U.S. patent application number 11/430634 was filed with the patent office on 2007-11-15 for window casing.
This patent application is currently assigned to Halliburton Energy Services, Inc.. Invention is credited to Jim B. Surjaatmadja.
Application Number | 20070261851 11/430634 |
Document ID | / |
Family ID | 38282994 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070261851 |
Kind Code |
A1 |
Surjaatmadja; Jim B. |
November 15, 2007 |
Window casing
Abstract
A system and method for perforating and fracturing at least one
of a casing or a sleeve proximate to the casing in a wellbore are
perforated to form one or more apertures therein. The apertures are
operable to allow passage of fluids between an interior of the
casing and earth surrounding the wellbore. The earth surrounding
the wellbore can be fractured through the apertures. The sleeve can
be moved to selectively close one or more of the apertures and
substantially seal against passage of fluids therethrough.
Inventors: |
Surjaatmadja; Jim B.;
(Duncan, OK) |
Correspondence
Address: |
JOHN W. WUSTENBERG
P.O. BOX 1431
DUNCAN
OK
73536
US
|
Assignee: |
Halliburton Energy Services,
Inc.
|
Family ID: |
38282994 |
Appl. No.: |
11/430634 |
Filed: |
May 9, 2006 |
Current U.S.
Class: |
166/297 ;
166/308.1; 166/55 |
Current CPC
Class: |
E21B 43/26 20130101;
E21B 23/006 20130101; E21B 43/114 20130101; E21B 34/14
20130101 |
Class at
Publication: |
166/297 ;
166/308.1; 166/055 |
International
Class: |
E21B 43/11 20060101
E21B043/11; E21B 29/00 20060101 E21B029/00 |
Claims
1. A method of treating a wellbore, comprising: perforating at
least one of a casing or a sleeve proximate to the casing in a
wellbore to form one or more apertures therein, wherein the
apertures are operable to allow passage of fluids between an
interior of the casing and earth surrounding the wellbore; and
moving the sleeve to close one or more of the apertures and
substantially seal against passage of fluids therethrough.
2. The method of claim 1 wherein the casing comprises one or more
apertures formed prior to the perforating operation.
3. The method of claim 2 wherein moving the sleeve to close one or
more of the apertures comprises moving the sleeve to close one or
more of the apertures formed prior to the perforating
operation.
4. The method of claim 1 further comprising fracturing a formation
surrounding the wellbore through one or more of the apertures prior
to moving the sleeve.
5. The method of claim 4 wherein fracturing the formation comprises
flowing a fracturing fluid to a location proximate the one or more
apertures though an interior of a working string.
6. The method of claim 4 wherein fracturing the formation comprises
flowing a fracturing fluid to a location proximate one or more
apertures through an annulus between a working string and the wall
of the wellbore.
7. The method of claim 1 wherein perforating the wall of the
wellbore comprises directing fluid at the wall of the wellbore to
form one or more apertures therein.
8. The method of claim 7 further comprising directing fluid through
the one or more apertures into a formation surrounding the wellbore
to fracture the formation.
9. The method of claim 1 wherein perforating at least one of the
casing or the sleeve comprises perforating the casing without
perforating the sleeve.
10. The method of claim 1 wherein: perforating comprises
perforating at least one of the casing or a first sleeve at a first
location; the method further comprises perforating at least one of
the casing or a second sleeve at a second location axially spaced
from the first location to form one or more apertures therein,
wherein the apertures are operable to allow passage of fluids
between an interior of the casing and earth surrounding the
wellbore; and moving the sleeve to close one or more of the
apertures and substantially seal against passage of fluids
therethrough comprises moving at least one of the first sleeve or
the second sleeve to close one or more of the apertures and
substantially seal against passage of fluids therethrough.
11. The method of claim 10 further comprising moving at least one
of the first sleeve or the second sleeve to allow passage of fluids
between the interior of the casing and the earth surrounding the
wellbore.
12. The method of claim 10 further comprising leaving the second
sleeve positioned to allow passage of fluids between the interior
of the casing and the earth surrounding the wellbore.
