U.S. patent application number 17/715314 was filed with the patent office on 2022-07-28 for opening a casing with a hydraulic-powered setting tool.
This patent application is currently assigned to GEODYNAMICS, INC.. The applicant listed for this patent is GEODYNAMICS, INC.. Invention is credited to John T. Hardesty, Dennis Roessler.
Application Number | 20220235631 17/715314 |
Document ID | / |
Family ID | 1000006244922 |
Filed Date | 2022-07-28 |
United States Patent
Application |
20220235631 |
Kind Code |
A1 |
Hardesty; John T. ; et
al. |
July 28, 2022 |
OPENING A CASING WITH A HYDRAULIC-POWERED SETTING TOOL
Abstract
A setting tool (400) for opening and closing a sleeve (210)
inside a casing (200) includes a body (402) extending along a
central longitudinal axis (X); a set of holding dogs (420) located
around the body (402); and a set of sleeve dogs (430) located
around the body (402). The set of sleeve dogs (430) are configured
to move along the central longitudinal axis (X) relative to the set
of holding dogs (420).
Inventors: |
Hardesty; John T.; (Fort
Worth, TX) ; Roessler; Dennis; (Fort Worth,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GEODYNAMICS, INC. |
Millsap |
TX |
US |
|
|
Assignee: |
GEODYNAMICS, INC.
Millsap
TX
|
Family ID: |
1000006244922 |
Appl. No.: |
17/715314 |
Filed: |
April 7, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16635263 |
Jan 30, 2020 |
11333003 |
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PCT/US2018/022841 |
Mar 16, 2018 |
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17715314 |
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62540333 |
Aug 2, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/26 20130101;
E21B 2200/06 20200501; E21B 34/14 20130101; E21B 23/03
20130101 |
International
Class: |
E21B 34/14 20060101
E21B034/14; E21B 23/03 20060101 E21B023/03; E21B 43/26 20060101
E21B043/26 |
Claims
1. A setting tool (400) for opening and closing a sleeve (210)
inside a casing (200), the setting tool (400) comprising: a body
(402) extending along a central longitudinal axis (X); a set of
holding dogs (420) located around the body (402); and a set of
sleeve dogs (430) located around the body (402), wherein the set of
sleeve dogs (430) are configured to move along the central
longitudinal axis (X) relative to the set of holding dogs
(420).
2. The setting tool of claim 1, further comprising: a holding ram
(422) configured to slid under the set of holding dogs (420) to
move the holding dogs radially away from the central longitudinal
axis.
3. The setting tool of claim 2, further comprising: a holding
piston (424) located inside the body and configured to move the
holding ram along the central longitudinal axis.
4. The setting tool of claim 1, further comprising: a sleeve ram
(432) configured to slid under the set of sleeve dogs (430) to move
the sleeve dogs radially away from the central longitudinal
axis.
5. The setting tool of claim 4, further comprising: a first sleeve
piston (434) located inside the body and configured to move the
sleeve ram along the central longitudinal axis relative to the set
of sleeve dogs.
6. The setting tool of claim 5, further comprising: a second sleeve
piston (438) located inside the body and configured to move the
sleeve ram together with the set of sleeve dogs along the central
longitudinal axis to open or close the sleeve.
7. The setting tool of claim 1, further comprising: a seal (440)
located around the body (402) and configured to seal an inside of
the casing so that a fracturing fluid reaches the set of sleeve
dogs and the set of holding dogs but not an adjacent casing located
downstream from the current casing.
8. The setting tool of claim 1, further comprising: an accumulator
(480) that stores fluid under pressure and is configured to actuate
a holding piston, a first sleeve piston and a second sleeve piston
for moving the set of holding dogs and the set of sleeve dogs.
9. The setting tool of claim 8, wherein the holding piston, the
first sleeve piston and the second sleeve piston are concentric to
each other.
10. The setting tool of claim 1, further comprising: a hydraulic
valve block (406) that includes plural valves for controlling a
movement of a holding piston, a first sleeve piston and a second
sleeve piston.
11. The setting tool of claim 10, wherein the hydraulic valve block
includes solenoids.
12. The setting tool of claim 11, wherein the hydraulic valve block
includes batteries for actuating the solenoids and a controller for
controlling the solenoids.
13. The setting tool of claim 12, further comprising: an electronic
module that includes a velocity sensor and a pressure
transducer.
14. The setting tool of claim 13, further comprising: a fishing
neck so that a retrieving tool connects to the fishing neck for
retrieving the setting tool from the well.
15. A system (200, 400) for fracturing a well, the system
comprising: a casing (200) having plural openings (212) that are
covered by a sleeve (210) when the sleeve is in a close position;
and a setting tool (400) configured to open the sleeve (210) for
fracturing operations, wherein the setting tool (400) includes, a
body (402) extending along a central longitudinal axis (X), a set
of holding dogs (420) located around the body (402), and a set of
sleeve dogs (430) located around the body (402), wherein the set of
sleeve dogs (430) are configured to move along the central
longitudinal axis (X) relative to the set of holding dogs
(420).
16. The system of claim 15, wherein the setting tool further
comprises: a holding ram (422) configured to slid under the set of
holding dogs (420) to move the holding dogs radially away from the
central longitudinal axis.
17. The system of claim 16, wherein the setting tool further
comprises: a holding piston (424) located inside the body and
configured to move the holding ram along the central longitudinal
axis.
