U.S. patent application number 14/547231 was filed with the patent office on 2015-05-28 for power retrieving tool.
The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Erik P. Eriksen.
Application Number | 20150144335 14/547231 |
Document ID | / |
Family ID | 53180157 |
Filed Date | 2015-05-28 |
United States Patent
Application |
20150144335 |
Kind Code |
A1 |
Eriksen; Erik P. |
May 28, 2015 |
POWER RETRIEVING TOOL
Abstract
Apparatuses and methods for retrieving a tool or bottom hole
assembly. The apparatus may include a latching device that couples
to a tool or bottom hole assembly to be retrieved and at least one
seal extending radially from the apparatus to engage an inner
diameter of a tubular, such as a casing string. A pump inlet is
disposed in or through an outer surface of the apparatus uphole of
the at least one seal. A pump outlet is disposed in or through an
outer surface of the apparatus downhole of the at least one seal.
The apparatus may also include a pump for pumping a drilling fluid
from the pump inlet to the pump outlet in order to generate a
differential pressure across the at least one seal and provide a
hydraulic force to effect retrieval of the tool or bottom hole
assembly.
Inventors: |
Eriksen; Erik P.; (Calgary,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
Sugar Land |
TX |
US |
|
|
Family ID: |
53180157 |
Appl. No.: |
14/547231 |
Filed: |
November 19, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61908605 |
Nov 25, 2013 |
|
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Current U.S.
Class: |
166/250.01 ;
166/244.1; 166/301; 166/66; 166/98 |
Current CPC
Class: |
E21B 7/20 20130101; E21B
10/66 20130101 |
Class at
Publication: |
166/250.01 ;
166/98; 166/66; 166/301; 166/244.1 |
International
Class: |
E21B 31/12 20060101
E21B031/12; E21B 47/06 20060101 E21B047/06; E21B 23/14 20060101
E21B023/14; E21B 33/126 20060101 E21B033/126; E21B 23/00 20060101
E21B023/00 |
Claims
1. An apparatus for retrieving one of a tool and a bottom hole
assembly, comprising: a latching device arranged and designed to
couple to a tool or bottom hole assembly to be retrieved; at least
one seal extending radially from the apparatus and configured to
engage an inner diameter of a tubular; a pump inlet disposed in an
outer surface of the apparatus uphole of the at least one seal; a
pump outlet disposed in an outer surface of the apparatus downhole
of the at least one seal; and a pump for pumping a drilling fluid
from the pump inlet to the pump outlet to generate a differential
pressure across the at least one seal and provide a hydraulic force
to effect retrieval of the tool or bottom hole assembly.
2. The apparatus of claim 1, wherein the at least one seal includes
a downward facing packer cup configured to sealingly engage the
inner diameter of the tubular during the retrieval operation.
3. The apparatus of claim 1, wherein the at least one seal includes
an upward facing packer cup configured to sealingly engage the
inner diameter of the tubular during and allow the apparatus to be
pumped downhole.
4. The apparatus of claim 1, further comprising an electric
wireline configured to provide at least one of the following: power
to an electric motor to operate the pump; communications to a
control module for monitoring or controlling retrieval operations;
and application of additional upward force to the apparatus.
5. The apparatus of claim 4, wherein the control module has
external wickers thread.
6. The apparatus of claim 1, further comprising a pressure
measurement system arranged and designed to determine a
differential pressure across the at least one seal.
7. A method of retrieving a tool or a bottom hole assembly,
comprising: coupling a retrieval apparatus to one of a tool and a
bottom hole assembly to be retrieved, the retrieval apparatus
having at least one seal extending radially therefrom and
configured to sealingly engage an inner diameter of a tubular; and
pumping fluid from an inlet of the retrieval apparatus positioned
uphole of the at least one seal to an outlet of the retrieval
apparatus positioned downhole of the at least one seal to generate
a differential pressure across the at least one seal and provide a
hydraulic force to effect retrieval of the tool or bottom hole
assembly.