13. A method of treating a wellbore, comprising: forming one or
more perforations through a casing in the wellbore; flowing fluid
through one or more of the perforations to fracture a formation
about the wellbore; and closing at least one of the perforations to
substantially seal against passage of fluids therethrough.
14. The method of claim 13 wherein forming one or more perforations
through the casing comprises: positioning a downhole tool in the
wellbore; and flowing fluid out of an aperture of the downhole
tool, wherein the aperture is adapted to direct the fluid at the
casing.
15. The method of claim 14 wherein flowing fluid through one or
more of the perforations to fracture the formation further
comprises flowing fluid out of an aperture of the downhole tool to
draw fracturing fluid proximate the downhole tool through one or
more of the perforations and into the formation.
16. The method of claim 15 wherein forming one or more perforations
and fracturing the formation are performed without substantially
longitudinally re-positioning the downhole tool in the
wellbore.
17. The method of claim 13 wherein closing at least one of the
perforations comprises moving a sleeve to cover the at least one
perforation.
18. The method of claim 13 further comprising: forming one or more
perforations through the casing in the wellbore at a second
location longitudinally spaced from the first mentioned location;
and flowing fluid through one or more of the perforations at the
second location to fracture the formation about the wellbore.
19. A well completion system, comprising: a casing adapted for
insertion into the well; a downhole tool adapted for insertion into
the casing and operable to form one or more perforations through
the casing, wherein the one or more perforations are adapted to
allow passage of fluid through the casing; and a sleeve carried by
the casing and movable to cover and substantially prevent passage
of fluid through one or more of the perforations.
20. The well completion system of claim 19 wherein the downhole
tool is adapted to direct fluid through one or more of the
perforations to draw fracturing fluid proximate the downhole tool
through one or more of the perforations and into the formation to
fracture the formation.
21. The well completion system of claim 19 wherein the downhole
tool is adapted to move the sleeve to cover and substantially
prevent passage of fluid through one or more of the perforations.
Description
[0001] This disclosure relates to selectively accessing formations
surrounding wellbores.
[0002] After a wellbore is drilled, the wellbore is often treated
by perforating and fracturing to increase the flow of fluids from
the formation into the wellbore. Perforating entails forming holes
in the walls of the wellbore, for example the casing, to enable the
formation around the wellbore to be fractured. Fracturing entails
inducing fractures in the formation surrounding the wellbore.
[0003] Perforating is generally performed with a perforating tool
that is lowered into the wellbore on a wireline or a coiled or
jointed tubing string. There are a number methods by which to
perforate a wellbore. One method includes utilizing a jetting-type
perforating tool through which a fluid passes at a pressure high
enough to cut openings, or perforate the wall of a wellbore.
Another method includes utilizing a shaped charge-type perforating
tool that uses a directional explosive effect to generate a high
pressure, high velocity jet that creates an opening or a
perforation in the wall of a wellbore. Yet another method includes
utilizing a projectile-type perforating tool that fires a bullet or
projectile into the wall of the wellbore to create an opening or a
perforation therein.
[0004] Fracturing is generally performed by sealing an interval
within the wellbore, for example between two packers on a working
string or between a bridge plug and a seal, such as a packer or a
BOP, at the surface, and pressurizing the wellbore within the
sealed interval to induce fractures in the formation surrounding
the formation. The perforations allow the pressurized fracturing
fluid to enter the formation.
[0005] Once the casing has been fractured, however, there is a
direct communication between the fracture and the wellbore. Should
this fracture produce sand, as is common with most less
consolidated formations, the sand will be produced through the
perforations to the surface, and may abrade or otherwise damage
surface equipment.
SUMMARY
[0006] The present disclosure is directed to systems and methods
for selectively accessing formations surrounding wellbores. Certain
aspects enable closure of perforations in a casing of the wellbore
before and after fracturing has been performed.
[0007] One aspect encompasses a method. In the method at least one
of a casing or a sleeve proximate to the casing in a wellbore are
perforated to form one or more apertures therein. The apertures are
operable to allow passage of fluids between an interior of the
casing and earth surrounding the wellbore. The sleeve is moved to
close one or more of the apertures and substantially seal against
passage of fluids therethrough.
