U.S. patent application number 14/408061 was filed with the patent office on 2015-05-28 for method and apparatus for tool retrieval.
This patent application is currently assigned to Schlumberger Technology Corporation. The applicant listed for this patent is Schlumberger Technology Corporation. Invention is credited to Larry Victor Cooper, Robert M. Ramsey.
Application Number | 20150144354 14/408061 |
Document ID | / |
Family ID | 49882465 |
Filed Date | 2015-05-28 |
United States Patent
Application |
20150144354 |
Kind Code |
A1 |
Cooper; Larry Victor ; et
al. |
May 28, 2015 |
Method And Apparatus For Tool Retrieval
Abstract
The present disclosure is directed towards, in general,
retrieval tools operable for conveyance within a wellbore extending
below a wellsite surface, and methods of using such retrieval
tools. One such retrieval tool comprises an annular member operable
to receive a conveyance terminating at a downhole tool lodged
within the wellbore. The annular member may subsequently receive
and engage a portion of the downhole tool. The retrieval tool also
comprises a flapper selectively operable to sever the conveyance if
the downhole tool cannot be dislodged from the wellbore.
Inventors: |
Cooper; Larry Victor; (Lake
Charles, LA) ; Ramsey; Robert M.; (Missouri City,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schlumberger Technology Corporation |
Sugar Land |
TX |
US |
|
|
Assignee: |
Schlumberger Technology
Corporation
Sugar Land
TX
|
Family ID: |
49882465 |
Appl. No.: |
14/408061 |
Filed: |
July 2, 2013 |
PCT Filed: |
July 2, 2013 |
PCT NO: |
PCT/US13/49063 |
371 Date: |
December 15, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61667328 |
Jul 2, 2012 |
|
|
|
Current U.S.
Class: |
166/377 ;
166/54.5 |
Current CPC
Class: |
E21B 29/04 20130101;
E21B 23/14 20130101; E21B 31/12 20130101; E21B 31/00 20130101 |
Class at
Publication: |
166/377 ;
166/54.5 |
International
Class: |
E21B 23/14 20060101
E21B023/14; E21B 29/04 20060101 E21B029/04; E21B 31/00 20060101
E21B031/00 |
Claims
1. A method, comprising: conveying a retrieval tool along a
conveyance within a wellbore extending into a subterranean
formation; utilizing the retrieval tool in an attempt to engage and
retrieve a downhole tool in the wellbore; and severing the
conveyance with the retrieval tool downhole upon failure of the
attempt.
2. The method of claim 1 wherein conveying the retrieval tool along
the conveyance comprises conveying the retrieval tool on a pipe
string to which the retrieval tool is coupled.
3. The method of claim 2 wherein conveying the retrieval tool along
the conveyance comprises sliding the retrieval tool and the pipe
string over the conveyance.
4. The method of claim 1 wherein the conveyance comprises a cable
extending between the downhole tool and a well-site surface from
which the wellbore extends.
5. The method of claim 4 wherein the cable comprises at least one
of a wireline and a slickline.
6. The method of claim 1 wherein the conveyance comprises coiled
tubing extending between the downhole tool and a well-site surface
from which the wellbore extends.
7. The method of claim 1 wherein severing the conveyance with the
retrieval tool comprises selectively operating a flapper assembly
of the retrieval tool.
8. The method of claim 7 wherein conveying the retrieval tool along
the conveyance within the wellbore comprises passing the conveyance
through the flapper assembly.
9. The method of claim 8 wherein severing the conveyance with the
retrieval tool comprises closing the flapper on the conveyance with
sufficient force to sever the conveyance.
10. The method of claim 9 wherein closing the flapper comprises
pumping fluid down the wellbore from a well-site surface from which
the wellbore extends.
11. The method of claim 10 wherein the flapper is mechanically
biased towards an open position, and wherein pumping fluid down the
wellbore from the well-site surface comprises pumping the fluid at
a rate sufficient for the fluid to overcome the mechanical bias and
urge the flapper away from the open position.
12. An apparatus, comprising: a retrieval tool operable for
conveyance within a wellbore extending below a wellsite surface,
wherein the retrieval tool comprises: an annular member operable to
receive a conveyance terminating at a downhole tool lodged within
the wellbore, and then receive and engage a portion of the downhole
tool; and a flapper operable to sever the conveyance.