18. The system of claim 15, wherein the setting tool further
comprises: a sleeve ram (432) configured to slid under the set of
sleeve dogs (430) to move the sleeve dogs radially away from the
central longitudinal axis.
19. The system of claim 18, wherein the setting tool further
comprises: a first sleeve piston (434) located inside the body and
configured to move the sleeve ram along the central longitudinal
axis relative to the set of sleeve dogs.
20. The system of claim 19, wherein the setting tool further
comprises: a second sleeve piston (438) located inside the body and
configured to move the sleeve ram together with the set of sleeve
dogs along the central longitudinal axis to open or close the
sleeve.
Description
BACKGROUND
Technical Field
[0001] Embodiments of the subject matter disclosed herein generally
relate to downhole tools for perforating operations, and more
specifically, to a casing string having one or more casing valves
that are opened and closed with a hydraulic-powered setting tool
for fracturing a desired formation.
Discussion of the Background
[0002] After a well 100 is drilled to a desired depth H relative to
the surface 110, as illustrated in FIG. 1, and the casing string
110 protecting the wellbore 104 has been installed and cemented in
place, it is time to connect the wellbore 104 to the subterranean
formation 106 to extract the oil and/or gas.
[0003] The typical process of connecting the casing to the
subterranean formation may include the following steps: (1) placing
a plug 112 with a through port 114 (known as a frac plug) above a
just stimulated stage 116, and (2) perforating a new stage 118
above the plug 112. The step of perforating is achieved with a gun
string 120 that is lowered into the well with a wireline 122. A
controller 124 located at the surface controls the wireline 122 and
also sends various commands along the wireline to actuate one or
more gun assemblies of the gun string.
[0004] A traditional gun string 120 includes plural carriers 126
connected to each other by corresponding subs 128, as illustrated
in FIG. 1. Each sub 128 includes a detonator 130 and a
corresponding switch 132. The corresponding switch 132 is actuated
by the detonation of a downstream gun. When this happens, the
detonator 130 becomes connected to the through line, and when a
command from the surface actuates the detonator 130, the upstream
gun is actuated. This process is expensive, time consuming and
dangerous as the gun includes shaped charges, which include
explosive materials.
[0005] U.S. Pat. No. 6,763,892 discloses a different approach for
fracturing a well, in which the individual casing tubes forming the
casing string are provided with a corresponding sliding sleeve,
i.e., a casing valve. The sliding sleeve can be opened or closed as
desired with the help of a plurality of seals and ports. The
fracturing of the formation around the casing can then be performed
through the openings formed in the casing string.
[0006] However, this specific implementation is burdensome because
the casing valve includes a number of individual components that
are threaded to each other and use plural seals, which may fail and
leak. In addition, this specific implementation cannot withstand
the torque specifications of a typical wellbore casing because of
the threaded components.
[0007] Thus, there is a need to provide a casing valve that can
withstand the torque specifications in the wellbore casing, is not
prone to leaks and is easy to open and close when a fracturing
operation is desired.
SUMMARY
[0008] According to an embodiment, there is a setting tool for
opening and closing a sleeve inside a casing. The setting tool
includes a body extending along a central longitudinal axis (X), a
set of holding dogs located around the body, and a set of sleeve
dogs located around the body. The set of sleeve dogs are configured
to move along the central longitudinal axis (X) relative to the set
of holding dogs.
[0009] According to another embodiment, there is system for
fracturing a well. The system includes a casing having plural
openings that are covered by a sleeve when the sleeve is in a close
position, and a setting tool configured to open the sleeve for
fracturing operations. The setting tool includes a body extending
along a central longitudinal axis (X), a set of holding dogs
located around the body, and a set of sleeve dogs located around
the body. The set of sleeve dogs are configured to move along the
central longitudinal axis (X) relative to the set of holding
dogs.
[0010] According to still another embodiment, there is a method for
fracturing a well. The method includes lowering a setting tool
inside a casing having plural openings covered by a sleeve,
engaging a set of holding dogs of the setting tool with a
corresponding holding groove formed inside the casing, engaging a
set of sleeve dogs of the setting tool with a corresponding sleeve
groove formed in the sleeve, and opening the sleeve by translating
the sleeve dogs along a central longitudinal axis X, relative to
the holding dogs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate one or more
embodiments and, together with the description, explain these
embodiments. In the drawings:
[0012] FIG. 1 illustrates a well and associated equipment for well
completion operations;
[0013] FIG. 2 illustrates a casing having a sleeve;
[0014] FIG. 3 illustrates a casing string that ends with a toe
valve;
[0015] FIG. 4 illustrates a setting tool for opening the sleeve in
the casing;
[0016] FIG. 5A illustrates the setting tool without holding dogs,
sleeve dogs and a seal while FIG. 5B illustrates the addition of
these elements to the setting tool;
[0017] FIG. 6 illustrates the setting tool provided inside the
casing;
[0018] FIG. 7 illustrates the setting tool engaging the casing with
the holding dogs;
[0019] FIG. 8 is a flowchart of a method for opening the sleeve of
the casing and fracturing a stage associated with the casing;
[0020] FIG. 9 illustrates the setting tool engaging the casing with
the holding dogs and the sleeve dogs;
[0021] FIG. 10 illustrates the setting tool opening the sleeve;
[0022] FIG. 11 illustrates the setting tool closing the sleeve;
[0023] FIG. 12 illustrates the setting tool disengaging the
casing;
[0024] FIG. 13 illustrates the setting tool moving to the next
casing;
[0025] FIG. 14 illustrates an accumulator and fail safe mechanism
of the setting tool;
[0026] FIG. 15 is a flowchart of a method for opening the sleeve of
the casing; and
[0027] FIGS. 16A to 16C illustrate a flowchart of a method for
opening the sleeve, fracturing the stage associated with a casing,
closing the sleeve and then repeating this operation for all the
casings in the casing string.
