size orifice,
abrasive material on hand or selected, pressure to be delivered at
the work site, as well as safety concerns and the depletion of the
equipment deployed are incorporated into the final calculations and
either programmed or inputted into the computer 11.
[0100] Additional empirical tests have demonstrated that in one
embodiment of the present disclosure the operational range
contemplated is between approximately 690 bar and 2,750 bar with a
nominal working range of approximately 1,100 bar.
[0101] FIGS. 4A and 4B depict a rotator-casing bowl 8, such as R
and M Energy Systems heavy-duty model RODEC RDII, secured on top of
tubing-work-string string jack 25. The tubing-work-string 6 is
inserted through (see FIG. 4B) casing adaptor flange 7, which is
further disposed on top of pinion shaft 32. Pinion shaft 32 is
adapted to secure and suspend the tubing-work-string 6 within the
annulus 24. The 360-degree rotary movement of the
tubing-work-string 6 is accomplished by the pinion shaft 32, which
is powered by servomotor 10. The present disclosure may be embodied
in other specific forms without departing from its spirit or
essential characteristics.
[0102] An exploded view of the novel nozzle configuration of an
aspect of the present disclosure is depicted in FIG. 5. A helix or
spring 40 is placed in a high-pressure hose 49 (See FIG. 6) and
creates rotation of the fluid as the cutting fluid passes from the
proximate end 41 to the distal end 42 of the helix 40. It should be
noted that the helix or spring 40 could be of any configuration
that increases the RPM of the cutting fluid as it pass from the
proximate end 41 to the distal end 42 of the helix 40. In this
disclosure the term helix is not meant to limit the invention in
any sense. A helix is contemplated by the present invention to be
any structure that is capable of being inserted into the
high-pressure hose 49 and provide a RPM increase as stated
above.
[0103] The helix or spring 40 can be comprised of a single piece of
metal resembling a drill bit or be a wire coiled into a spring, but
is not limited to these configurations. A person of ordinary skill
in the art will appreciate that based on the principles of fluid
mechanics that varying the helix shape may be necessitated to
provide superior efficiencies and energy transfer based on the
cutting fluid involved and the desired working cutting pressures.
An aspect of the present invention is to determine the optimum
parameters necessary to produce such results and to vary the
components and their dimensions and compositions to achieve the
desired yield.
[0104] Typically, the helix 40 is comprised of, but not limited to,
ceramic, or silicon carbide, or tungsten carbide or boron carbide,
or other abrasive resistant material.
[0105] In an aspect of the present invention the helix 40 is
approximately 25 mm in length. Furthermore, since the
high-pressure-hose 49 size can vary and the working environment can
change, i.e. well bore size changes from a larger to smaller bore
diameter, the length and composition of the helix may necessitate
changes to accommodate them down the bore-hole.
[0106] The helix 40 is such that from the proximate end 41 to the
distal end 42 the turn ratio of the helix varies from 90 degrees to
360 degrees over a ratio length distance of degree turn to length
of the helix. The ratio is determined based on the cutting fluid
velocity passing the helix and the resulting rotating jet fluid
velocity desired of the exiting fluid jet stream required for
increased distance cutting through water by exceeding the water
pressure vapor of the water the abrasive-fluid-jet stream is
traveling through, allowing the abrasive-fluid-jet stream to travel
through the generated water vapor gas. For instance in a cutting
fluid slurry including garnet the outer rotating vortex fluid
velocity has to be approximately 70 meters per second depending on
water depth, density and temperature to exceed the water vapor
pressure. The guiding principle behind the turn ratio of the helix
40 is to create a vortex after the abrasive-fluid jet-nozzle distal
end 45 and lower pressure, whereby the cutting length of the
exiting abrasive-jet-fluid, is increased by the jet-fluid vortex
stream.