13. The apparatus of claim 12 wherein the flapper is biased towards
an open position permitting passage of the conveyance.
14. The apparatus of claim 12 wherein the wellbore comprises a
substantially non-vertical section.
15. The apparatus of claim 12 wherein the conveyance comprises a
cable extending between the wellsite surface and the downhole
tool.
16. The apparatus of claim 12 wherein the conveyance comprises
coiled tubing extending between the wellsite surface and the
downhole tool.
17. An apparatus, comprising: a fishing string operable for
conveyance within a wellbore extending below a wellsite surface,
wherein the fishing string comprises: a mule shoe operable to
receive a conveyance terminating at a downhole tool lodged within
the wellbore, and then to receive a portion of the downhole tool;
an overshot operable to receive the conveyance, and then to receive
and engage a portion of the downhole tool; and a flapper assembly
operable to sever the conveyance.
18. The apparatus of claim 17 wherein the flapper assembly is
biased towards a position permitting passage of the conveyance
therein.
19. The apparatus of claim 17 wherein the conveyance comprises a
cable extending between the wellsite surface and the downhole
tool.
20. The apparatus of claim 17 wherein the conveyance comprises
coiled tubing extending between the wellsite surface and the
downhole tool.
Description
BACKGROUND OF THE DISCLOSURE
[0001] In a variety of well-related operations, downhole tools are
utilized to carry out desired tasks at downhole locations. For
example, different types of downhole tools may be utilized to drill
wellbores, deploy tubing and other equipment downhole, perform
testing operations, and conduct servicing operations, among other
possibilities. During these operations, a downhole tool may become
lodged in the wellbore or disconnected from its conveyance. The
lodged tool may be referred to as a fish, and a fishing operation
may be performed in an attempt to retrieve the fish. For example, a
fishing tool may be deployed downhole from a surface rig or
platform. The fishing tool comprises a latching or attachment end
intended to engage the fish to be retrieved. If the fish cannot be
dislodged from the wellbore, the fishing tool is removed from the
well. Another downhole tool may then be deployed to separate the
fish from its conveyance, such that the conveyance may be retrieved
to surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] The present disclosure is best understood from the following
detailed description when read with the accompanying figures. It is
emphasized that, in accordance with the standard practice in the
industry, various features are not drawn to scale. In fact, the
dimensions of the various features may be arbitrarily increased or
reduced for clarity of discussion.
[0003] FIG. 1 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0004] FIG. 2 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0005] FIG. 3 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0006] FIG. 4 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0007] FIG. 5 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0008] FIG. 6 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0009] FIG. 7 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0010] FIG. 8 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0011] FIG. 9 is a schematic view of at least a portion of
apparatus according to one or more aspects of the present
disclosure.
[0012] FIG. 10 is a flow-chart diagram of at least a portion of a
method according to one or more aspects of the present
disclosure.
DETAILED DESCRIPTION
[0013] It is to be understood that the following disclosure
provides many different embodiments, or examples, for implementing
different features of various embodiments. Specific examples of
components and arrangements are described below to simplify the
present disclosure. These are, of course, merely examples and are
not intended to be limiting. In addition, the present disclosure
may repeat reference numerals and/or letters in the various
examples. This repetition is for the purpose of simplicity and
clarity and does not in itself dictate a relationship between the
various embodiments and/or configurations discussed. Moreover, the
formation of a first feature over or on a second feature in the
description that follows may include embodiments in which the first
and second features are formed in direct contact, and may also
include embodiments in which additional features may be formed
interposing the first and second features, such that the first and
second features may not be in direct contact.
[0014] An overshot is a type and/or portion of a fishing or other
retrieval tool and/or tool string that may utilized in fishing
operations to engage a surface and/or other portion of a tube or
downhole tool that has become lodged downhole. Fishing may comprise
attempting to grip and/or otherwise engage the fish via a grapple
and/or other slip mechanism of the overshot, thus allowing the
application of tensile and/or jarring forces intended to dislodge
the fish. The fish may comprise a "fishing neck" and/or other
member or surface intended to aid engagement between the fish and
the fishing tool. If the fish cannot be removed, a release
mechanism of the overshot may allow the overshot to be disengaged
from the fish and retrieved to surface.