DETAILED DESCRIPTION
[0028] The following description of the embodiments refers to the
accompanying drawings. The same reference numbers in different
drawings identify the same or similar elements. The following
detailed description does not limit the invention. Instead, the
scope of the invention is defined by the appended claims. The
following embodiments are discussed, for simplicity, with regard to
a casing having a valve and a hydraulic-powered setting tool that
opens and closes the casing valve. However, the embodiments
discussed herein are also applicable to a device that has a valve
that needs to be closed and opened under tight conditions.
[0029] Reference throughout the specification to "one embodiment"
or "an embodiment" means that a particular feature, structure or
characteristic described in connection with an embodiment is
included in at least one embodiment of the subject matter
disclosed. Thus, the appearance of the phrases "in one embodiment"
or "in an embodiment" in various places throughout the
specification is not necessarily referring to the same embodiment.
Further, the particular features, structures or characteristics may
be combined in any suitable manner in one or more embodiments.
[0030] According to an embodiment illustrated in FIG. 2, a casing
200 (sometimes called a casing valve) has an interior sleeve 210.
Interior sleeve 210 has plural sleeve openings 212 that corresponds
to plural casing openings 214 formed in the body 216 of the casing
200. The sleeve 210 is shown closed in FIG. 2, i.e., a fluid 220
inside the casing 200 cannot move outside the body 216 through
casing openings 214. However, if the sleeve 210 is moved to the
left and the sleeve openings 212 are aligned with the casing
openings 214, then the fluid 220 communicates with the outside 222
of the casing. Note that an interior diameter of the sleeve 210 is
larger than a diameter of a seal region 227 so that the sleeve
cannot enter the seal region for reasons to be discussed later.
Further note that an interior of body 216 has a latching groove 224
and an interior of sleeve 210 has a latching groove 226, also to be
discussed later. A set of latching grooves 224 are formed inside
the seal region 227 and the other set of latching grooves 226 are
formed onto the sleeve 210.
[0031] Plural casings 200A and 200B (only two are shown for
simplicity, but a casing string may include tens or hundreds of
casings) are shown in FIG. 3 distributed in the well 100. The last
casing 200A is connected to a tow valve 201. Just before the
fracturing operation, all the valves (sleeves) are closed. The toe
valve 201 (an example of which is described in U.S. Pat. Nos.
9,121,247, 9,121,252, and 9,650,866) has a disk that breaks when
the pressure inside the casing becomes larger than a certain
threshold pressure. When this happens, a piston inside a wall of
the toe valve is actuated and moves to open the openings 201A
formed through the toe valve. In this way, the toe valve stage may
be fractured by the fluid 230 pumped from the surface. A wiper plug
232 has been previously pumped to the bottom of the well, past the
toe valve 201 for preventing the fracturing fluid 230 to move past
the toe valve. After the fracturing operation of the toe valve
stage is finalized, the toe valve may be used to expel the pumped
fluid into the formation.
[0032] To reveal the openings of the top casing of the casing
string, a hydraulic-powered setting tool is placed into the well
and controlled to attach to the sleeve of the casing. According to
an embodiment illustrated in FIG. 4, the hydraulic-powered setting
tool (setting tool herein) 400 has a body 402 connected to a
hydraulic valve block 404 that includes plural valves 406. Valves
406 are configured to allow in and out a fluid under pressure to
activate various pistons as discussed later. In one embodiment,
there are three different pistons that need to be actuated and each
piston is actuated by a pair of valves. For this reason, the figure
shows 6 valves. However, one skilled in the art would understand
that more or less valves may be used for the setting tool.
[0033] Setting tool 400 also includes a first set of connecting
elements 420, called herein holding dogs because these elements
would engage corresponding grooves in the casing valve and fix the
setting tool relative to the casing. The setting tool also includes
a second set of connecting elements 430, called herein sleeve dogs
because these elements would engage the sleeve of the casing valve
and move it from the closed position to the open position and vice
versa. The dogs are mechanical elements that mate with
corresponding grooves formed in the body of the casing and/or the
sleeve.
[0034] The setting tool 400 further includes a seal 440, located
downstream from the first and second set of dogs. The setting tool
400 further includes an electronics module 450 and a fishing neck
452. The electronics module 450 includes various sensors, e.g.,
pressure transducer 454, velocity sensor 456, accelerometers, etc.,
that may be connected to a wireline for communicating and/or
receiving various information to the surface. The hydraulic valve
block 404 may include similar or additional sensors. In one
application, the hydraulic valve block 404 includes a pressure
transducer 408 and a power source 410. The power source 410 may
include one or more batteries. In one application, the power source
410 includes about 100 AA lithium batteries. The hydraulic valve
block 404 may also include a controller 412, that is connected to
the various sensors noted above and which is configured to open and
close one or more or the valves 406 so that a corresponding piston
moves up and down the well.