8. The method of claim 7, further comprising deploying the
retrieval apparatus downhole and engaging a drill lock assembly or
tool lock assembly.
9. The method of claim 8, wherein the deploying comprises pumping
the retrieval apparatus downhole.
10. The method of claim 7, wherein the tubular is a casing string
and the method further comprising sealingly engaging an inner
diameter of the casing string via the at least one seal.
11. The method of claim 7, further comprising pulling a wireline
coupled to the retrieval apparatus to provide additional upward
force to the retrieval apparatus.
12. The method of claim 7, further comprising at least one of
measuring and controlling the differential pressure.
13. The method of claim 7, further comprising adding fluid to the
casing string above the retrieval apparatus.
14. A method of circulating fluids during a wireline retrieval
operation, comprising: flowing fluid through a casing string to an
inlet of a retrieval apparatus; and pumping fluid from the inlet to
an outlet of the retrieval apparatus to: generate a differential
pressure across the retrieval apparatus and provide a hydraulic
force to effect retrieval of a tool or a bottom hole assembly; and
circulate fluid from the casing string into a casing string
annulus.
15. The method of claim 14, further comprising withdrawing fluid
from the casing string annulus.
16. The method of claim 14, further comprising at least one of
measuring and controlling the differential pressure.
17. The method of claim 16, wherein controlling the differential
pressure includes adjusting a fluid pumping rate from the inlet to
the outlet.
18. The method of claim 14, further comprising pulling a wireline
coupled to the retrieval apparatus to provide additional upward
force to the retrieval apparatus.
19. The method of claim 14, further comprising reciprocating the
casing string while performing the wireline retrieval
operation.
20. The method of claim 14, further comprising when the retrieval
tool is at surface: monitoring a pressure of the well; when static,
disconnecting surface pressure control equipment from an upper end
portion of the casing string; and recovering the tool or the bottom
hole assembly.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Application 61/908,605, filed, Nov. 25, 2013, the entirety of which
is included by reference.
FIELD OF THE INVENTION
[0002] Aspects relate to casing while drilling for downhole
applications. More specifically, aspects relate to a power
retrieving tool for casing drilling applications.
BACKGROUND
[0003] Casing-while-drilling is a technique that involves running a
casing simultaneously with drilling a wellbore or borehole. The
operator locks a bottom hole assembly to the lower end portion of
the casing. The bottom hole assembly has a pilot drill bit and a
reamer for drilling the borehole as the casing is lowered into the
earth. The operator pumps drilling mud or fluid down the casing
string, which returns up the annulus surrounding the casing string,
along with cuttings from the drilling operation. The operator may
rotate the casing via the bottom hole assembly. The operator may
employ a mud motor that is powered by the downward flowing drilling
mud or fluid and that rotates the drill bit.
[0004] When the total depth has been reached, unless the drill bit
is to be cemented in the well, the operator will want to retrieve
the drill bit and related bottom hole assembly (one or more of an
under reamer, downhole motor, directional drilling tools, MWD
and/or LWD tools) through the casing string and install a cement
valve for cementing the casing string. Further, the bottom hole
assembly may need to be retrieved through the casing string prior
to reaching total depth to replace the drill bit and/or under
reamer or repair instruments associated with the bottom hole
assembly.
[0005] One retrieval method uses a wireline retrieval tool that is
lowered on wireline into engagement with the bottom hole assembly.
Wireline alone has a limited pulling capacity; wireline combined
with a tractor arrangement has low speed. During wireline
retrieval, an operator pulls upward on the wireline to retrieve the
bottom hole assembly. While this is a workable solution in many
cases, in some wells, the force to pull loose the bottom hole
assembly and retrieve it to the surface may be too high, resulting
in breakage of the cable.