[0008] Another aspect encompasses method of perforating and
fracturing a well. In the method one or more perforations are
formed through a casing of the well. Fluid is flowed through one or
more of the perforations to fracture a formation about the well. At
least one of the perforations are closed to substantially seal
against passage of fluids therethrough.
[0009] Yet another aspect encompasses a well completion system. The
system includes a casing adapted for insertion into the well. A
downhole tool is adapted for insertion into the casing and operable
to form one or more perforations through the casing. The one or
more perforations are adapted to allow passage of fluid through the
casing. A sleeve is carried by the casing and movable to cover and
substantially prevent passage of fluid through one or more of the
perforations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic cross-sectional view of an
illustrative well constructed according to the concepts described
herein.
[0011] FIGS. 2A-2D are schematic cross-sectional views of an
illustrative window casing system according to the concepts
described herein. FIG. 2A depicts the illustrative window casing in
a closed position prior to perforating and fracturing. FIG. 2B
depicts the illustrative window casing in an open position and
receiving an illustrative working string to perforate the window
casing. FIG. 2C depicts the window casing in an open position
during fracturing. FIG. 2D depicts the window casing and a closed
position after perforating and fracturing.
[0012] FIG. 3 is schematic cross-sectional view of the illustrative
window casing receiving an alternate illustrative working string
according to the concepts described herein.
[0013] FIG. 4 is a schematic cylindrical projection of an
illustrative cam slot according to the concepts described
herein.
[0014] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0015] Referring first to FIG. 1, an illustrative well system 10
constructed in accordance with the concepts described herein
includes a wellbore 12 coupled to the surface 14 and extending down
through the earth 16. The wellbore 12 may extend substantially
vertically away from the surface, as is depicted in FIG. 1, or may
deviate to extend at any angle from the surface 14. In some
instances, for example, the entire wellbore 12 or portions thereof
may be slanted, horizontal, and/or curved. The wellbore 12 extends
through one or more (three shown) intervals of interest 18. The
intervals of interest 18 are intervals of the earth 16 in which it
is desired to produce fluids, inject fluids, or perform other
operations. An interval of interest 18 may correspond to a single
formation in the earth 16, may span multiple formations, or may
encompass only a portion of a formation.
[0016] A casing 22 extends through at least portion of the wellbore
12. The casing 22 includes one or more longitudinally spaced window
casings 24. A window casing 24 is a section of casing configured to
enable selective access to the earth 16 surrounding the wellbore
12. One or more window casings 24 may be provided in each of the
intervals of interest 18.
[0017] Although there are numerous configurations of window casing
24 that can be used according to the concepts described herein, an
illustrative window casing 200 is depicted in FIGS. 2A-2D.
Referring specifically to FIG. 2A, illustrative window casing 200
includes a substantially cylindrical outer casing 210 that receives
a moveable sleeve member 212. The outer casing 210 can define a
recess 214 in which the sleeve member 212 resides. In the
illustrative window casing 200, the recess 214 is configured to
allow the sleeve member 212 to slide axially relative to the outer
casing 210. In other instances, the sleeve member 212 can
alternately, or in combination with sliding axially, be configured
to rotate within the outer casing 210.
[0018] Referring now to FIGS. 2A and 2B, the sleeve member 212 is
provided with one or more apertures 216. Some or all of the
apertures 216 can be formed prior to placement of the illustrative
window casing 200 in the wellbore 12, and the remainder or all of
the apertures 216 can be formed after placing the illustrative
window casing 200 in the wellbore 12 (discussed in more detail
below). Likewise, the outer casing 210 is provided with one or more
apertures 218, formed prior to and/or after placement of the
illustrative window casing 200 in the wellbore 12. When the
apertures 218 of the sleeve member 212 at least partially overlap
the apertures 218 of the outer casing 210, the fluid may pass
through the illustrative window casing 200, and more specifically,
between the interior of the sleeve member 212 and the earth 16.