[0035] In one application, the setting tool shown in FIG. 4 may be
used for different sized casing. For example, the casing may have
an internal diameter of 41/2'' or 51/2''. Irrespective of the
internal diameter of the casing, the setting tool shown in FIG. 4
may be provided with corresponding dogs and seals to account for
the change in diameter of the casing. In this respect, FIG. 5A
shows the location A of the setting tool 400 having no sets of dogs
420 or 430 and no seal 440. After determining the internal diameter
of the casing in which the setting tool is to be deployed, the
corresponding sets of dogs 420 and 430 and the seal 440 are added
(slid from one end of the tool) to the body 402 of the setting
tool, as illustrated in FIG. 5B.
[0036] Once the sets of dogs are in position, they are attached to
corresponding pistons (to be discussed later) and can be moved
relative to the body of the casing, both toward or away (i.e.,
radially) from a central longitudinal axix X of the body and also
along the central longitudinal axis X. To move the dogs radially
along axis X, ramps are sliding under the dogs and the ramps are
powered by the pistons noted above. The pistons in turn are
actuated with hydraulics, provided through the valves 406. In one
application, instead of using hydraulics and solenoids for
actuating the pistons, it is possible to use electrical motors with
power screws. The hydraulics energy is supplied by the pressure
established inside the casing. For this reason, the setting tool
includes one or more accumulators (e.g., spring-loaded
accumulators) that can store enough hydraulic energy to open and
close several casing valve sleeves. The setting tool may use
solenoid valves 406 for reducing the electrical energy required to
open and close the valves. These pistons are shown and discussed in
the next figures.
[0037] FIG. 6 shows a casing 200 (considered to be the top casing
in the casing string) having inside the setting tool 400. The
holding dogs 420, the sleeve dogs 430 and seal 440 of the setting
tool 400 are shown in cross-section. Also visible are the holding
grooves 224 of the casing 200 and the sleeve grooves 226 of the
sleeve 210. The aim of this embodiment is to connect the set of
holding dogs 420 to the corresponding holding groove 224 to
fix/hold the setting tool inside the casing 200, and then to
connect the set of sleeve dogs 430 to the sleeve groove 226 to take
control of the sleeve 210. In this way, the sleeve dogs 430 may be
moved relative to the holding dogs 420 to open and close the sleeve
210 for fracturing the stage associated with the top most casing.
After the fracturing operation is finalized, the sleeve 210 is
closed and the sleeve dogs and holding dogs are disengaged from
their respective grooves so that the setting tool 400 can move to
the next casing to repeat the above operations and fracture the
stage associated with the next casing. Because the sleeves of all
the casings are closed except for the sleeve of the current casing
in which the setting tool is deployed, the fracturing is controlled
to take place only in the current stage.
[0038] FIG. 6 also shows holding dogs ramps 422 and sleeve dogs
ramps 432. These ramps can move along the longitudinal direction X
of the casing 200, to make the corresponding dogs to move along the
radial direction R. Ramps 422 are actuated by piston 424 while
ramps 432 are actuated by piston 434 (see FIG. 7). FIG. 6 also
shows the sleeve 210 having plural sleeve openings 212 and the
casing 200 having plural casing openings 214. Note that the two
sets of openings are not aligned in FIG. 6, which means that the
sleeve is closed and no fluid from inside the casing can fracture
the formation 106 around the casing.
[0039] A method for moving the setting tool inside the casing,
engaging the holding dogs followed by the sleeve dogs, and opening
the sleeve of the casing for fracturing operations is now discussed
with regard to FIG. 8. In step 800, the setting tool 400 is
provided inside the casing 200, as illustrated in FIG. 6. The
process starts with the top casing and then moves to the next
casing, toward the bottom of the well, until all the casings are
fractured. Those skilled in the art would understand that because
of the autonomy of the setting tool, the operator can fracture
selected stages, i.e., only selected casing valves can be opened
for fracturing.
[0040] In step 802, a top portion 420A (see FIG. 7) of the holding
dogs 420 is engaged with the holding groove 224. This engagement
takes place as the holding dogs 420 are biased by springs 426
(toward the central part of the setting tool along the radial
direction) and because the holding ramp 422 was moved by the
corresponding piston 424 to push the holding dogs along the radial
direction R, toward the outside of the casing 200. In this regard,
note that a bottom region 420B of the holding dogs 420 are located
on top of ramp 422 in FIG. 7 while FIG. 6 shows the same bottom
region of the holding dogs at the bottom of the ramp. Thus, the
movement of the ramp 422 because of the piston 424 has pushed the
holding dogs toward the interior wall of the casing 200 and when
the top region 420A of the holding dogs 420 has met the
corresponding holding groove 224, the two elements have locked in
place as shown in FIG. 7. To prevent the top region 420A of the
holding dogs 420 to engage with the sleeve groove 226 as the
setting tool is travelling through the casing, a size of the sleeve
groove 226 is larger than a size of the top region 420A so that the
holding dogs 420 cannot engage with the sleeve groove 226. Note
that at this time the sleeve 210 is still closing the casing
openings 214. Also note that at this time the seal 440 is abutting
tightly against the internal wall 200A of the casing 200, thus in
effect isolating the stage corresponding to the current casing 200
from the rest of the stages associated with other casings.