[0006] In another method, the operator reverse circulates to pump
the bottom hole assembly back up the casing. Reverse out systems
operate at increased bottom hole pressure or use a lighter fluid
inside the tubular. One concern about reverse circulation is that
the amount of pressure to force the bottom hole assembly upward may
be damaging to the formation via the open borehole. The pressure
applied to the annulus of the casing may break down certain
formations, causing lost circulation or drilling fluid flow into
the formation. This technique may also cause formation fluid to
flow into the drilling fluid and be circulated up the casing
string.
SUMMARY
[0007] This summary is provided to introduce a selection of
concepts that are further described below in the detailed
description. This summary is not intended to identify key or
essential features of the claimed subject matter, nor is it
intended to be used as an aid in limiting the scope of the claimed
subject matter.
[0008] Implementations of apparatuses and methods for retrieving a
tool or bottom hole assembly are disclosed. The apparatus may
include a latching device that couples to a tool or bottom hole
assembly to be retrieved and at least one seal extending radially
from the apparatus to engage an inner diameter of a tubular, such
as a casing string. A pump inlet is disposed in or through an outer
surface of the apparatus uphole of the at least one seal. A pump
outlet is disposed in or through an outer surface of the apparatus
downhole of the at least one seal. The apparatus may also include a
pump for pumping a drilling fluid from the pump inlet to the pump
outlet in order to generate a differential pressure across the at
least one seal and provide a hydraulic force to effect retrieval of
the tool or bottom hole assembly.
[0009] The method of retrieving a tool or bottom hole assembly,
such as through a casing string in a casing-while-drilling
operation, may include latching or coupling a retrieval apparatus
to a tool or a bottom hole assembly to be retrieved, the retrieval
apparatus having at least one seal extending radially therefrom and
arranged to sealingly engage an inner diameter of a tubular, such
as a casing string. The method may also include pumping fluid from
an inlet of the retrieval apparatus positioned uphole of the at
least one seal to an outlet of the retrieval apparatus positioned
downhole of the at least one seal to generate a differential
pressure and provide a hydraulic force to effect retrieval of the
tool or bottom hole assembly.
[0010] In another implementation, the method of retrieving a tool
or bottom hole assembly may involve circulating fluids during a
wireline retrieval operation. Such method may include flowing fluid
through a casing string to an inlet of a retrieval apparatus. The
method may also include pumping fluid from the inlet to an outlet
of the retrieval apparatus to generate a differential pressure
across the retrieval apparatus and provide a hydraulic force to
effect retrieval of a tool or a bottom hole assembly. The method
may further include circulating fluid from the casing string into a
casing string annulus.
BRIEF DESCRIPTION OF DRAWINGS
[0011] So that the recited features may be understood in detail, a
more particular description, briefly summarized above, may be had
by reference to one or more implementations, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings are illustrative implementations, and
are, therefore, not to be considered limiting of its scope.
[0012] FIG. 1 is a schematic view illustrating a drilling system
for employing apparatuses and/or practicing methods according to
one or more implementations disclosed herein.
[0013] FIG. 2 illustrates one implementation of a drill lock
assembly.
[0014] FIG. 3 illustrates a power retrieving tool according to one
or more implementations disclosed herein.
[0015] FIG. 4 illustrates a power retrieving tool according to one
or more implementations disclosed herein coupled to a drill lock
assembly.
[0016] FIG. 5 illustrates a power retrieving tool according to one
or more implementations disclosed herein.
[0017] FIG. 6 illustrates a sectioned part of a power retrieving
tool according to one or more implementations disclosed herein.
[0018] FIG. 7 is a schematic view illustrating a retrieval
operation according to one or more implementations disclosed
herein.