[0019] The sleeve member 212 is movable between an open position
and a closed position. The open position corresponds to the
position of the sleeve member 212 that allows passage of fluid
through the illustrative window casing 200, and the closed position
corresponds to the position of the sleeve member 212 that
substantially seals against passage of fluid through the
illustrative window casing 200. FIGS. 2B and 2C depict the sleeve
member 212 in the open position, shifted to abut the upper end of
the recess 214. In the open position, apertures 216 and apertures
218 at least partially overlap. FIGS. 2A and 2D depict the sleeve
member 212 in the closed position, shifted to about the lower end
of the recess 214. In the closed position, apertures 216 and
apertures 218 do not overlap. Additionally, a plurality of seal
members 220 substantially seal against passage of fluid between the
apertures 216 and 218. In the illustrative window casing 200, the
seal members 220 are positioned on the outer surface of the sleeve
member 212 and are configured to substantially seal against passage
of fluid between the sleeve member 212 and the outer casing 210. In
other instances, some or all of the seal members 220 can be
provided on the outer casing 210 itself and configured to
substantially seal against the sleeve member 212.
[0020] The sleeve member 212 is moved between the open and closed
position with a sleeve operating tool. Although there are numerous
configurations of sleeve operating tools that can be used according
to the concepts described herein, an illustrative sleeve operating
tool 222 is depicted in FIGS. 2B-2D (best seen in FIG. 2D). The
illustrative sleeve operating tool 222 is adapted to be coupled to
a working string 224 and lowered through the wellbore 12 into the
interior of the sleeve member 212. The illustrative sleeve
operating tool 222 may also be adapted to couple to or carry other
devices, for example, a tool for forming apertures 216 and/or
apertures 218 such as illustrative hydraulic jet stub 226
(described in more detail below).
[0021] The illustrative sleeve operating tool 222 includes a tool
body 228 that carries one or more outwardly extendable collets 230.
The collets 230 are configured to engage a corresponding profile
232 on the sleeve member 212 when extended outwardly into
engagement with the profile 232, and move the sleeve member 212 as
the illustrative sleeve operating tool 222 is itself moved. In one
instance, the collets 230 are inwardly biased and driven outward as
they bear against a wedge surface 234 on the tool body 228. When
not outwardly extended (i.e. retracted), the collets 230 are
positioned to lightly engage and easily release the profile 232
without substantially moving the sleeve member 212. The
illustrative sleeve operating tool 222 includes two axially spaced
sets of collets 230 coupled to a carrier 236. The carrier 236 is
received over the tool body 228 and configured to both slide
axially and rotate on the tool body 228. The tool body 228 also
includes two axially spaced wedge surfaces 234. Each wedge surface
234 is oriented to slope outward and away from the other wedge
surface, so that when the carrier 236 is shifted towards one or the
other wedge surface 234, the collets 230 that contact the wedge
surface 234 are wedged outward. Because the collets 230 lightly
engage the profile 232 when not outwardly extended, the collets 230
on the leading edge of the carrier 236 pass over the profile 232 as
the illustrative sleeve operating tool 222 is passed through the
sleeve member 212. The collets 230 on the trailing edge of the
carrier 236 will engage the profile 232 and drag the carrier 236
toward the corresponding wedge surface 234. As the illustrative
sleeve operating tool 222 continues into the sleeve member 212, the
wedge surface 234 drives the collets 230 on the trailing edge into
further engagement with the profile 232, and thereafter draws the
sleeve member 212 along with illustrative sleeve operating tool
222.
[0022] Accordingly, to move the sleeve member 212 from the open
position to the closed position, the illustrative sleeve operating
tool 222 is lowered downward through the illustrative window casing
200. The collets 230 on the leading end pass over the profile 232.
The collets 230 on the trailing end lightly engage the profile 232
and draw the carrier 236 toward the trailing wedge surface 234. The
trailing wedge surface 234 wedges the collets 230 into more
positive engagement with the profile 232, and further downward
movement draws the sleeve member 212 along with the illustrative
sleeve operating tool 222 to the closed position. To move the
sleeve member 212 from the closed position to the open position,
the illustrative sleeve operating tool 222 is lowered downward
through the illustrative window casing 200 (if not already below
the illustrative window casing 200) and then withdrawn upward
through the illustrative window casing 200. As above, the collets
230 on the leading end pass over the profile 232. The collets 230
on the trailing end lightly engage the profile 232 and draw the
carrier 236 toward the trailing wedge surface 234. The trailing
wedge surface 234 wedges the collets 230 into more positive
engagement with the profile 232, and further upward movement draws
the sleeve member 212 along with the illustrative sleeve operating
tool 222 to the open position.