[0041] The movement of the pistons is controlled by the processor
412, valves 406, and at least an accumulator that stores hydraulic
energy as now discussed. When the setting tool is approaching the
top most casing, the operator of the setting tool may send a signal
along the wireline to the processor 412 for moving the holding dogs
along the radial direction. Upon receiving this command, processor
412 opens one of the valves 406, which corresponds to piston 424,
and allows the pressurized fluid inside the accumulator to move the
piston along the longitudinal axis X, as illustrated by the
corresponding arrow in FIG. 6, to move the ramp 422 under the
holding dogs. As the setting tool is moving through the casing 200,
the holding dogs 420 eventually engage the holding groove 226. At
this time, the setting tool stops and the velocity sensors 456
determine that the setting tool has stopped. Processor 412 then
choses valve 406 and may inform the operator of the well that the
setting tool is set. When the setting tool is set, the pressure
above it increases, which signals to the operator to stop pumping
the setting tool.
[0042] In step 804, the sleeve dogs 430 are engaged with the
corresponding sleeve grooves 226. Because controller 412 has
determined that the setting tool has stopped and knowing that the
holding dogs are engaged, it can instruct the sleeve dogs 430 to
engage the sleeve groove 226. In this regard, note that in FIG. 7
the ramp 432 is not biasing the sleeve dogs 430 along the radial
direction. However, FIG. 9 shows the ramp 432 has moved along the
longitudinal direction X due to piston 434 (which is controlled by
processor 412 and corresponding valve 406), so that a top region
430A of the sleeve dogs 430 is engaged with the sleeve groove 226
and a bottom region 430B of sleeve dogs 430 has moved up the ramp
432. At this time, the holding dogs are holding the setting tool
fixed relative to the casing and the sleeve dogs have engaged the
sleeve and are ready to move the sleeve along the longitudinal axis
X.
[0043] In step 806, the sleeve 210 is opened as illustrated in FIG.
10. To move the sleeve dogs 430, another piston 438 (a second
piston) is used. This second piston 438 is associated with the
sleeve dogs 430 and moves not only the sleeve dogs as illustrated
in FIG. 10, but also the ramp 432. Due to the movement of the
sleeve dogs 430 relative to the holding dogs 430 and implicitly
relative to the casing 200, the sleeve 210 moves along the
longitudinal axis X, toward the left in the figure, so that the
sleeve openings 212 become aligned with the casing openings 214.
The movement of the second piston 438 is coordinated by controller
412 and achieved by corresponding hydraulic valve 406.
[0044] In step 808, the fracturing fluid is pumped from the casing
and exits through aligned openings 212 and 214 into the formation
106, as indicated by arrow B in FIG. 10. Note that due to the seal
440, which abuts against the internal wall of the casing 200, no
sand or other formation debris from the formation passes the seal
toward the other casing valves. Thus, the setting tool can freely
move toward the other casing valves after finalizing the fracturing
of the current stage.
[0045] When the fracturing operation is concluded for the current
stage, the sleeve 210 needs to be moved back to the closed
position, to close the sleeve openings 212. Thus, in step 810, the
sleeve is closed. To instruct the controller 412 to close the
sleeve, the following mechanism may be used. Suppose that the
operator of the well has finalized the fracturing operation. The
operator may send a signal to the controller 412 for closing the
sleeve. The signal may be transmitted in various ways, i.e., as an
electrical signal along a wire, as an acoustic signal with a modem,
etc. The embodiment presented in FIG. 10 uses the following
mechanism. The well is allowed to flow-back (i.e., the fluids
inside the well flow toward the surface) after the fracturing
operation. The flow-back is stopped (usually by using pumps at the
surface) and then the fluid is flown into the well. This pattern of
flowing the fluid in one direction, stopping the flow, and the
flowing the fluid in the opposite direction can be identified by
the controller 412 by using the velocity sensor 456. In one
application, the pattern includes flowing 5 barrels back (i.e., out
of the well), waiting for 2 minutes, and then pumping 5 barrels
back into the well. Other quantities and times may be used. When
this "finished pattern" is identified, the controller 412 knows
that the fracturing process is finished and needs to close the
sleeve.
[0046] The controller 412 connects another valve 406 to the
hydraulic pressure in the accumulator so that the second piston 438
moves in the opposite direction relative to the configuration shown
in FIG. 10. FIG. 11 shows the second piston 438 taking the sleeve
dogs 430 and the sleeve 210 back to the closed position as in FIG.
9. Note that during the opening and the closing of the sleeve, the
holding dogs 420 and the seal 440 do not move along the
longitudinal axis X or along the radial axis R.
[0047] After the sleeve 210 has been closed, it is time to move the
setting tool to the next casing. To achieve this objective, the
holding dogs 420 and the sleeve dogs 430 are disengaged in step 812
(or closed, i.e., retracted along the radial axis R toward the
center axis of the setting tool), as illustrated in FIG. 12. The
dogs are disengaged from their connections with the corresponding
grooves in the casing by moving the sleeve ramps 432 with the
piston 434 and the holding ramps 422 with the piston 424. In this
regard, note that FIG. 12 shows the bottom regions 420B and 430B of
the holding dogs 420 and the sleeve dogs 430, respectively, to be
at the bottom of their respective ramps. FIG. 12 also shows the top
regions 420A and 430A of the holding dogs 420 and the sleeve dogs
430, respectively, disengaged from the corresponding grooves 224
and 226. The controller 412 can be programmed to perform these
operations sequentially, with a given wait time between two
subsequent operations.