[0107] Returning to the embodiment depicted in FIG. 5, the hose 49
is attached to a nozzle holder assembly 44 via a ferrule 47 (See
FIG. 6). A jet-nozzle 46, comprised of a hard material, such as but
not limited to silicon carbide or boron carbide steel or similar
material, is inserted into the nozzle holder assembly 44. A nozzle
end retainer 48 is then placed over the distal end 45 of the
jet-nozzle 46 and secured (e.g. screwed) in place.
[0108] FIG. 6 illustrates an assembled view of the hose-nozzle
assembly of one embodiment. Hose 49 is a high-pressure type hose,
typically having an inner-plastic polyamide type lining. In an
aspect of the present invention the hose 49 is a 12 mm I.D. hose
produced by Parker Polyflex. The hose 49 is capable of sustaining
high-pressure fluid in the 1,300 bar range.
[0109] By way of example, the abrasive cutting fluid traverses the
hose 49 and engages the proximal end 41 of helix 40 at about 8.8
meters per second and is split into two flows around the helix 40
and begins to rotate about the helix 40. As the
abrasive-cutting-fluid progresses beyond the distal end 42 of helix
40 the abrasive cutting fluid is now rotating and has increased in
velocity to about 26.9 meters per second as the helix 40 area is
less than the area of the hose 49 before the helix 40. Stepping up
the velocity of the motive fluid from the hose 49 through the helix
40 gives time for the abrasive particles to accelerate to about 80%
of the motive fluid velocity. Just as one uses the on ramp to
accelerate to the traffic flow on an expressway, there is a time
factor for acceleration of the abrasive particles not considered by
others. The resultant rotation of the abrasive cutting fluid
exiting the jet-nozzle 46 creates a vortex that increases the outer
velocity of the abrasive cutting fluid thereby decreasing the
pressure aiding in cavitation bubble formation. In an aspect of the
present invention the increase in the cutting fluid velocity is
increased multiple times and theoretically higher velocity by the
converging-diverging jet-nozzle 46 to approximately 700 meters per
second exit speed of the motive fluid. As the
abrasive-cutting-fluid exits helix 40, the abrasive cutting fluid
has increased in velocity because of the smaller area through the
helix 40 enters into a smaller diameter 37 cavity in the nozzle
retainer 44 where the two split flows from the helix 40 are merged
together prior to the jet-nozzle 46. The velocity then increases as
the abrasive-cutting-fluid passes through jet-nozzle 46 according
to the diameter of the jet-nozzle 46 orifice and the volume of the
motive fluid dragging along the abrasive particles to exit the
jet-nozzle 46 at high velocity. Additionally, as the
abrasive-cutting-fluid traverses across the helix 40, the RPM of
the abrasive-cutting-fluid increases from zero at the proximate end
41 of the helix 40 to about 30,000 RPM after the distal end 42 of
the helix 40. The velocity of the rotating abrasive-fluid flowing
from the distal end 42 of the helix 40 has increased because of the
helix's 40 smaller flow area than the hose's 49 flow area. After
the rotating abrasive-fluid exits the distal end 42 of the helix
40, its velocity again increases as it passes through the smaller
inside diameter 39 of nozzle holder 44. The rotating
abrasive-motive fluid flow's huge velocity increase is because of
the converging input taper of the proximate end 43 of the
jet-nozzle 46 and the 1.2 mm orifice diameter of the jet-nozzle 46
to a velocity about 700 meters per second. The abrasive particles
achieve about 80% of the motive fluid flow or about 560 meters per
second.
[0110] The jet-nozzle 46 is tuned by measuring the pressure at the
jet-nozzle 46 proximate entrance region 43 using a pressure gage
and mass flow rate with a transit time ultrasonic flow meter across
the jet-nozzle throat and trimming the nozzle distal exit end
length 45 until there is a decrease of back pressure at the
jet-nozzle 46 proximate entrance region 43 and increase flow rate
through the jet-nozzle 46. After the maximum jet velocity is
achieved, any additional length of the nozzle throat causes
resistance from the effect of the jet-nozzle throat wall friction
due to a longer than necessary throat length. By shorting the
jet-nozzle 46 length, the jet-nozzle can deliver the maximum force
possible from inside of the jet-nozzle 46 to the exit or distal end
45 of the jet-nozzle 46. The length of jet-nozzle 46 is about 10
times the orifice diameter of the jet-nozzle 46 excluding the
length of jet-nozzle 46 converging taper proximate entrance 43.
