U.S. patent application number 14/196887 was filed with the patent office on 2015-09-10 for anchor-based conveyance in a well.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. The applicant listed for this patent is SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to MOHAMMED BADRI, REZA TAHERIAN.
Application Number | 20150252641 14/196887 |
Document ID | / |
Family ID | 54016869 |
Filed Date | 2015-09-10 |
United States Patent
Application |
20150252641 |
Kind Code |
A1 |
BADRI; MOHAMMED ; et
al. |
September 10, 2015 |
ANCHOR-BASED CONVEYANCE IN A WELL
Abstract
An anchor is placed in a wellbore to convey loads into a
wellbore. The anchor is placed at some desired location in a
wellbore and installed at that location using, for example, arms
that penetrate into the formation surrounding the anchor. A line
extends from the surface, wraps around a pulley in the anchor and
attaches to the downhole end of the load. Tension is applied at the
surface to the line to pull the load to a desired location in the
wellbore. Optionally, the same or a second line can be attached to
the uphole end of the load to reposition or retrieve the load.
Alternatively, a powered anchor has a line drive device and a
spool. A portion of a line extends from the anchor to the load. The
line is spooled onto the spool by the line drive device, thereby
pulling the load into the wellbore.
Inventors: |
BADRI; MOHAMMED; (AL-KHOBAR,
SA) ; TAHERIAN; REZA; (AL-KHOBAR, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHLUMBERGER TECHNOLOGY CORPORATION |
SUGAR LAND |
TX |
US |
|
|
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
SUGARLAND
TX
|
Family ID: |
54016869 |
Appl. No.: |
14/196887 |
Filed: |
March 4, 2014 |
Current U.S.
Class: |
166/385 ;
166/206 |
Current CPC
Class: |
E21B 23/14 20130101 |
International
Class: |
E21B 23/14 20060101
E21B023/14 |
Claims
1. A method, comprising: disposing an anchor in a first desired
location in a wellbore; installing the anchor into a formation
surrounding the anchor; and using a line moveably constrained by
the anchor to pull a load to a second desired location in the
wellbore.
2. The method of claim 1, further comprising using the line to
reposition or retrieve the load.
3. The method of claim 1, wherein the disposing an anchor comprises
using a self-propelled anchor.
4. The method of claim 1, wherein the installing the anchor
comprises causing anchor arms to penetratingly engage the
formation.
5. The method of claim 1, wherein the installing the anchor
comprises releasing anchor arms from a retracted position and
causing the anchor arms to penetratingly engage the formation.
6. The method of claim 1, wherein the using a line moveably
constrained by the anchor to pull a load comprises using a drive
mechanism to produce a tensile force in the line.
7. The method of claim 1, wherein the line and the load form a
closed loop.
8. The method of claim 1, further comprising using a leader in
conjunction with the line.
9. An apparatus, comprising: an anchor having one or more anchor
arms, wherein the anchor is disposed and installed in a wellbore; a
first line moveably constrained by the anchor; and a drive
mechanism capable of producing a tensile force in the first
line.
10. The apparatus of claim 9, further comprising a locomotion
device.
11. The apparatus of claim 9, wherein the first line is moveably
constrained by an anchor pulley.
12. The apparatus of claim 9, wherein the first line is further
moveably constrained by one or more wellbore pulleys disposed in
various locations in the wellbore.
13. The apparatus of claim 9, further comprising a biasing force
mechanism capable of applying a bias force to the one or more
anchor arms.
14. The apparatus of claim 13, wherein the one or more anchor arms
have a retracted configuration and an extended configuration, and
the biasing force mechanism can release the one or more anchor arms
from the retracted configuration and drive them to the extended
configuration and/or release the one or more anchor arms from the
extended configuration and drive them to the retracted
configuration.
15. The apparatus of claim 9, further comprising a leader in lieu
of the first line.
16. The apparatus of claim 9, wherein the first line comprises
electrical and/or logic wires.
17. The apparatus of claim 9, further comprising a second line
attached to a load disposed in the wellbore.