[0015] Fishing tools may generally fall into four classes:
diagnostic, inside grappling, outside grappling, and force
intensifiers or jars. Diagnostic devices may range from a simple
impression block made in a soft metal (e.g., lead) that may be
dropped rapidly onto the top of the fish so that, upon inspection
at the surface, the surface operator (or "fisherman") may be able
to custom design a retrieval tool to facilitate attachment to and
removal of the fish. Other diagnostic tools may include electronic
instruments and/or downhole sonic or visual-bandwidth cameras.
Inside grappling devices (which may be referred to as "spears") may
have a tapered and threaded profile, enabling the fisherman to
first guide the tool onto the top of the fish, and then thread the
fishing tool into the top of the fish so that recovery may be
attempted. Outside grappling devices (referred to herein as
"overshots") may comprise an annular member that "swallows" the
fish and does not release it as it is pulled out of the wellbore.
One or more aspects of the present disclosure may be applicable or
readily adaptable to any of the apparatus described above, as well
as operations involving such apparatus.
[0016] The present disclosure introduces an apparatus comprising: a
retrieval tool operable for conveyance within a wellbore extending
below a wellsite surface, wherein the retrieval tool comprises: an
annular member operable to receive a conveyance terminating at a
downhole tool lodged within the wellbore, and then receive and
engage a portion of the downhole tool; and a flapper operable to
sever the conveyance. The flapper may be spring-loaded or otherwise
biased towards an open position permitting passage of the
conveyance. The wellbore may comprise a substantially horizontal
and/or otherwise substantially non-vertical section. The conveyance
may comprise a cable and/or coiled tubing extending between the
wellsite surface and the downhole tool. The cable may comprise a
wireline and/or a slickline.
[0017] The present disclosure also introduces an apparatus
comprising: a fishing string operable for conveyance within a
wellbore extending below a wellsite surface, wherein the fishing
string comprises: a mule shoe operable to receive a conveyance
terminating at a downhole tool lodged within the wellbore, and then
to receive a portion of the downhole tool; an overshot operable to
receive the conveyance, and then to receive and engage a portion of
the downhole tool; and a flapper assembly operable to sever the
conveyance. The flapper assembly may be biased towards a position
permitting passage of the conveyance therein. The conveyance may
comprise a cable and/or coiled tubing extending between the
wellsite surface and the downhole tool. The cable may comprise a
wireline and/or a slickline.
[0018] The present disclosure also introduces a method comprising:
conveying a retrieval tool along a conveyance within a wellbore
extending into a subterranean formation; utilizing the retrieval
tool in an attempt to engage and retrieve a downhole tool in the
wellbore; and severing the conveyance with the retrieval tool
downhole upon failure of the attempt. Conveying the retrieval tool
along the conveyance may comprise conveying the retrieval tool on a
pipe string to which the retrieval tool is coupled. Conveying the
retrieval tool along the conveyance may comprise sliding the
retrieval tool and the pipe string over the conveyance. The
conveyance may comprise a cable extending between the downhole tool
and a well-site surface from which the wellbore extends. The cable
may comprise a wireline and/or a slickline. The conveyance may
comprise coiled tubing extending between the downhole tool and a
well-site surface from which the wellbore extends. Severing the
conveyance with the retrieval tool may comprise selectively
operating a flapper assembly of the retrieval tool. Conveying the
retrieval tool along the conveyance within the wellbore may
comprise passing the conveyance through the flapper assembly.
Severing the conveyance with the retrieval tool may comprise
closing the flapper on the conveyance with sufficient force to
sever the conveyance. Closing the flapper may comprise pumping
fluid down the wellbore from a well-site surface from which the
wellbore extends. The flapper may be mechanically biased towards an
open position, and pumping fluid down the wellbore from the
well-site surface may comprise pumping the fluid at a rate
sufficient for the fluid to overcome the mechanical bias and urge
the flapper away from the open position.
[0019] An example fishing string 100 comprising an overshot 110
according to one or more aspects of the present disclosure is
depicted in FIG. 1. The fishing string 100 is suspended in the
wellbore 105 via a wireline, slickline, pipe, and/or other
conveyance 120. The fishing string 100 may also comprise an
accelerator 130, a section of pipe or pipe string 140, a jar 150,
and/or a bumper sub 160. The order of the components of the fishing
string 100 may vary from that shown in FIG. 1, and the fishing
string 100 may comprise fewer components than those depicted in
FIG. 1, as well as additional components not otherwise described
herein.