[0048] In step 814, the operator pumps the setting tool 400
downward toward the next casing. The setting tool monitors its
movement with its velocity sensor 456 (e.g., the velocity sensor
may include one or more accelerometers). After a given distance D,
which is calculated to be less than a distance from the openings
212 of one casing to the openings of an adjacent casing, the
controller 412 is configured to open the holding dogs (i.e., to
move the corresponding rams) so that the holding dogs catch and
engage the holding groove of the next casing. This means that the
process disclosed in FIG. 8 returns to step 802 and performs all
the steps discussed above for the next casing. This process
continues until each casing has been opened, fractured and then
closed. At the end of this process, all the stages have been
fractured and all the valves are closed. As previously discussed,
the operator may select to not open each casing.
[0049] The setting tool needs now to be retrieved to the surface.
For this action, a retrieval tool is sent in the well. The
retrieval tool is configured to latch onto the fishing neck 452 of
the setting tool 400. The retrieval tool may be attached to the
wireline (or another line, e.g., slickline) to be lowered into the
well. Once the retrieval tool latches on the fishing neck 452, the
wireline is pulled up to bring to the surface the setting tool. The
controller 412 of the setting tool, based on measurements received
from the velocity sensor, determines that the setting tool is
moving toward the surface and can instruct the valves 406 to
actuate the corresponding pistons to make sure that the dogs sit at
the bottom of the corresponding ramps, so that neither the holding
dogs nor the sleeve dogs engage a corresponding groove in the
interior wall of the casings.
[0050] In one embodiment, as shown in FIG. 13, is it noted that
sleeve dogs 430 have the top portion 430A moving up and down along
the radial direction R as previously discussed. The top portion
430A is biased by a spring 436. However, when the corresponding
ramp 432 is moved under the base portion 430B, top portion 430A
moves in tandem with the base portion 430B upwards. A protection
region 1300 is formed around the top portion 430A. The protection
region 1300 is designed to not engage any groove in the interior
wall of the casing when the setting tool moves through the setting
tool. FIG. 13 shows that the top region 430A fits inside the
protection region 1300 when the ramp 432 is not pushing radially
the base portion 430B. The same structure may be employed for the
holding dogs 420. Holding dogs 420 may have plural springs 426. In
one application, the holding dogs and/or the sleeve dogs have
multiple elements that "bite" into the corresponding groove formed
in the interior wall of the casing. The figures discussed until now
show a holding or sleeve dog at the top the figure and one at the
bottom. Those skilled in the art would understand that other
elements similar to those shown in the figures may be added all
around the longitudinal axis X of the setting tool to better engage
the casing and/or the sleeve.
[0051] In one embodiment, the setting tool may be used to open the
sleeve of each casing valve while the setting tool moves from the
bottom of the well toward the top so that well production can
commence. For this situation, the holding dogs are open, i.e., the
corresponding ramp is moved under the dogs to push them outward
along the radial direction. The setting tool is moved upward with
the wireline until the holding dogs engage a corresponding groove
in a casing. The velocity sensors of the setting tool determine
that the setting tool has stopped. The controller of the setting
tool then instructs the sleeve dogs to engage the sleeve groove of
the casing and open the sleeve. The casing sleeve is opened. Then
all the dogs are disengaged and the setting tool can move upwards
towards the next casing.
[0052] In one embodiment, it is possible that the setting tool gets
stuck in a casing. In this situation, as shown in FIG. 14, the
wireline or slickline is pulled with an increased force to shear
pins 470, which make the ramps 422 and 432 to move away from the
base portions of the dogs, so that the dogs move toward the central
part of the setting tool under their bias generated by the springs
426 and 436, and thus, the setting tool is free to move inside the
casing. The wireline is then used to pull the setting tool out of
the casing string. FIG. 14 also shows possible accumulators 480,
482 and 484 for storing the hydraulic energy. In one application,
chambers 482 and 484 are used for moving the pistons discussed
above along a desired direction.
[0053] A method for opening a sleeve of a casing and then
fracturing a stage associated with the casing is now discussed with
regard to FIG. 15. The method includes a step 1500 of lowering a
setting tool 400 inside a casing 200 having plural openings 212
covered by a sleeve 210, a step 1502 of engaging a set of holding
dogs 420 of the setting tool 400 with a corresponding holding
groove 224 formed inside the casing 200, a step 1504 of engaging a
set of sleeve dogs 430 of the setting tool 400 with a corresponding
sleeve groove 226 formed in the sleeve 210, and a step 1506 of
opening the sleeve 210 by translating the sleeve dogs 430 along a
central longitudinal axis X, relative to the holding dogs 420. The
method may further include one or more of the step of fracturing a
formation around the casing by pumping a fluid into the casing, the
step of closing the sleeve by translating back the sleeve dogs
along the central longitudinal axis X, relative to the holding
dogs, the step of disengaging the holding dogs and the sleeve dogs
from their respective grooves, and the step of pumping the setting
tool further down the well to the next casing. In one application,
the step of opening includes a step of activating a sleeve piston
for translating the sleeve dogs along the central longitudinal
axis, a step of releasing from an accumulator a fluid under
pressure for activating the sleeve piston and/or a step of
recharging the accumulator by pumping the fluid into the well with
a pump at a surface of the well.