Most existing jet-nozzles throat lengths are about 40 times the
orifice diameter, which may decrease the energy transferred from
the jet-nozzle to the intended target because of jet-nozzle throat
wall friction, where the maximum jet-nozzle velocity has occurred
upstream in the nozzle throat before the exit or distal end of the
jet-nozzle.
[0111] In one embodiment, the distal end 45 of jet-nozzle 46 is
tapered to about 60-degrees. This diverging tapering is determined
such that the transition from the high velocity of the abrasive
cutting fluid from the end of the jet-nozzle 46 to a target 58 via
the abrasive-cutting-fluid 56 can achieve maximum cutting length.
In an aspect of the present invention the tapering 50 is
approximately 30-degrees. The 60-degree beveling of the distal end
45 of jet-nozzle 46 is configured for diverging and increasing the
velocity of the motive fluid to transfer the maximum amount of
energy to the target 58.
[0112] As further depicted in FIG. 6, the abrasive-cutting-fluid 56
exiting the jet-nozzle 46 expands to a fan 54 to allow the complete
nozzle hose assembly to pass through an eroded hole 51 through
target 58 if desired. A void 52 is created in area 52 between the
fan 54 and the nozzle end retainer 48. This void 52 aids in the
cutting of the target by preventing the shearing of the exiting
abrasive-jet-fluid 56 from the jet-nozzle 46. Although not to scale
in the figure, the vortex creates a cutting action that creates an
opening in the target 58 about 32 mm in diameter which is greater
than the nozzle retainer 48 diameter (e.g. about 25 mm). One can
observe the abrasive-jet-fluid vortex cutting by viewing a target
that is not completely cut where a slug 59 remains until the cut is
completed.
[0113] In Empirical tests, a 50 mm diameter hole was drilled 5
meters deep through wet soil in two minutes, with the jet-nozzle 46
pointing toward the ground with the hose 49 and jet-nozzle 46
two-feet from the ground while being suspended by two 12 mm bungee
cords. The jet-nozzle 46 was stable and had no observed whip.
[0114] As depicted in FIG. 7, once the abrasive-cutting-fluid
stream 56 penetrates the target the vortex 52 begins eroding away
any material on the rear of target 58. The darkened regions 53
represent the vortex and the action of the abrasive cutting fluid
on the backside of the target. This cyclonic action also creates a
hole in the target of greater diameter than the
abrasive-cutting-fluid stream 56, as previously stated. Furthermore
the cyclonic action removes cement and produces a backpressure on
the rear of the target and assists in the removal of any pattern
cut from the target material (e.g. well bore casing).
[0115] FIG. 7 depicts an exemplary view of the novel cutting nozzle
in operation. As can be seen in FIG. 7, a cutout design is
depicted, wherein the control system has mapped out and cut the
predetermined design, here a rectangular pattern, in the well
casing bore. As can be seen in the pattern, the edges are clean as
if machined and are substantially perpendicular to the cut. The
cyclonic action of the cutting fluid as produced by the novel
nozzle configuration cleans the back surface of the bore
casing.
[0116] The cutting continues in the rock or substrate region
extending further into the rock or substrate formation making small
pebbles out of the solid formation rock. Without any additional
lateral movement the present invention can cut approximately a one
meter pattern into the surrounding strata in 5 minutes or less,
depending on the strata composition. In the exemplary view and case
the strata was a standard rock formation encountered typical in
oilfields.
[0117] An aspect of the present invention contemplates any
determined turns ratio from the proximate end 41 to the distal end
42 of the helix 40 that increases cutting fluid velocity and aides
in delivering the maximum amount of cutting energy to the
target.