[0023] The tool body 228 has one or more cam slots 238 that receive
one or more corresponding pins 240 on the carrier 236. The cam slot
238 and pin 240 control the movement of the carrier 236, and thus
whether the collets 230 can extend, engage and move sleeve member
212. FIG. 4 depicts a cylindrical projection of an illustrative cam
slot 238. The illustrative cam slot 238 has a plurality of
trapezoidal neutral receptacles 242, a closed position receptacle
244, and an open position receptacle 246 (two shown). Additional or
fewer closed position receptacles 244, open position receptacles
246 or neutral receptacles 242 can be provided, for example, to
achieve desired operation of the carrier 236 or accommodate
additional or fewer pins 240. The neutral receptacles 242, closed
position receptacle 244 and open position receptacles 246 are
coupled to one another to allow the pins 240 to traverse between
the receptacles. The closed position receptacle 244 extends axially
outward from the neutral receptacles 242 in one direction, and the
open position receptacles 246 extend axially outward from the
neutral receptacles 242 in an opposite direction. In the
illustrative sleeve operating tool 222, the closed position
receptacle 244 extends upward, and the open position receptacles
246 extend downward.
[0024] With the pin 240 received in any of the neutral receptacles
242, the carrier 236 is retained relative to the tool body 228 so
that the collets 230 cannot engage either wedge surface 234.
Accordingly, the illustrative sleeve operating tool 222 can pass
through the window casing 200 without opening or closing the sleeve
member 212. With the pin 240 received in the closed position
receptacle 244, the carrier 236 can move to wedge the collets 230
on the upper wedge surface 234 into engagement with the profile 232
when the illustrative sleeve operating tool 222 is moved downward
through the sleeve member 212. With the pin 240 received in the
open position receptacle 246, the carrier 236 can move to wedge the
collets 230 on the lower wedge surface 234 into the profile 232 as
the illustrative sleeve operating tool 222 is moved upward through
the sleeve member 212.
[0025] Each time the illustrative sleeve operating tool 222 passes
through the sleeve member 212, the pin 242 moves to an adjacent
receptacle (neutral receptacle 242, open position receptacle 246,
or closed position receptacle 244). Accordingly, the illustrative
sleeve operating tool 222 can be selectively configured to change
the sleeve member 212 to the open position, change the sleeve
member 212 to the closed position or pass through the illustrative
window casing 212 without changing the position of the sleeve
member 212 by alternately passing the sleeve operating tool 222
through the sleeve member 212. For example, if the pin 240 is
received in the first open position receptacle 246 (at the top
right of FIG. 4), the pin 240 can be moved to a neutral receptacle
242 by passing the illustrative sleeve operating tool 222 downward
through the sleeve member 212. As noted above, with the pin 240 in
a neutral receptacle 242, the sleeve operating tool 222 can pass
through the sleeve member 212 without changing its position. By
passing the sleeve operating tool 222 upward and then back downward
through the sleeve member 212, the pin 240 is then moved to the
closed position receptacle 244. As noted above, with the pin 240 in
the closed position receptacle 244, the sleeve operating tool 222
will move the sleeve member 212 to the closed position when it
passes downward through the sleeve member 212. By passing the
sleeve operating tool 222 upward through the sleeve member 212, the
pin 240 is moved to another neutral receptacle 242. By passing the
sleeve operating tool 222 downward and then upward through the
sleeve member 212, the pin 240 can be moved to another open
position receptacle 246. As discussed above, with the pin 240 in an
open position receptacle 246, the sleeve operating tool 222 will
move the sleeve member 212 to the open position when it passes
upward through the sleeve member 212.