18. The apparatus of claim 9, wherein the drive mechanism is
disposed on the anchor, elsewhere in the wellbore, or at the earth
surface.
19. An apparatus, comprising: an anchor comprising one or more
anchor arms, a line drive device, and a spool, wherein the anchor
is disposed and installed in a wellbore; and a line that extends
from the anchor into the wellbore and is capable of being spooled
onto the spool by the line drive device; wherein the line drive
device is capable of producing a tensile force in at least the
portion of the line that extends into the wellbore.
20. The apparatus of claim 19, wherein the portion of the line that
extends into the wellbore is attached to or near a downhole end of
a load.
21. The apparatus of claim 20, wherein the line extends through or
around the load, is attached to or near an uphole end of the load,
and further extends to a drive mechanism capable of producing a
tensile force in the line.
22. The apparatus of claim 19, wherein the line comprises
electrical and/or logic wires.
Description
BACKGROUND
[0001] In the petroleum industry, before a downhole measurement or
operation can be performed in a well, a logging tool is deployed to
a depth of interest. Current modes of deployment generally include
wireline, drill string, coil tubing (CT), slick line, and downhole
tractors. Drill string is generally considered the strongest mode
and is capable of exerting a force sufficient to deploy relatively
large loads into vertical, horizontal, and deviated wells. It can
be used to deploy a logging tool even into horizontal, vertical or
deviated wells having dog legs. In contrast, a wireline deployment
does not provide its own force, but instead relies on gravity to
deploy. It therefore works well in vertical wells and in deviated
wells with small deviations from vertical, but cannot deploy in
horizontal wells or vertical wells with severe dog legs.
Traditionally, wireline conveyance has relied on having a rig in
place, though recently there is a trend to perform some of the
operations in a rig-less environment. Like wireline, a slick line
is not driven and as a result works reliably in vertical (or
slightly deviated) wells.
[0002] Coil tubing is a driven deployment mode. It can work in
horizontal, vertical, and deviated wells, but it is not as strong
or rigid as drill string, and therefore not as forceful. In a
horizontal well, CT often works for a few thousand feet, but, as it
extends farther into the horizontal well, its contact with the
wellbore wall increases, and with it, friction. In long horizontal
sections, the borehole wall friction becomes comparable to the
applied force, causing the CT to buckle and become ineffective.
[0003] A downhole tractor is self-powered and provides its own
conveyance mechanism. Tractors are typically used in cased wells
and can carry a heavy load to a desired location. Tractors are
designed to make short strides while pulling the load at the same
time. This is not a particularly efficient means of deployment.
[0004] There are many operations performed in or on a well after
drilling and completion operations are finished and the rig is
removed. Currently many of those operations are not closely
monitored because it is not practical to convey a logging tool into
the well while performing the particular operation. This is
especially true in highly deviated and horizontal wells.
SUMMARY
[0005] An anchor is placed in a wellbore to convey loads into a
wellbore. The anchor is placed at some desired location in a
wellbore and installed at that location using, for example, arms
that penetrate into the formation surrounding the anchor. A line
extends from the surface, wraps around a pulley in the anchor and
attaches to the downhole end of the load. Tension is applied at the
surface to the line to pull the load to a desired location in the
wellbore. Optionally, the same or a second line can be attached to
the uphole end of the load to reposition or retrieve the load.
Alternatively, a powered anchor has a line drive device and a
spool. A portion of a line extends from the anchor to the load. The
line is spooled onto the spool by the line drive device, thereby
pulling the load into the wellbore.
[0006] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] 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. Embodiments are described with
reference to the following figures. The same numbers are generally
used throughout the figures to reference like features and
components.
[0008] FIG. 1 is a schematic drawing showing an embodiment of an
anchor in a wellbore, in accordance with the present
disclosure.
[0009] FIG. 2 is a schematic drawing showing the anchor of FIG. 1
in a retracted configuration, in accordance with the present
disclosure.