[0118] Although described specifically as cutting a greater
diameter than the nozzle retainer 48, the jet-nozzle can also
perform very precise cutting with minor changes such as increasing
the length of jet-nozzle 46 to decrease fan width 56.
[0119] FIG. 8 depicts an alternate embodiment of the jet-nozzle 46
and the hose-nozzle assembly. In this embodiment, the helix 40 is
inserted into a sleeve 60. The sleeve 60 could be made using a
variety of materials including nylon. The outer diameter (OD) of
the helix 40 and the inner diameter (ID) of the sleeve 60 are such
that the helix 40 will not rotate within the sleeve 60 even when
the abrasive cutting fluid traverses across the helix 40. The
sleeve 60 is inserted into the hose 49, which is also a tight
enough fit to keep the sleeve 60 from rotating within the hose
49.
[0120] A ferrule 47 is placed onto the hose 49 and the hose 49 is
inserted over the nozzle holder assembly 44. The ferrule 47 is
crimped to secure the hose 49 to the nozzle holder assembly 44. It
is important to ensure the crimp is sufficient to keep the nozzle
holder assembly 44 attached to the hose 49 under pressure.
[0121] After crimping the ferrule 47 onto the hose 49 a hole gage
is inserted into the end of the nozzle holder 44 and the inside
diameter 39 of the nozzle holder assembly 44 should be about 0.7 mm
smaller inside diameter 39 than before the ferrule 47 was crimped
to insure that the nozzle holder assembly 44 will hold the
high-pressure safely. The total crimp length is about one-third the
length of a normal commercial fitting and is necessarily short to
allow the nozzle assembly 44, with the nozzle retainer 48 attached,
to turn in a short radius inside smaller well bores in order to
face the target to be cut.
[0122] The smaller inside diameter 39 of the nozzle holder assembly
44 also increases the abrasive-cutting-fluid 56 velocity before
entering the converging input taper of the jet-nozzle 46 proximate
end 43.
[0123] Stair stepping the abrasive-cutting-fluid 56 velocity, first
through the helix, 40 then the nozzle holder assembly, 44 and the
converging jet-nozzle 46 gives acceleration time for the abrasive
particles to come closer to the velocity of the motive fluid. The
velocity of the abrasive-cutting-fluid 56 exiting the jet-nozzle 46
extends the distance a target may be cut from the jet-nozzle exit
distal end 45.
[0124] Continuing with this embodiment, the jet-nozzle 46 is
inserted into the nozzle holder assembly 44 and the nozzle holder
assembly 44 is secured into the nozzle end retainer 48. The sleeve
60, and consequently the helix 40, are arranged close (or even
touching) the proximate end 43 of the nozzle holder assembly 44.
This placement permits the jet nozzle to operate in narrow well
bore casings (e.g. 101 mm).
[0125] Still continuing with this embodiment, the nozzle end
retainer 48 is angled at about 30 degrees 50 (although other angles
could also be employed) in a conical shape. The jet-nozzle 46
extends into the base of this "cone" and extends substantially to
the distal end 45 of the nozzle end retainer 48.
[0126] The jet-nozzle 46 is a converging-diverging nozzle that
allows the abrasive fluid discharge velocity to create cavitations
in water.
[0127] Cavitation is a phenomenon known to engineers in the field
of fluid dynamics wherein small cavities of a partial vacuum form
in a liquid substance wherein the cavities then rapidly collapse.
In one example, cavitation occurs when water is forced to move at
extremely high speed (e.g. in fluid flows around an obstacle such
as a rapidly rotating propeller). In such an example, the pressure
of the fluid drops due to its high speed flows (Bernoulli's
principle). When the pressure drops below its saturated vapor
pressure, it creates a plurality of cavities in the water-hence the
term cavitation. The cavities can take on a number or forms and
configurations that all consist of regions or bubbles of a partial
vacuum, i.e., very low pressure gas phase water.