[0020] The accelerator 130 and/or the jar 150 may store energy that
is suddenly released upon activation. While there are two primary
types of accelerators and jars (hydraulic and mechanical), their
operation is similar. For example, energy is stored in the
conveyance 120 and/or other components of the fishing string 100,
and this energy is suddenly released upon activation of the
accelerator 130 and/or the jar 150. The principle is similar to
that of a carpenter using a hammer. Kinetic energy stored in the
hammer as it is swung is suddenly released to the nail and board
when the hammer strikes the nail. When utilizing the accelerator
130 and/or the jar 150, the fisherman may pull up on the conveyance
120, but the fish 170 does not move. Since the top of the
conveyance 120 (at surface) is moving upward, the conveyance 120 is
stretching and storing energy. Upon activation, a dynamic portion
of the jar 150 rapidly translates in an uphole direction until
slamming into a shoulder or stop of a static portion the jar 150,
thus imparting an impact force to the static portion of the jar
150, which is mechanically transferred to the fish 170 via the
overshot 110 and/or other components of the fishing string that may
be positioned between the jar 150 and the fish 170. The accelerator
130 may similarly impart such an impact. The impact force applied
to the fish 170 in this manner may aid in the release of the fish
170 engaged by the overshot 110.
[0021] The section of pipe or pipe string 140 may be included in
the fishing string 100 to increase the mass suddenly propelled in
an uphole direction upon activation of the accelerator 130 and/or
the jar 150, and/or to provide sufficient weight acting downward on
the accelerator 130 and/or the jar 150 such that they may be reset
in preparation for a subsequent activation. The bumper sub 160 may
be included as a mechanical buffer or the like, such as may lessen
the likelihood of the fish 170 being damaged by the impact force
imparted by activation of the accelerator 130 and/or the jar
150.
[0022] An overshot, fishing tool, and/or other retrieval tool
(collectively referred to hereafter as simply "retrieval tool")
according to one or more aspects of the present disclosure may be
fed over the conveyance and deployed downhole to engage the fish.
Such operation may utilize a "cut and thread" method, in which the
conveyance is gripped and cut at surface. The cut end is threaded
through one or more joints or stands of pipe and/or other means of
conveying the retrieval tool (hereafter collectively referred to as
"pipe" for the sake of simplicity), which are then lowered and
temporarily suspended in the wellbore. The conveyance is then
threaded through another one or more joints or stands of pipe,
which are then coupled to the pipe suspended in the wellbore. This
process is repeated until the retrieval tool at the lower end of
the pipe suspended in the wellbore can no longer be translated
further into the borehole, either because the retrieval tool has
reached the fish, or because the retrieval tool itself has become
lodged in the wellbore at a depth shallower than the fish.
[0023] Thus, in certain situations, the retrieval tool may not be
able to engage or subsequently dislodge the fish. Accordingly,
retrieval tools within the scope of the present disclosure also
comprise a flapper assembly that may be utilized to cut the
conveyance as close to the fish as possible to allow retrieval of a
substantial portion of the conveyance. Thus, retrieval tools
according to one or more aspects of the present disclosure may
enable retrieval of the fish by engagement of the fish with the
retrieval tool and, if the fish cannot be retrieved, retrieval of
at least a portion of the conveyance by cutting the conveyance with
the flapper assembly. Retrieval tools within the scope of the
present disclosure may be utilized in various downhole operations,
including within wellbores that comprise one or more substantially
horizontal or otherwise substantially non-vertical portions, in
which conveying the retrieval tool to the fish may be difficult
using traditional, gravity-fed techniques.
[0024] FIG. 2 is a schematic view of at least a portion of an
implementation of the fishing string 100 shown in FIG. 1 according
to one or more aspects of the present disclosure. The illustrated
portion includes a retrieval tool 200, a mule shoe 202, and an
overshot 204 coupled between the retrieval tool 200 and the mule
shoe 202. The retrieval tool 200, the mule shoe 202, and the
overshot 204 may be coupled as shown in FIG. 2 via
industry-standard box-pin connections, among other means within the
scope of the present disclosure. A wireline, slickline, coiled
tubing, and/or other conveyance 206, depicted as extending through
the retrieval tool 200, the overshot 204, and the mule shoe 202,
may be connected to a fish (not shown).