[0010] FIG. 3 is a schematic drawing showing the anchor of FIG. 1
in an extended configuration, in accordance with the present
disclosure.
[0011] FIG. 4 is a schematic drawing showing an embodiment of an
anchor with a locomotion mechanism, in accordance with the present
disclosure.
[0012] FIG. 5 is a schematic drawing showing an embodiment of an
anchor on a loading dock and with a locomotion mechanism, in
accordance with the present disclosure.
[0013] FIG. 6 is a schematic drawing showing wellbore pulleys used
in conjunction with two lines and surface tensioning devices, in
accordance with the present disclosure.
[0014] FIG. 7 is a flowchart for at least one workflow embodiment,
in accordance with the present disclosure.
[0015] FIG. 8 is a schematic drawing showing a powered anchor in a
wellbore, in accordance with the present disclosure.
[0016] FIG. 9 is a schematic drawing showing a powered anchor in a
wellbore used in conjunction with a power and data cable, in
accordance with the present disclosure.
[0017] FIG. 10A is a schematic drawing showing, in cross-sectional
view, an insert having wellbore pulleys used in conjunction with
two lines and surface tensioning devices, in accordance with the
present disclosure.
[0018] FIG. 10B is a schematic drawing showing, in end view, the
insert of FIG. 10A, in accordance with the present disclosure.
DETAILED DESCRIPTION
[0019] 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.
[0020] Some embodiments will now be described with reference to the
figures. Like elements in the various figures may be referenced
with like numbers for consistency. In the following description,
numerous details are set forth to provide an understanding of
various embodiments and/or features. However, it will be understood
by those skilled in the art that some embodiments may be practiced
without many of these details and that numerous variations or
modifications from the described embodiments are possible. As used
here, the terms "above" and "below," "up" and "down," "upper" and
"lower," "upwardly" and "downwardly," and other like terms
indicating relative positions above or below a given point or
element are used in this description to more clearly describe
certain embodiments. However, when applied to equipment and methods
for use in wells that are deviated or horizontal, such terms may
refer to a left to right, right to left or diagonal relationship,
as appropriate. It will also be understood that, although the terms
first, second, etc. may be used herein to describe various
elements, these elements should not be limited by these terms.
These terms are used to distinguish one element from another.
[0021] The terminology used in the description herein is for the
purpose of describing particular embodiments only and is not
intended to be limiting. As used in the description and the
appended claims, the singular forms "a," "an" and "the" are
intended to include the plural forms as well, unless the context
clearly indicates otherwise. It will also be understood that the
term "and/or" as used herein refers to and encompasses any and all
possible combinations of one or more of the associated listed
items. It will be further understood that the terms "includes,"
"including," "comprises," and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0022] As used herein, the term "if" may be construed to mean
"when" or "upon" or "in response to determining" or "in response to
detecting," depending on the context. Similarly, the phrase "if it
is determined" or "if [a stated condition or event] is detected"
may be construed to mean "upon determining" or "in response to
determining" or "upon detecting [the stated condition or event]" or
"in response to detecting [the stated condition or event],"
depending on the context.
[0023] A system and method to provide an anchor that, once deployed
and installed in a wellbore, is capable of deploying loads into and
out of the well is disclosed. The conveyance of the anchor and the
pulling of the load are decoupled into separate steps. The anchor
may be positioned and installed, for example, at the far end of the
well (toe) and used to pull a load (e.g., a logging tool) into some
desired location in the well. The anchor may use a line connected
to the load to exert a pulling force on the load. This is in
contrast with wireline and slick line deployments which do not
provide any driving force and rely solely on the force of earth's
gravity to deploy the load into the well. The pulling force of the
anchor is also different from the forces applied by drill string or
coil tubing since their forces are pushing (compressive) rather
than pulling (tensile). The anchor may be deployed and installed
using an independent conveyance mechanism or it may be
self-propelled.