DETAILED DESCRIPTION
[0019] Referring to FIG. 1, a borehole or wellbore 11 is shown
being drilled into a subterranean formation. The bore as
represented by borehole 11 is not limited to a bore into a
subterranean formation but may be a bore drilled into any drillable
material. Further, the bore as represented by borehole 11 may be
disposed in any orientation, such as vertical, horizontal or
therebetween. A casing string 13 is lowered into borehole 11. An
annulus 15 is located between the sidewall of borehole 11 and
casing string 13. One or more strings of casing 17 have already
been installed and cemented in place by cement 18. For convenience,
FIG. 1 shows one string of casing 17. Annulus 15 thus extends from
the bottom of casing string 13 up the annular space between casing
string 13 and casing 17.
[0020] A wellhead assembly 19 is located at or near the surface (or
at or near the sea floor for an offshore wellbore). Wellhead
assembly 19 will differ from one drilling rig to another, but as
shown has a blowout preventer 21 (BOP) that is capable of closing
and sealing around casing string 13. An annulus outlet flow line 22
extends from wellhead assembly 19 at a point above BOP 21. An
annulus inlet flow line 23 extends from wellhead assembly 19 from a
point below BOP 21. As illustrated in FIG. 1, a valve 61 and a flow
meter 63 are also located in annulus inlet flow line 23. Choke
valves and other components may also be disposed proximate the
surface.
[0021] Casing string 13 extends upward through an opening in rig
floor 25 that has a set of slips (not shown). A casing string
gripper 27 engages and supports the weight of casing string 13 and
is also capable of rotating casing string 13. Casing string gripper
27 may grip the inner side of casing string 13, as shown, or it may
alternately grip the outer side of casing string 13. Casing string
gripper 27 has a seal 29 that seals to the interior of casing
string 13. Casing string gripper 27 is secured to a top drive 31,
which moves casing string gripper 27 up and down the derrick (not
shown). A flow passage 33 extends through top drive 31 and casing
gripper 27 for communication with the interior of casing string
13.
[0022] A hose 35 couples to the upper end portion of flow passage
33 at top drive 31. Hose 35 is in fluid communication with a
discharge port 36 of a mud pump 37. Mud pump 37 may be a
conventional pump, which may have reciprocating pistons. A valve 39
is located at outlet 36 for selectively opening and closing
communication with hose 35. The drilling fluid or mud circulation
system includes one or more mud tanks 41 that hold a quantity of
drilling fluid or mud 43. The circulation system also has screening
devices (not shown) that remove cuttings from drilling fluid 43
returning from borehole 11 via annulus outlet flow line 22. Mud
pump 37 has a flow line inlet 45 that couples to mud tank 41 for
receiving drilling fluid 43 after cuttings have been removed. A
valve 46 selectively opens and closes the flow from mud tank 41 to
an inlet of mud pump 37. A centrifugal charging pump (not shown)
may be mounted in flow line 45 for supplying drilling fluid 43 to
mud pump 37.
[0023] A bottom hole assembly 47 is shown located at the lower end
portion of casing string 13. Bottom hole assembly 47 may include a
drill lock assembly 49 that has movable dogs 51 that engage an
annular recess in a sub near the lower end portion of casing string
13 to lock bottom hole assembly 47 in place. Drill lock assembly 49
also has keys that engage vertical slots for transmitting rotation
of casing string 13 to bottom hole assembly 47. Dogs 51 could be
eliminated, with the bottom hole assembly 47 retained at the lower
end portion of casing string 13 by drilling fluid pressure in
casing string 13. An extension pipe 53 extends downward from drill
lock assembly 49 out the lower end portion of casing string 13. A
drill bit 55 is coupled to the lower end portion of extension pipe
53 and a reamer 57 is mounted to extension pipe 53 above drill bit
55. Alternately, reamer 57 could be located at the lower end
portion of casing string 13. Logging instruments may also be
incorporated within or coupled to extension pipe 53. A centralizer
59 centralizes extension pipe 53 within casing string 13.
[0024] During drilling, mud pump 37 receives drilling fluid 43 from
mud tank 41 and pumps it through outlet 36 into hose 35, as
illustrated in FIG. 1. The drilling fluid flows through casing
string gripper 27, down casing string 13 and out nozzles (not
shown) at the lower end portion of drill bit 55. Drilling fluid 43
flows back up casing annulus 15 and through annulus outlet flow
line 22 back into mud tank 41. The fluid circulation path is
illustrated by the arrows in FIG. 1.