[0025] FIG. 3 is an enlarged view of the retrieval tool 200 shown
in FIG. 2. The retrieval tool 200 may comprise a housing 210
extending between an upper sub 220 and a lower sub 230. The upper
and lower subs 220 and 230 may be coupled within the fishing string
via industry-standard box-pin connections, among other means within
the scope of the present disclosure. A sleeve 240, a flapper
assembly 250, and a biaser 260 may be disposed within the housing
230. The flapper assembly 250 is depicted in an open position in
FIG. 2 and in a closed position in FIG. 3.
[0026] FIG. 4 is an enlarged view of a portion of the retrieval
tool 200 shown in FIG. 2. The flapper assembly 250 is depicted in
FIG. 4 as being in an open position, such that the conveyance 206
extending through the retrieval tool 200 may also extend through
the flapper assembly 250.
[0027] Operations utilizing the retrieval tool 200 will now be
described with reference to FIGS. 2-4, collectively. During fishing
operations, the cut and thread method described above may be
utilized to convey the retrieval tool 200 towards the fish (not
shown). During the cut and thread method, or any other method
utilized to convey the retrieval tool 200 within the wellbore, the
conveyance 206 will pass through the mule shoe 202, the overshot
204, and the retrieval tool 200, including through the flapper
assembly 250. The biaser 260 may enable pipe movement in the upward
direction, such as during unsetting and setting the slips, without
inadvertently affecting the flapper assembly 250. After the
retrieval tool 200 is fed downhole over the conveyance 206 to the
fish, the surface operator may attempt to engage the fish with the
overshot 204 and pull the fish out of the wellbore. If it is not
possible to engage the fish with the overshot 204, the surface
operator may apply pressure or overpull such that the flapper
assembly 250 may sever the conveyance 206. The option of severing
the conveyance 206 may be a secondary to retrieving the fish, but
it may nonetheless be a better option relative to leaving the
entire conveyance 206 within the wellbore. Moreover, by utilizing a
retrieval tool according to one or more aspects of the present
disclosure, the conveyance 206 may be severed from the fish as part
of a single retrieval operation, instead of pulling the retrieval
tool out of the wellbore and then inserting a separate cutting tool
into the wellbore to sever the conveyance 206.
[0028] The biaser 260 depicted in the figures comprises a helical
compression spring coupled and/or extending between the flapper
assembly 250 and the lower sub 230. However, other means for
permitting axial translation of the retrieval tool 200 relative to
the fish without inadvertently severing the conveyance 206 are also
within the scope of the present disclosure.
[0029] As depicted in FIG. 4, the flapper assembly 250 may maintain
an open position as the retrieval tool 200 travels down the
conveyance 206 toward the fish. In some scenarios, as described
above, if the fish cannot be retrieved, the conveyance 206 may be
severed before the retrieval tool 200 is returned to surface. For
example, fluid may be pumped from surface down through the
retrieval tool 200. The fluid may comprise drilling fluid ("mud"),
hydraulic fluid, fracturing fluid, and/or other fluids. The flow of
such fluid may act on the flapper assembly 250 to move the flapper
255 away from the inside wall of the sleeve 240, thus partially
closing the flapper assembly 250 and partially engaging the
conveyance 206 between the flapper 255 and a base 257 of the
flapper assembly 250. This partially closed position of the flapper
255 is depicted in FIG. 5. The retrieval tool 200 is then moved in
an uphole direction and, because the conveyance 206 remains
attached to the fish below the retrieval tool 200, the flapper 255
will further close on the conveyance 206 until, with sufficient
uphole movement of the retrieval tool 200, the flapper assembly 250
will sever the conveyance 206. The closed flapper assembly 250,
after having severed the conveyance 206, is depicted in FIG. 6.