[0024] As alluded to above, an anchor is a mechanical unit that
goes to or is placed at a desired location in a generally
non-vertical section of a wellbore and attaches itself to the
borehole wall. The attachment to the wall is sufficiently strong so
that when pulling forces are applied to the anchor during
operations, the anchor itself does not move. In one embodiment, the
anchor has a pulley and line that can be used to drag a tool, for
example, along the length of the wellbore to a desired position,
including up to the anchor. For example, the anchor may have a
passive pulley that a line (e.g., slickline or wireline) can wrap
around and return to the upper end of the well. At the upper end,
in operation, a pulling force is applied to the returning or
incoming portion of the line. The line passing over the pulley has
its other (outgoing) end attached to a load (e.g., a logging tool
or any other unit to be conveyed into the borehole). The force
exerted by the incoming or returning line to the load is a pulling
force since the pulley changes the direction of the force being
applied to the incoming end.
[0025] FIG. 1 schematically shows a section of a horizontal well 12
with an anchor 14 positioned at the end (toe) of the wellbore.
Anchor 14 does not have to be installed at the end of the wellbore.
It may be deployed to any desired location in the wellbore so long
as the surrounding wellbore wall permits the anchor 14 to securely
attach at that location. The anchor 14 has a pulley 16, around
which a line 18 wraps. One end of the line, the incoming end,
extends to the upper end of well 12 and engages a drive mechanism
17, such as a motor, capable of exerting a tensile force on line
18. The other (outgoing) end of line 18 is attached to a load 19.
The arrow shown in FIG. 1 on the inbound end of line 18 (i.e.,
towards motor 17) indicates a pulling action to the left. This
force is re-directed to become a pulling force on the load 19 (to
the right), as shown by the oppositely directed arrow on line 18.
Note line 18 can form a closed loop, around or through drive
mechanism 17 and attaching to the opposite (upward) end of load 19.
Mechanism 17 can apply a tensile force to line 18 in either
direction, thereby allowing load 19 to be pulled into the wellbore
or out of the wellbore.
[0026] The embodiment of anchor 14 shown in FIG. 1 is shown in more
detail in FIG. 2. Anchor 14 comprises a support member 21. Arms 22
are rotatably attached to support member 21 and can pivot around
pivot points 23. Pivot points 23 allow the free ends of arms 22 to
extend toward or away from the wellbore wall. In this embodiment,
two arm sections 25 are shown, but the number of arm sections 25
can be one or more, depending on the maximum pulling force anchor
14 is expected to handle. Also, each arm section 25 shows two arms
22, but the number of arms 22 can be more or fewer. Pulley 24 is
attached to support member 21 and can rotate around axle 26. In the
drawing of FIG. 2, the arms 22 are shown in a closed or retracted
position which is their normal configuration during the deployment
phase (i.e., when anchor 14 is being delivered to a desired
location).
[0027] Upon reaching the desired location, arms 22 are allowed to
extend and engage the borehole wall. The extension can be effected,
for example, by a spring force on arms 22, as shown in FIG. 3. The
spring force may be triggered to apply once anchor 14 is in place,
or arms 22 may be continuously pushed radially outward by springs
32, causing the free ends or tips of arms 22 to brush against the
borehole wall while the anchor is moved towards the installation
location in the direction indicated by arrow 27. Arms 22 will
consequently rub against the borehole wall but will not attachingly
engage with the wall while the force is in the direction of arrow
27. That is, arms 22 will not attachingly engage with the wall
unless there is a force on anchor 14 in the direction indicated by
arrow 28. The length of arms 22 is chosen to be longer than the
radius of the borehole. That ensures that any particular arm 22,
when engaged with the borehole wall, will make an angle 34 with
support 21 that is less than 90 degrees. The springs 32 shown can
be of many different designs and strengths (i.e., spring
constants). Note that once a force in the direction 28 is applied
to anchor 14, the tips of arms 22 will penetrate into the formation
around the borehole wall and prevent anchor 14 from moving in the
direction 28. As larger forces are applied to anchor 14, the arms
22 will further outwardly extend and penetrate even deeper into the
formation, ensuring that anchor 14 does not move. The arm tips may
be sharpened to enhance their ability to penetrate the formation.