[0026] Referring back to FIG. 2B, if at least some of the apertures
216 or apertures 218 are to be formed with the illustrative window
casing 200 in the wellbore 12, the working string 224 includes a
device to form the apertures. In one instance, the device is
hydraulic jet sub 226. In one instance, the hydraulic jet sub 226
is a jet sub similar to that described in U.S. Pat. No. 5,765,642.
In other instances, the device can be a shaped charge, projectile
or other perforating device. The hydraulic jet sub 226 is a device
configured to direct high pressure fluid radially outward to
perforate (i.e. form apertures in) the wall of the wellbore 12,
including casing 22 and illustrative window casing 200. To this
end, the hydraulic jet sub 226 includes a body 248 adapted to
couple to the illustrative sleeve operating tool 222, and the body
248 has one or more radially oriented ports 250 spaced about its
circumference. In one instance, the ports 250 may be nozzles
configured to consolidate and direct flow from the interior of the
hydraulic jet sub 226 into the wall of the wellbore 12. It is
within the scope of the invention to use other types of devices for
forming apertures, in combination with or in lieu of the hydraulic
jet sub 226, to perforate the wall of the wellbore 12, for example,
a projectile perforating gun, shaped charge perforating gun, or
other system.
[0027] As is discussed in more detail below, the hydraulic jet sub
226 is operated to perforate at least one of the outer casing 210
(forming apertures 218) or the sleeve member 212 (forming apertures
216). In certain embodiments, the ports 250 of the hydraulic jet
sub 226 are positioned about the body 248 such that when the
hydraulic jet sub 226 is coupled to the illustrative sleeve
operating tool 222, and the collets 230 on the upper end of the
illustrative sleeve operating tool 222 engage the profile 232 of
the sleeve member 212 in the open position, the hydraulic jet sub
226 forms the apertures 216 and apertures 218 between the seal
members 220.
[0028] With the sleeve member 212 in the open position, the earth
16 surrounding the wellbore 12 may be fractured by introducing high
pressure fracturing fluid into the wellbore 12 to flow through the
apertures 216 and apertures 218 and into the earth 16. The
fracturing fluid can be communicated to the vicinity of the
apertures 216 and apertures 218 in numerous ways. For example, the
fracturing fluid can be communicated to the vicinity of the
apertures 216 and apertures 218 entirely through the annulus
between working string 224 and the wall of the wellbore 12 (e.g.,
casing 22). In other instances, at least a portion of the
fracturing fluid can be communicated to the vicinity of the
apertures 216 and apertures 218 through the interior of the working
string 224. FIG. 2C depicts the fracturing fluid flowing
(represented by arrows 254) through both the working string 224 and
through the annulus between the working string 224 and the wall of
the wellbore 12. In this instance, the fracturing fluid exits the
interior of the working string 224 through ports 250 of the
hydraulic jet sub 226. The flow of fracturing fluid out of ports
250 into the perforations 252 creates a pressure gradient that
draws the fracturing fluid from the annulus between the working
string 224 and the wall of the wellbore 12 into the perforations
252. The combined flow from the annulus and from the hydraulic jet
sub 226 fractures the earth 16 through the apertures 216 and
apertures 218.
[0029] Although, it is within the scope of the invention to direct
all of the fracturing fluid through the working string 224 and out
the ports 250, it is many times difficult to configure the ports
250 to both operate efficiently in perforating the wall of the
wellbore 12 and efficiently communicate the flow rate and withstand
the erosive effects of the volume of fracturing fluid (including
proppant) necessary to fracture the earth 16. FIG. 3 depicts an
alternate configuration in which the working string 224 includes a
fluid distributor 256 changeable from directing flow axially
through the fluid distributor 256 to directing flow both axially
through the fluid distributor 256 and laterally through one or more
side ports 258 in the working string 224. When the fluid
distributor 256 is configured to direct flow axially through the
fluid distributor 256, flow from the interior of the working string
224 is directed to the hydraulic jet sub 226. Therefore, during
perforating operations with the hydraulic jet sub 226, the fluid
distributor 256 can be configured to direct flow axially through
the fluid distributor 256 into the interior of the hydraulic jet
sub 226 and perforating operations performed substantially as
described above. During fracturing operations, the fluid
distributor 256 can be configured to direct flow both axially
through the fluid distributor 256 and laterally through the side
ports 258. At least a portion of the flow of fracturing fluid
through the side ports 258 is directed into the annulus between the
working string 224 and the wall of the wellbore 12. In one
instance, a majority of the fracturing fluid is directed through
the side ports 258. The side ports 258 may be configured to be less
of a flow restriction than the ports 250 of the hydraulic jet sub
226. Further, diverting a portion of the flow through the side
ports 258 reduces the amount of flow through the ports 250 of the
hydraulic jet sub 226.