[0025] FIG. 2 illustrates a schematic diagram of a drill lock
assembly 49, such as a DLA-8SP drill lock assembly, which is
available from Schlumberger Technology Corporation. As noted above,
drill lock assembly 49 may include movable dogs 51 that engage an
annular recess in a sub near the lower end portion of casing string
13 to lock bottom hole assembly 47 (attached to a lower end portion
50 of drill lock assembly 49) in place. Drill lock assembly 49 also
has keys 52 that engage vertical slots for transmitting rotation of
casing string 13 to the bottom hole assembly 47.
[0026] Referring now to FIG. 3, a power retrieving tool assembly
100 according to one or more implementations disclosed herein is
illustrated. The power retrieving tool assembly 100 may also be
referred to herein as a "retrieving tool," a "retrieval apparatus,"
or other like terms. Power retrieving tool assembly 100 may include
a retrieving sub assembly 101 and a power retrieving tool sub
assembly 102. Retrieving sub assembly 101, also referred to as a
latching device, may be configured to latch or couple to the
particular drill lock assembly 49 being used (see FIG. 1), so as to
facilitate retrieval of the bottom hole assembly 47 (FIG. 1).
Retrieval sub assembly 101 may be similar to that as described in,
for example, U.S. patent application publication US2009/0288839,
which provides mechanisms for both latching and detaching from a
drill lock assembly.
[0027] The power retrieving tool assembly 100 may also be coupled
to an electric wireline 103. The electric line may be part of a
commercially available wireline service, such as those provided by
Schlumberger Technology Corporation, among others. The wireline
service may provide pressure control equipment to seal between the
wireline and the top end portion of the casing string. Such
wireline service may also provide a wireline BOP arrangement, as is
well known to those skilled in the art. Wireline 103 may, for
example, be a 0.53-inch OD 7-conductor 16 gauge cable.
[0028] Power retrieving tool assembly 100 includes a pump 108, one
or more pump inlets 107, and one or more pump outlets 118. Power
retrieving tool assembly 100 also includes one or more sealing
devices 116 configured to sealingly engage the inner diameter of
the casing string 13 (FIG. 1). Pump inlets 107 may be located above
sealing devices 116, and pump outlets 118 may be located below
sealing devices 116.
[0029] Sealing devices 116 may be, for example, cup seals. Power
retrieving tool assembly 100 may include upwards facing cup seals
116, sealing against fluid flow downhole past power retrieving tool
assembly 100, as well as downward facing cup seals 116 to seal
against fluid flow uphole.
[0030] As illustrated in FIGS. 5 and 6, power retrieving tool sub
assembly 102 may also include a cable head 104 configured to couple
wireline 103 to the power retrieving tool assembly 100. Wireline
103 may provide one or more of: power to an electric motor (not
shown) to operate pump 108, power and/or communications between an
electric and electronic control module 105, and/or means to apply
additional upward force to the retrieval apparatus 100 (such as by
pulling on or tensioning wireline 103). In at least one
implementation, the exterior of electronic control module 105 may
include external wickers thread for fishing tool engagement.
[0031] Referring now to FIGS. 1 and 3 through 7 in combination,
when a retrieval operation is desired, the power retrieving tool
assembly 100 may be deployed, lowered into the casing string 13
(FIG. 1) to retrieve a tool or a bottom hole assembly 47 (FIG. 1).
The power retrieving tool assembly 100 may be lowered by
gravitational forces or may be pumped through the casing string 13.