Other tip or arm designs may be used.
[0028] The embodiment of anchor 14 shown in FIGS. 2 and 3 is
passive in that it is delivered to the desired location by a force
acting in direction 27. Once the direction of force is switched to
direction 28, arms 22 penetratingly engage the formation to fix
anchor 14 in the wellbore. Such an anchor 14 does not need its own
source of power for its installation or operation. However, it
requires a deploying or conveyance mechanism to deploy and install
it. The deploying mechanism may be, for example, a drill string, a
tractor or CT. While those conveyance mechanisms are needed to
deploy anchor 14, they are used in the deployment/installation
phase. After that, anchor 14 can assist future deployments.
[0029] In an alternate embodiment, anchor 14 can be made more
self-contained. This may entail many different levels of
sophistication. For example, as alluded to above, in the
installation phase, the arm extension mechanism can be made to be
activated on command rather than having an active spring 32. In
this case, the arm tips are not rubbing against the formation wall
while anchor 14 is moved to the desired location. As a result,
there is less friction between anchor 14 and the borehole wall,
which makes it easier to deploy anchor 14 to the desired location.
The arm extension mechanism may be powered by a battery, for
example, or anchor 14 may be attached to a power cable at the time
of installation and extension. Unless it is desired to have power
available on anchor 14 for other purposes, once anchor 14 is in
place and operational, the power cable can be disconnected and
removed (i.e., pulled back to the surface).
[0030] Unlike tractors that carry a load with them while they move
in the borehole, anchor 14 carries a minimum load while being
deployed. During deployment, the forces involved include the weight
of anchor 14 and the weight of line 18 (and their corresponding
frictional forces). To ease the deployment further, a lightweight
temporary line or leader 45 can be used in the deployment phase
(see FIG. 4). Once installation is complete, the temporary line or
leader 45 can be used to convey the operational line 18 in
place.
[0031] Anchor 14 may additionally be equipped with a locomotion
mechanism. An example is shown in FIG. 4, wherein an electric motor
(not shown) is used to drive a belt 43 (via wheels 42), enabling
anchor 14 to traverse well 12. More specifically, in the embodiment
of FIG. 4, a carrier 41 is used to carry anchor 14 to some desired
location in the wellbore. Carrier 41 is equipped with wheels 42
which are rotated by a motor (not shown) which in turn is powered
by an electrical line (not shown) or battery. The rotation of
wheels 42 causes rotation of a belt 43 (similar to what is used in
a bulldozer or snow mobile, for example), which then causes the
carrier to move along the length of the borehole. Thus, anchor 14
may be self-propelled. As stated above, leader 45 represents a
temporary line in this particular embodiment, but may also
represent operational line 18 in an alternate embodiment that does
not use a leader 45.
[0032] In an alternate embodiment, leader 45 is not attached to
anchor 14 while anchor 14 is carried to its desired location.
Rather, temporary line 45 (or line 18) is conveyed to anchor 14 by
a second trip of carrier 41 and installed. Carrier 41 may be an
integral part of anchor 14. In this unitary embodiment, anchor 14
can be retrieved, if desired, by driving carrier 41 in the reverse
direction.
[0033] In yet another alternate embodiment, carrier 41 is
independent from anchor 14 and may be pulled out of the well once
anchor 14 is installed in the desired location. That is, in the
embodiment shown in FIG. 5, carrier 41 has a loading dock 46 on
which to place anchor 14 while deploying anchor 14 to its desired
location. Once at that location, anchor 14 is released and carrier
41 is pulled back. In the embodiments of FIGS. 4 and 5, arms 22
remain in the closed position while anchor 14 is delivered to the
desired location. Also, loading dock 46 has, in the embodiment
shown, non-driven wheels 47 on which it rolls.