[0054] Another method for fracturing a well, with the setting tool
discussed in the previous embodiments, is now discussed with regard
to FIGS. 16A to 16C. The method includes a step 1600 of providing
multiple casing valves in a casing string, the casing string having
a toe valve at the bottom. The casing valves do not need to have
burst discs or any type of time delay, but each casing has latching
profiles and a sliding sleeve as illustrated in the previous
figures.
[0055] In step 1602, the wiper plug is pumped down. When the wiper
plug bottoms-out, the operator of the well will note a pressure
spike at the surface. Then, in step 1604, the well is pressured up
to test the casing string. If the pressure holds, then the operator
applies more pressure to rupture the burst disk in the toe valve.
At this time, the openings in the toe valve are opened and in step
1606, the stage associated with the toe valve is fractured. After
the fracturing of this stage is completed, the well may be
cleaned.
[0056] In step 1608, the setting tool 400 is inserted into the well
and pumped down. Because the setting tool is moving only in water,
there is less chance of getting stuck in the casing. The setting
tool has a pressure transducer and a fluid velocity sensor at least
at the top of the body. The setting tool has holding dogs that are
spring-loaded open. However, they default to closed if there is a
loss of power. The setting tool has a spring-loaded accumulator 480
with enough hydraulic energy to open and close several casing valve
sleeves. The setting tool may use solenoid valves 406 to reduce the
electrical energy required to activate the dogs. The accumulator
480 stores fluid under pressure and is configured to actuate a
holding piston, a first sleeve piston and a second sleeve piston
for moving the set of holding dogs and the set of sleeve dogs. In
one application, the holding piston, the first sleeve piston and
the second sleeve piston are concentric to each other.
[0057] The spring-loaded holding dogs latch in step 1610 into a
profile (e.g., holding groove) in the first casing valve near its
heel and holds the setting tool in position with its seal 440 under
the casing valve. The well is now plugged and the operator of the
well notices a pressure spike at this point.
[0058] In step 1612, the setting tool knows it stopped (because of
the measurement received from the velocity sensor and/or pressure
transducer) and is in position. In step 1614, the operator
increases the casing's pressure to re-charge the hydraulics (e.g.,
accumulator 480) in the setting tool 400. In step 1616, the setting
tool uses its stored energy to open the sleeve dogs and to open the
casing valve's sleeve. Once the sleeve is open, the upper-most
stage is fractured in step 1618. In step 1620, if the well sands
out, the operator can cycle the flow to clear it up, because the
setting tool is held below the flow, and not in the sand.
[0059] After finishing the fracturing operation, the operator sends
in step 1622 a stop and start fluid flow pattern so that the
setting tool recognizes as the "Finished Frac-ing Pattern" signal
indicating that the fracturing operation has been concluded (if no
signal is received, it times out based on a timer started by the
controller 412). The setting tool closes in step 1624 the casing
valve's sleeve, the setting tool's sleeve dogs, and then closes the
setting tool's holding dogs. In step 1626, the operator pumps the
setting tool to the next casing valve, still moving in water only.
Next, the setting tool spring-opens the holding dogs and latch onto
the next casing valve (i.e., repeats step 1610), and seals. The
process repeats now the steps 1612 to 1626 of holding in position
with the seal, pressurizing the casing to charge the setting tool,
opening the sleeve, fracturing the current stage, closing the
sleeve, closing the holding dogs, moving the setting tool to the
next casing valve, spring-opening the holding dogs, latching to the
next casing valve and so on.
[0060] When this process is completed, all of the stages are
fractured and their sleeves are re-closed. The retrieval tool is
pumped down in step 1628, on a Slickline, or a Wireline and latched
onto the setting tool. The setting tool would be chased down to the
toe valve. However, the fluid flow is allowed to go around the
setting tool. The setting tool's holding dogs are still sprung
open. The setting tool is pulled up the casing spring in step 1628
until the holding dogs latch to the lowermost casing valve. The
well is again plugged. In step 1630, the operator pressures the
well to charge the accumulator of the setting tool. In step 1632,
the setting tool opens the casing valve's sleeve so that oil and/or
gas from the formation can enter the casing. In step 1634 the
setting tool closes its holding dogs and the setting tool is pulled
up in step 1636 toward the next casing valve and the previous steps
are repeated to open the next sleeve. In this way all the sleeves
are open and the exploration of the well can commence as the oil
and/or gas is now flowing through the openings into the well.
[0061] The method discussed above may be modified as now discussed.
In one embodiment, instead of pumping the retrieval tool to the
bottom of the well to hook it to the setting tool, the setting tool
can be moved up-hole by using the flow-back of each of the stages.
When the setting tool finishes opening the last casing valve, it
closes its holding dogs and then can flow-back the well. The
setting tool moves up toward the next casing valve. As the setting
tool arrives at the next casing valve, the setting tool
spring-opens the dogs and latches onto the next casing valve. Then,
the setting tool opens the sleeve, and the operator pressures up
the formation and the setting tool. Next, the setting tool closes
the holding dogs and flows-back the well so that the setting tool
moves upward. This process continues until the setting tool arrives
at the last casing valve near the heel. After opening the last
sleeve, the setting tool is kept latched to the casing valve and
the retrieval tool is pumped in the vertical section of the well.