[0128] The high velocity rotating jet exiting from the nozzle
creates a vortex, whereby cavitation gas bubbles are generated
along the downstream path of the abrasive/jet flow, by the rapid
fluid pressure drop due to the high velocity and rotation of the
water jet stream (Bernoulli's principle). The resulting downstream
gas pathway created by the cavitation gas in the water, allows the
abrasive/jet stream maximum possible impact momentum onto a
downstream under water steel target 600 mm away from the
nozzle.
[0129] In real world under-water tests, the abrasive/jet stream (80
grit size abrasive media) traveling through the gas pathway created
by the cavitation gas in the water, impacting a downstream steel
target, crushes the 80 grit size abrasive media into smaller
abrasive media, where the resulting crushed abrasive media will
pass through a USS 200 mesh.
[0130] Therefore, as the coherent abrasive laden cutting-fluid
traverse along the hose 49 under pressure, the abrasive cutting
fluid is forced across the helix 40. Because the helix 40 is
disposed within the sleeve 60, the abrasive-cutting-fluid's path is
further constricted which raises the abrasive-cutting-fluid's
velocity as it traverses across the helix 40. Additionally, as the
abrasive cutting fluid traverses across the helix 40, the helix 40
makes the fluid rotate creating a vortex as the abrasive/fluid
exits the jet-nozzle 46. As the abrasive cutting fluid traverses
from the proximate end 43 to the distal end 45 of the jet-nozzle
46, the abrasive-cutting-fluid's path is further restricted and the
velocity is consequently increased by the nozzle converging taper.
As the abrasive-cutting-fluid exits the distal end 45 of the
jet-nozzle 46, the abrasive cutting fluid is traveling at about 700
meters per second.
[0131] FIG. 9. Although described specifically as cutting a greater
diameter than the cutting nozzle, the nozzle can also perform very
precise cutting with minor changes such as increasing the length of
jet-nozzle 46 to decrease abrasive-jet width 56.
[0132] At speeds above about 70 meters per second cavitation occurs
in water. Cavitation is the phenomenon where small cavities (e.g.
bubbles) of a partial vacuum form in a liquid and then rapidly
collapse. Cavitation is generally a very destructive force and this
is the phenomenon that greatly contributes to existing nozzles
destroying themselves within a matter of minutes (similar to
propeller blades).
[0133] The abrasive-fluid is compressed about 5% at 1,100 bar and
that denser compressed water expands when the abrasive fluid exits
the nozzle helping create a pressure change that might enhance the
formation of water vapor.
[0134] Additionally, it is believed that the extreme distances the
presently disclosed nozzle can cut are accomplished by the vortex
and, when disposed within a liquid, supercavitation. In air, the
abrasive-jet fluid from the vortex nozzle has cut through steel 4.5
meters from the nozzle end. It is believed that this is
accomplished because the vortex does not allow the air to shear the
jet-force energy from the abrasive-jet-fluid stream, much like a
rotating tornado vortex allows the high velocity jet stream energy
to travel thousands of feet down to the earth. Supercavitation is a
theory whereby as an object travels through a liquid where
cavitation has created a large bubble of gas surrounding the
object. This drastically increases the distance an object can
travel through the liquid because the object is traveling in gas
instead of the liquid. It is believed that such a gas bubble is
created when the abrasive cutting fluid exits the jet-nozzle 46 at
high speed.
[0135] The described embodiments are to be considered in all
respects only as illustrative and not restrictive. It will be
apparent to those skilled in the art that various modifications and
variations can be made in the System and Apparatus for Jet-Fluid
Cutting Nozzle of the present disclosure and in construction of
this disclosure without departing from the scope or intent of the
disclosure.
[0136] Other embodiments of the disclosure will be apparent to
those skilled in the art from consideration of the specification
and practice of the disclosure disclosed herein. It is intended
that the specification and examples be considered as exemplary
only, with a true scope and spirit of the disclosure being
indicated by the following claims.
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