[0034] In addition to pulley 16 (or 24), which is joined to support
member 21 of anchor 14, there may optionally be other, additional
pulleys to facilitate the movement of line 18 along the length of
the well 12. FIG. 6 shows an example wherein multiple additional
pulleys (e.g., 61, 62) are placed in the well. Since horizontal
wells generally are drilled by starting with a vertical section of
the well before sidetracking into a deviated section of the well
and eventually transitioning to a horizontal section, additional
pulleys 61, 62 may be placed at the transition zones, such as the
end of vertical section or the beginning of the horizontal
section.
[0035] In one implementation of this embodiment, a first line 74 is
wrapped around a first winch 65 at an uphole location. First line
74 is passed over a surface pulley 63 which is located over the
borehole opening. First line 74 passes through vertical section 66
of the well before reaching additional pulley 62, which is located
(in this embodiment) at the transition between the vertical section
66 and the deviated section 67 of the well. First line 74 is placed
over additional pulley 62. Having first line 74 ride on additional
pulley 62 helps reduce the contact between first line 74 and the
borehole wall. Such contact is avoided since it may lead to erosion
of the borehole wall and first line 74, in addition to producing
undesirable frictional drag. First line 74 extends through the
deviated section 67 of the well until it reaches the transition
between the deviated section 67 and the horizontal section 68 of
the well. Here additional pulley 61 is installed to guide first
line 74. The additional pulleys 61, 62 are small enough so as not
to restrict the movement of a load 69 through the well.
[0036] First line 74 extends to and wraps around pulley 16 of
anchor 14, before extending back uphole and reaching the downhole
end 72 of load 69. First line 74 may be used to pull load 69 toward
or to the end of the well. There may also be a second line 76 that
may be used to pull load 69 out of the well. Second line 76 is
attached to the uphole end 71 of load 69 and extends to an uphole
location. Similar to that described above, further additional
pulleys 78, 79 may be positioned more or less diametrically
opposite additional pulleys 61, 62, respectively, to guide second
line 76. Second line 76 engages and travels on additional pulleys
78, 79 and ultimately passes over another surface pulley 63 and
wraps around a second winch 64. Additional pulleys 78, 79 serve in
a capacity similar to additional pulleys 61, 62 (i.e., reduce
friction and erosion). While in the embodiment shown additional
pulleys 61, 62, 78, 79 are installed more or less pairwise (i.e.,
61/78, 62/79) diametrically across the wellbore, other
configurations are possible.
[0037] FIGS. 10A and 10B show, in cross-section and end view,
respectively, an embodiment in which an insert 1010 may be
delivered to and disposed in a specific location in the well, such
as where pulley 61 of FIG. 6 is located. In the embodiment shown in
FIGS. 10A and 10B, insert 1010 has a cylindrical shell frame 1020
that has substantially the same outer diameter as the diameter of
the well and can be anchored to the borehole wall (not shown).
Insert 1010 comprises at least one pulley (e.g., the one labeled 61
since it serves the equivalent role in this embodiment as pulley 61
of FIG. 6) that can be used to guide and support line 74, which is
located at or near the ceiling of the well. Line 74 may be caged
and supported by a cover 1030 to prevent line 74 from becoming
misaligned with pulley 61 when line 74 is not in tension. When line
74 is pulled, tension in the line causes it to engage the groove of
pulley 61. Insert 1010 may contain an additional pulley 78 on or
near the floor of the well that guides and supports line 76. In
this case, line 76 runs between pulley 78 and cylindrical frame
1020. A cover 1030 may be used with pulley 78, but the pulley
structure tends to keep line 76 reasonably aligned with pulley 78
and a tensile load in line 76 tends to pull it into engagement with
pulley 78. Multiple inserts 1010 may be disposed in the well.