It should be noted that the power retrieving tool assembly 100 is
configured for use in highly deviated well profiles as well as in
horizontal well profiles. To pump the power retrieving tool
assembly 100 through the casing string 13, fluid may be pumped into
the casing string 13 through a side inlet or spool part (not shown)
of the surface pressure control equipment. The pressure will act
against an upward facing sealing device 116, with flow passing over
the outside of the retrieval apparatus 100, thereby expanding the
upward facing sealing device 116 into sealing engagement with the
inner diameter of the casing string 13. The seal does not need to
form a tight seal against casing string 13, but should provide
sufficient sealing so as to promote conveyance of the retrieving
assembly through the casing string.
[0032] Retrieving sub assembly 101 latches to drill lock assembly
49 and also releases dogs 51 to allow bottom hole assembly 47 to be
retrieved. Once the power retrieving tool assembly 100, such as
that illustrated in FIG. 3 engages the drill lock assembly 49, such
as that illustrated in FIG. 2, the drill lock assembly 49 may be
released by an upwards pull on the internal components of the drill
lock assembly 49. FIG. 4 illustrates power retrieving tool assembly
100 latched with drill lock assembly 49.
[0033] After the release, or unlocking, of the drill lock assembly
49, the complete bottom hole assembly 47 (FIG. 1) may be moved
uphole and retrieved from the casing string 13 (FIG. 1). The force
needed to initiate movement of the bottom hole assembly 47 may be
created by operating pump 108 via electric power supplied through
the wireline 103. Fluid flows into the pump suction via one or more
inlets 107, downward through the interior (FIG. 6) of the power
retrieving tool assembly 100 via pump discharge outlet 110, flow
paths 111, 117, to one or more outlets 118. Pump 108 thus moves
fluid from above the sealing devices 116 to below sealing devices
116, thus causing a differential pressure across the sealing
devices 116 and forming a low pressure region 122 (FIG. 4). The
pressure below the sealing device 116, i.e., region 120, remains
the bottom hole pressure as defined by the annulus hydrostatic
pressure. The pressure differential provides a hydraulic force
(upwardly acting) to effect retrieval of the bottom hole assembly
47. If desired, additional force may be provided to effect
retrieval via pulling on or tensioning wireline 103. During
retrieval operations, as illustrated in FIG. 7, flow of drilling
fluid within the borehole 11 may be as illustrated by the arrows,
where fluid above the power retrieving tool assembly 100 enters one
or more inlets 107 of the power retrieving tool assembly 100, is
pumped through the internal cavities of the power retrieving tool
assembly 100 via pump 108, exits from one or more outlets 118 of
the power retrieving tool assembly 100, flows downwardly internally
through the bottom hole assembly 47, exits via outlets in drill bit
55, and flows into the wellbore/borehole annulus 15 for
recirculation to the surface.
[0034] The pressure above and below the sealing devices 116 during
the retrieval operation may be measured, and the pressure above the
sealing devices 116 may be controlled. For example, the pressure
may be continuously measured via a pressure measurement system,
such as a dual gauge 112 (FIG. 6), where downhole pressure may be
monitored via port 115 (FIG. 6). Port 115 may be in communication
with the casing fluid at a point below the sealing devices 116, and
the pressure above the sealing devices 116 may be measured through
a port (not shown) in gauge 112. The pressure measurement (and/or
differential pressure measurement) results may then be transmitted
to a surface control unit (not shown) through gauge cable 109 (FIG.
6), control module 105 (FIG. 5), and through one of the conductors
in wireline 103 (FIG. 5). The pressure differential across seals
116 may be continuously monitored and controlled by adjusting the
speed of pump 108 or by operating pump 108 intermittently.
[0035] The retrieval speed may thus be controlled by the
differential pressure (the hydraulic force applied) across seals
116, as well as by application of additional force to the wireline
103. The retrieval speed may be further adjusted by varying the
differential pressure, the force applied to the wireline 103, or
both.
[0036] The retrieval operations as described above may be performed
with fluid static in the borehole 11 or with fluid circulating
through the borehole 11. For example, with fluid static in the
borehole 11, no fluid is being introduced via flow line 35 (FIG.