After the retrieval tool is connected to the setting tool, the
holding dogs of the setting tool are released from the groove of
the casing, and both tools are retrieved from the well. Those
skilled in the art would be able, having the benefit of this
disclosure, to practice different variations of the methods
discussed herein. Note that while the above embodiments have
discussed using a wireline to convey the setting tool inside the
well (or at least to retrieve the setting tool), it is possible to
have the setting tool move autonomously inside the well, or to be
attached at the end of a slickline or wire rope, or wireline, or
coiled tubing or coiled tubing with wireline inside.
[0062] The setting tool discussed above may have the hydraulics
implemented with solenoids for powering the holding dogs open and
closed, and open and close the casing valve's sleeve. The holding
dogs are configured to "Fail safe" in the closed position. The
controller and sensors may be selected to work with "AA" lithium
batteries. Thus, no high power electrical devices are used except
for the solenoids. In one application, the setting tool would carry
enough batteries for a 100 casing valve stages per run. In another
application, the setting tool could carry enough batteries to
complete the entire job, so that recharging is not required.
[0063] During pressurizing the casing, the upper pressure may move
a piston in the setting tool that has check valves. This "pump"
mechanism re-charges the hydraulic accumulator during every
pressurization cycle.
[0064] "Time Based," "Velocity Pattern Recognition," or "Pressure
Pattern Recognition" signals based communication is possible
between the operator of the well and the controller of the setting
tool. These types of communication are enhanced by the presence of
the pressure transducers, fluid velocity sensor, and accelerometer.
In one application, the setting tool may have an information
storing device (e.g., a memory) for post-job analysis (as an
example, it will know if all the sleeves were opened).
[0065] The setting tool may act as a moving, resettable plug, rated
at 10,000 psi differential pressure, with dogs that open and close
the casing valve's sleeves. In one application, the setting tool
may be designed to have the upper section made of materials that
are acid resistant. The setting tool may be designed for multiple
jobs, with minimal maintenance.
[0066] One or more advantages of the setting tool discussed above
are as follows: [0067] pin point frac-ing performed at each stage;
[0068] no debris in the well due to the seal 440; [0069] no
dissolving balls are needed; [0070] no drilling out of various
plugs between the stages is required; [0071] no waiting for
activation; [0072] need not Frac all of the casing valve stages;
[0073] for an autonomous tool, pre-program the setting tool to skip
some casing valves, or use simple down-link communication (pressure
and fluid velocity); [0074] any of the stages can be fractured with
another future run with the setting tool; [0075] no coiled tubing
frac-ing; [0076] the setting tool could be conveyed on slickline,
wireline, coiled tubing, or drill pipe; [0077] the sleeves can be
individually re-opened or re-closed with future runs; [0078] the
sleeves can be partially opened; [0079] selected sleeve can be open
or closed; [0080] with a setting tool memory, a record is keep of
when each sleeve was moved; [0081] if a wireline is conveyed, the
setting tool can contain a pump to charge its hydraulic system, and
have real time data acquisition of pressure and velocity downhole
while frac-ing; [0082] less water usage than a conventional
fracturing operation; [0083] no explosives are used during the
fracturing; [0084] the casing valves are 11'' shorter and have a
smaller outer diameter (e.g., 6.50'') than current FracBack design;
[0085] the casing valves have no deforming seat, no locking ring,
no collet, no balls, no darts, nor any outer burst disk cover;
[0086] enough batteries can be carried for over a hundred stages;
[0087] the setting tool is reusable while the conventional guns are
not; [0088] the setting tool may include communication capability
while the conventional guns do not; [0089] the same setting tool
may be used for different size casings; [0090] the setting tool may
have the wear items (seals and dogs) easily replaced for multiple
usage; [0091] the parts exposed to corrosion can be made of acid
resistant materials; [0092] the structure of the casing valve being
simple, its price is low; [0093] the setting tool requires less
surface equipment for its usage; [0094] no conveyance equipment in
the casing during Frac-ing; [0095] faster setup that conventional
fracturing operations; [0096] the memory record the pressures;
[0097] depth knowledge; and [0098] can monitor down-hole pressure
in real-time.
[0099] The disclosed embodiments provide methods and systems for
selectively actuating one or more casing valves in a casing string.
It should be understood that this description is not intended to
limit the invention. On the contrary, the exemplary embodiments are
intended to cover alternatives, modifications and equivalents,
which are included in the spirit and scope of the invention as
defined by the appended claims. Further, in the detailed
description of the exemplary embodiments, numerous specific details
are set forth in order to provide a comprehensive understanding of
the claimed invention. However, one skilled in the art would
understand that various embodiments may be practiced without such
specific details.
[0100] Although the features and elements of the present exemplary
embodiments are described in the embodiments in particular
combinations, each feature or element can be used alone without the
other features and elements of the embodiments or in various
combinations with or without other features and elements disclosed
herein.
[0101] This written description uses examples of the subject matter
disclosed to enable any person skilled in the art to practice the
same, including making and using any devices or systems and
performing any incorporated methods. The patentable scope of the
subject matter is defined by the claims, and may include other
examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims.
* * * * *