[0038] Operationally, for the embodiment of FIG. 6, before load 69
is introduced into the well, first line 74 is run from the winch
65, through the pulleys (e.g., 63, 62, 61), and back to the uphole
location. Note, at this point, all of second line 76 is wrapped
around second winch 64. The free end of first line 74 is attached
to what will be the downhole end 72 of load 69 and the free end of
second line 76 is attached to what will be the uphole end 71 of
load 69. Load 69 is introduced into the well while it is being
supported (via tension) by second line 76. The earth's gravity
helps load 69 slide to, or at least close to, the lower end of
deviated section 67. While that is happening, first line 74 is not
providing any pulling force unless there is a restraining force
(such as that arising from traversing a dogleg, for example) that
necessitates more force than that already provided by gravity. Once
load 69 gets to a position where it cannot go any farther without
assistance, second line 76 is made loose (slack) so that it does
not impede any further downward motion of load 69. At the same
time, first line 74 is tightened, causing a pulling force on load
69. This is continued until load 69 reaches its desired location in
the well. The process of removing load 69 out of the well is the
reverse. First line 74 is made loose while second line 76 is
tightened and pulled. This moves load 69 in the uphole direction.
This is continued until load 69 reaches the uphole location.
[0039] In another embodiment, the drive mechanism 17 located uphole
in the above-described embodiment may be moved downhole. For
example, drive mechanism 17 may be lowered into the well and
allowed to descend until it reaches a certain depth (e.g., the
bottom of the vertical section--this may be at or near the same
location as additional pulley 62). With this arrangement, the
number of additional pulleys may be reduced and the rubbing contact
of the line (18 or 76) against the borehole wall further minimized.
This would reduce the friction between the line and the wall and
also minimize any erosion or sticking of the line to the borehole
wall.
[0040] Lines 74 and 76 (both or only one) may be purely mechanical
and used to pull load 69 in or out of the well. In this case, the
line (74 and/or 76) is generally lighter and easier to move through
the well compared to heavier electro-mechanical cables. If solely
mechanical lines are used, the tools or instruments that are part
of load 69 that require electrical power may be operable using
batteries. Further, the data measured by those devices is not
available in real-time. The data can be downloaded after the
operation is complete and the load 69 is brought to the
surface.
[0041] In an alternate embodiment, at least one of the lines (74,
76) is a wireline that can be used to provide power and telemeter
(i.e., electronically transfer) data. A wireline is generally heavy
and somewhat inflexible and is therefore generally more appropriate
to be the second line 76.
[0042] Anchor 14 may have centralizers to center itself within the
wellbore while or before the arms are released. That helps ensure
that the pulling load is evenly distributed over the different arms
22 for best pulling resistance.
[0043] In yet another embodiment, shown in FIG. 8, a powered anchor
80 comprises a mechanism to generate a pulling force. In this
embodiment, powered anchor 80 contains a line drive device 82
having, for example, an electric motor and gear system. Line drive
device 82 can be used to pull a load (downhole) and store a line 86
within powered anchor 80. Powered anchor 80 does not require a
separate driving mechanism located uphole, such as a surface winch,
and as a result there is no need for a pulley or a dedicated line
going from powered anchor 80 directly to the surface location. That
is, powered anchored 80, shown at the end of a horizontal well in
FIG. 8, is self-contained. The electric motor in line drive device
82 may be powered from uphole. Power may be delivered to powered
anchor 80 through line 86, for example. Line 86 is used to pull the
load in the downhole direction and, as such, is strong enough to
handle the corresponding forces. A power line (not shown) may be
placed in a space in the interior region of line 86 for power
transfer to powered anchor 80. The technique of making line 86 with
electrical wire and logic wires is well known in the wireline art.
A first end of line 86 attaches to powered anchor 80. Electrical
power and/or commands can be extracted and used to operate powered
anchor 80. A second part of line 86 is attached to (or near) the
downhole end of a load. Line 86 may extend through or around the
load, be secured to (or near) the uphole end of the load, and
continue uphole to the surface. Line 86 may be joined to an uphole
drive mechanism such that line 86 may be used to withdraw the load
(with line drive device 82 in neutral or reverse).