1). The pumping action reduces the level of fluid above the
retrieval apparatus 100 and reduces the pump inlet pressure, as
well as decreases the weight of fluid bearing down on the retrieval
apparatus 100, progressively moving the retrieval apparatus 100
upward through the casing string 13. The pump speed (and thus the
differential pressure) may be adjusted throughout the retrieval
operation to maintain the fluid relatively static within the
annulus 15.
[0037] During the initial pumping (even during static operations),
to create a reduced fluid level inside the casing string 13, fluid
may be circulated and returned to the surface through the annulus
15 between the casing string 13 and the borehole 11. The effect on
the bottom hole pressure will be similar to that of any other
normal circulation operation with the annulus 15 fully open at the
surface.
[0038] Adding fluid to the casing string 13 above the retrieval
apparatus 100 may facilitate the complete retrieval of the bottom
hole assembly 47. For example, lost level due to initial pumping or
to other inefficiencies during the retrieval operation may result
in a fluid level insufficient to attach the retrieval apparatus 100
to a grapple (not shown). As such, fluid added to the casing string
13 may provide for continued pumping and hydraulic force to lift
the retrieval apparatus 100 to a point where it may be engaged with
a grapple and held in place along with the bottom hole assembly
47.
[0039] Once the bottom hole assembly 47 approaches the fluid level
in the casing string 13, additional fluid may be added to the
casing string 13 to reduce the differential pressure (hydraulic
lift). The lost force may be replaced by increasing or adding
tension from the wireline 103. There is more force available from
the wireline 103 near the surface, as the reduction of available
force due to the weight of the wireline 103 in the borehole 11 is
small near the surface. Further, the effect of pulling slowly for a
short section near surface has a small overall effect on the time
needed for the retrieval operation.
[0040] Once at the surface, the well pressure may be monitored.
When static, the surface pressure control equipment may be
disconnected from the upper end portion of the casing string 13 and
the wireline tools, and the bottom hole assembly 47 may be
recovered.
[0041] As noted above, retrieval operations disclosed herein may be
performed while circulating fluids through the borehole 11. Fluid
may be continually added to the casing string 13 at the surface.
The pump speed may be operated to generate a differential pressure
across the retrieval apparatus 100 to effect retrieval, compensate
for the upwards movement of the bottom hole assembly 47, as well as
to provide sufficient fluid flow rate to maintain fluid circulation
from the casing string 13, to the casing string annulus 15, and
back to the surface.
[0042] As described above, one or more implementations disclosed
herein relate to a power retrieving tool assembly. The power
retrieving tool assembly adds a powered element to wireline
retrieval methods while allowing an operator to keep the bottom
hole pressure constant or nearly constant. The tool, e.g., a bottom
hole assembly, to be retrieved is carried out of the borehole
partly by tension from the wireline and partly by lift across a
sealing element with the lift created by a reduced height of the
fluid column inside the tubular, e.g., casing string, from where it
is retrieved.
[0043] One or more implementations disclosed herein also greatly
increase the pulling capacity of a retrieving tool by
synergistically combining hydraulic lift force with cable tension.
The hydraulic lift force is created by pumping fluid from above the
retrieving tool to below the retrieving tool. In an alternative
configuration the concepts described above may be further expanded
by adding a slip-arrangement that can anchor the power retrieving
tool to the casing in the event of unforeseen problems.
[0044] One or more implementations disclosed herein, whether using
pump-only or pump-and-pull operations, may provide an improvement
in the time to retrieve a tool from downhole. For example, a 10,000
foot retrieval using wireline retrieval may take twenty-four hours
to complete. In contrast, one or more implementations disclosed
herein may perform the same 10,000 foot retrieval in less than
about 8 hours.