[0030] FIG. 7 is a schematic view of an implementation of the
flapper assembly 250 described above, and depicted as being
oriented in a partially open configuration. FIG. 8 is a sectional
view of the flapper assembly 250 shown in FIG. 7, but in a closed
configuration. FIG. 9 is a top view of the flapper assembly 250
shown in FIGS. 7 and 8, where the flapper assembly 250 is depicted
in an open configuration. Referring to FIGS. 7-9 collectively, the
flapper 255 may be rotationally coupled to the base 257 by a hinge
310. The hinge 310 may comprise a flange 320 coupled to and
extending from the base 257, and a member 330 extending through the
flange 320 and the flapper 255. The member 330 may be a
substantially cylindrical pin, such as may be press-fit within
corresponding holes 340 in the flange 320 and extending through a
corresponding hole in the flapper 255. However, other methods of
rotationally coupling the flapper 255 to the base 257 are also
within the scope of the present disclosure.
[0031] The flapper 255 may be biased towards an open position. For
example, the flapper assembly 250 may comprise one or more torsion
springs and/or other means (not shown) intended to bias the flapper
255 away from the closed position shown in FIG. 8. However, such
biasing means may not be included, such that the flapper 255 may be
urged away from the closed position merely by the existence of the
conveyance 206 extending through the opening or other passage 350
of the base 257. By including the passage 350 in the base 257, the
base 257 may be considered an annular member to which the flapper
255 is rotationally coupled.
[0032] The flapper 255 may comprise a closure portion 360 and a
flange 370 extending centrally from the closure portion 360. The
flange 370 may have a top edge or surface 375 sized to prevent the
flapper 255 from rotating to a substantially vertical orientation
parallel with the longitudinal axis of the retrieval tool 200.
Thus, at its fully open position, as shown in FIG. 9, the closure
portion 360 and/or the flange 370 may form one or more pockets 380
and/or other areas intended to react to the flow of fluid and
thereby urge the flapper 255 towards the closed position shown in
FIG. 8.
[0033] The flapper assembly 250 may be coupled within and/or
otherwise to the sleeve 240 shown in FIGS. 1-6 and 9. The sleeve
240 and flapper assembly 250 may be able to axially float relative
to the housing 210 depending on whether the flapper 255 is engaged
with the conveyance 206 during the above-described severing
operation. The sleeve 240 may also comprise one or more openings
390 permitting the passage of fluid flow into the annulus defined
between the fishing string and the wellbore.
[0034] The various components of the retrieval tool 200, including
those of the flapper assembly 250, may comprise one or more steel
materials commonly utilized in the downhole environment. However,
other substantially rigid materials are also within the scope of
the present disclosure.
[0035] FIG. 10 is a flow-chart diagram of at least a portion of an
example method 700 according to one or more aspects of the present
disclosure. The method 700 may be performed utilizing the apparatus
shown in FIGS. 1-9 and/or otherwise within the scope of the present
disclosure.
[0036] The method 700 comprises the attempted retrieval (710) of
the fish utilizing the retrieval tool 200 described above and/or
other retrieval tools according to one or more aspects of the
present disclosure. The method 700 also comprises a subsequent
determination (720) of whether the fish has been successfully
dislodged from the wellbore. If it is determined that the fish has
been successfully dislodged, then the retrieval tool, the dislodged
fish, and the conveyance coupled to the fish may be returned (730)
to surface.
[0037] However, if it is determined that the fish has not been
successfully dislodged from the wellbore, then the conveyance
coupled to the fish may be severed (740) from the fish, such as by
actuating the flapper assembly 250 described above. The retrieval
tool and the severed conveyance may then be returned (750) to
surface, abandoning the fish downhole.
[0038] The foregoing outlines features of several embodiments so
that those skilled in the art may better understand the aspects of
the present disclosure. Those skilled in the art should appreciate
that they may readily use the present disclosure as a basis for
designing or modifying other processes and structures for carrying
out the same purposes and/or achieving the same advantages of the
embodiments introduced herein. Those skilled in the art should also
realize that such equivalent constructions do not depart from the
spirit and scope of the present disclosure, and that they may make
various changes, substitutions and alterations herein without
departing from the spirit and scope of the present disclosure.
[0039] The Abstract at the end of this disclosure is provided to
comply with 37 C.F.R. .sctn.1.72(b) to allow the reader to quickly
ascertain the nature of the technical disclosure. It is submitted
with the understanding that it will not be used to interpret or
limit the scope or meaning of the claims.
* * * * *