[0044] As stated above, the electric motor and other mechanical and
electrical components needed to operate powered anchor 80 are
housed in line drive device 82 of powered anchor 80. While a load
is pulled toward powered anchor 80, line 86 wraps around a spool 84
for storage. The wrapping can be done in multiple layers to save
space. The maximum length of line available depends on the storage
capacity of powered anchor 80. Storage capacity factors include,
but are not limited to, the length of spool 84, the diameter of
spool 84, and the number of layers of line 86 wrapped around spool
84. The last factor depends on, among other things, the diameter of
line 86 and the space between spool 84 and the borehole wall. These
parameters may be adjusted to produce a desired line length.
[0045] Like the passive embodiments described above, powered anchor
80 may have multiple arms 81 that are longer than the radius of the
well and serve to secure powered anchor 80 in the well.
[0046] FIG. 9 shows an alternate embodiment in which powered anchor
80 may be connected both mechanically to a load 69 and electrically
to an uphole device (not shown). Load 69 may be pulled in two
directions using two lines (86, 88). Line 86 may be used by powered
anchor 80 to pull load 69 deeper into the well. Line 88 may be used
to pull load 69 in the uphole direction. In the embodiment shown,
both lines are equipped to provide electrical power and command
lines. Provisions may be made in the structure of load 69 to
connect the power and command lines of lines 88 and 86. When the
load 69 is a logging tool, for example, the connectivity is
generally already built into the tool since those tools are
commonly designed to accept and transfer electrical power and data
from and to other apparatuses above and below the tool. For other
loads, such as a container of acid for matrix acidization, for
example, wiring 89 from one side of load 69 to the other, along
with connectors on each side of load 69, can provide the desired
connectivity.
[0047] In a typical deployment scenario, line 86 is connected to
the downhole side of load 69. The upper portion of line 88 is
spooled on a surface winch 64, and the free (downhole) end is
connected to the uphole end of load 69. Load 69 is allowed to enter
the well and make a controlled fall under earth's gravity, during
which time line 88 is extended and line 86 is spooled. When load 69
reaches a dogleg or the end of its controlled fall, line drive
device 82 in powered anchor 80 provides the force to pull load 69
towards powered anchor 80 via line 86. Pulling load 69 out of the
well is performed by reversing the forces on lines 88 and 86. Here
line 86 is made slack while line 88 is pulled with sufficient force
to move load 69 in the uphole direction.
[0048] Attention is now directed to processing procedures, methods,
techniques, and workflows that are in accordance with some
embodiments. Some operations in the processing procedures, methods,
techniques, and workflows disclosed herein may be combined and/or
the order of some operations may be changed. It is important to
recognize that geologic interpretations, sets of assumptions,
and/or domain models may be refined in an iterative fashion. This
concept is applicable to the processing procedures, methods,
techniques, and workflows discussed herein. This iterative
refinement can include use of feedback loops executed on an
algorithmic basis, such as at a computing device and/or through
manual control by a user who may make determinations regarding
whether a given step, action, template, or model has become
sufficiently accurate.
[0049] FIG. 7 shows a flowchart illustrating an embodiment in
accordance with this disclosure. In this embodiment, the workflow
comprises disposing an anchor in a first desired location in a
wellbore (702); installing the anchor into a formation surrounding
the anchor (704); using a line moveably constrained by the anchor
to pull a load to a second desired location in the wellbore (706);
and optionally, using the line to reposition or retrieve the load
(708).
[0050] 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
scope of the present disclosure, and that they may make various
changes, substitutions, and alterations herein without departing
from the scope of the present disclosure.
[0051] 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.
[0052] While only certain embodiments have been set forth,
alternatives and modifications will be apparent from the above
description to those skilled in the art. These and other
alternatives are considered equivalents and within the scope of
this disclosure and the appended claims. Although only a few
example embodiments have been described in detail above, those
skilled in the art will readily appreciate that many modifications
are possible in the example embodiments without materially
departing from this invention. Accordingly, all such modifications
are intended to be included within the scope of this disclosure as
defined in the following claims. 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. It is the express intention of the applicant not to
invoke 35 U.S.C. .sctn.112, paragraph 6 for any limitations of any
of the claims herein, except for those in which the claim expressly
uses the words `means for` together with an associated
function.
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