[0045] Additionally, it is feasible to circulate the wellbore or
borehole at the same time as retrieving a tool by increasing the
pump rate through the retrieving tool beyond the rate to move the
tool, while simultaneously adding fluid to the tubular string at
the surface. This method allows circulating while retrieving
without having to work against the pressure drop created by fluid
flowing through the retrieving tool and the tool to be
retrieved.
[0046] Further, the method may maintain atmospheric pressure below
the wireline stuffing box at the surface. The bottom hole pressure
is kept constant to the same degree as it would be in any other
slow circulation of the well. While described above in relation to
casing-while-drilling operations, one or more of the retrieval
tools disclosed herein may be equally suited to other drilling and
production operations, such as retrieving a tool or bottom hole
assembly through a casing string in a conventional drilling or
completion operation, as well as retrieval through a tubular string
in a conventional well service operation, among others.
Furthermore, one or more of the retrieval tools disclosed herein
may be equally suited for non-drilling applications in which a tool
or other object is desired to be removed from a tubular.
[0047] One or more implementations disclosed herein may also
provide for faster retrieval as compared to drill pipe retrieval.
Rigging may be similar to that used for conventional wireline
operation, with running in and retrieval speeds higher than for
drill pipe. Such implementations may also allow for continuous
circulation during retrieval, continuously having pressure control
equipment engaged at the surface, and being able to circulate while
retrieving tools. It may also be possible to reciprocate the casing
while performing the retrieving operation.
[0048] One or more implementations disclosed herein may also be
useful over wireline-only retrieval. While using wireline, such
implementations provide a much greater upward force at depth, such
as when the bottom hole assembly is exposed to open hole (e.g.,
when not within the casing). Further, such implementations may
provide zero pressure on the stuffing box during retrieval, thus
allowing for continuous circulation during the retrieval process,
and less wear on the stuffing box. Higher retrieval speeds, due to
the greater force available, are also possible as compared to
wireline-only retrieval.
[0049] One or more implementations are described above with regard
to retrieval of bottom hole assemblies or other downhole
tools/objects. Such implementations may also be useful for other
wireline conveyed operations, for example, as an alternative to
tractors or as a complimentary technique to tractors.
[0050] As used herein, the terms "inner" and "outer"; "up" and
"down"; "upper" and "lower"; "upward" and "downward"; "above" and
"below"; "inward" and "outward"; and other like refer to relative
positions to one another and are not intended to denote a
particular direction or spatial orientation. The terms "couple,"
"coupled," "connect," "connection," "connected," "in connection
with," and "connecting" refer to "in direct connection with" or "in
connection with via one or more intermediate elements or
members."
[0051] Although only a few example implementations have been
described in detail above, those skilled in the art will readily
appreciate that many modifications are possible in the example
implementations without materially departing from "Power Retrieving
Tool." Accordingly, all such modifications are intended to be
included within the scope of this disclosure. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and not only
structural equivalents, but also equivalent structures. Thus,
although a nail and a screw may not be structural equivalents in
that a nail employs a cylindrical surface to secure wooden parts
together, whereas a screw employs a helical surface, in the
environment of fastening wooden parts, a nail and a screw may be
equivalent structures.
[0052] Certain implementations and features have been described
using a set of numerical upper limits and a set of numerical lower
limits. It should be appreciated that ranges including the
combination of any two values, e.g., the combination of any lower
value with any upper value, the combination of any two lower
values, and/or the combination of any two upper values are
contemplated unless otherwise indicated. Certain lower limits,
upper limits and ranges appear in one or more claims below. All
numerical values are "about" or "approximately" the indicated
value, and take into account experimental error and variations that
would be expected by a person having ordinary skill in the art.
[0053] Various terms have been defined above. To the extent a term
used in a claim is not defined above, it should be given the
broadest definition persons in the pertinent art have given that
term as reflected in at least one printed publication or issued
patent. Furthermore, all patents, test procedures, and other
documents cited in this application are fully incorporated by
reference to the extent such disclosure is not inconsistent with
this application and for all jurisdictions in which such
incorporation is permitted.
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