[0030] An illustrative method of perforating and fracturing a
wellbore according to the sequence of operations depicted in FIGS.
2A-C will now be discussed. In the illustrative method, the working
string 224 including the illustrative sleeve operating tool 222 and
hydraulic jet sub 226 is lowered through the wellbore 12 into the
vicinity of an illustrative window casing 200. Perforating and/or
fracturing operations can be performed at more than one
illustrative window casing 200 during a single trip of the working
string 224 into and out of the wellbore 12. If perforating and/or
fracturing operations are to be performed at multiple illustrative
window casings 200, the working string 224 can be lowered through
the wellbore 12 into the vicinity of the illustrative window casing
200 furthest from the surface 14, perforating and/or fracturing
operations performed at the illustrative window casing 200 as
described herein, the working string 224 drawn up the wellbore 12
to the next illustrative window casing 200 to be perforated and/or
fractured (not all illustrative window casings 200 in a wellbore 12
must be perforated or fractured), and so on. In other words, the
operations can be performed in illustrative window casings 200
sequentially from the bottom of the wellbore 12 up. Alternately,
the operations can be performed in illustrative window casings 200
sequentially from the surface 14 towards the bottom of the wellbore
12, or in any other order or in no specific order.
[0031] In FIG. 2A the illustrative window casing 200 is shown
installed with the sleeve member 212 in the closed position.
However, it is within the scope of the invention to install the
illustrative window casing 200 with the sleeve member 212 in the
open position (the open position shown in FIG. 2B). If the sleeve
member 212 is in the closed position, the illustrative sleeve
operating tool 222 is configured to move the sleeve member 212 to
the open position. To this end, the collets 230 on the lower end of
the carrier 236 reside adjacent the lower wedge surface 234. The
illustrative sleeve operating tool 222 is lowered through the
sleeve member 212 so that the collets 230 on the lower end of the
carrier 236 pass downward past the profile 232 on the sleeve member
212. The illustrative sleeve operating tool 222 is then drawn back
up through the sleeve member 212, so that the collets 230 lightly
engage the profile 232. Further upward movement wedges the collets
203 against the lower wedge surface 234, more positively engages
the collets 230 in the profile 232, and draws the sleeve member 212
to the open position. With the collets 230 on the lower end of the
carrier 236 engaged in the profile 232 and the sleeve member 212 in
the open position, the ports 250 of the hydraulic jet sub 226 are
aligned between the seal members 220.
[0032] Referring to FIG. 2B, the hydraulic jet stub 226 is actuated
to perforate the outer casing 210 and the sleeve member 212, thus
forming one or more apertures 216 and apertures 218. The hydraulic
jet sub 226 is actuated by supplying high pressure fluid down the
interior of the working string 224 and out the ports 250. In some
instances, the perforations 252 can extend into the earth 16.
[0033] The earth 16 surrounding the wellbore 12 may be fractured by
introducing high pressure fracturing fluid into the wellbore 12 to
flow through the apertures 216 and apertures 218 (whether formed by
perforating as described above or provided prior to installation)
and into the earth 16. As discussed above, the fracturing fluid can
be communicated to the vicinity of the apertures 216 and 218 in a
number of ways. FIG. 2C depicts the fracturing fluid flowing
(represented by arrows 254) through both the annulus between the
working string 224 and the wall of the wellbore 12 and through the
working string 224 and out of the ports 250. FIG. 3 depicts the
fracturing fluid flowing through the working string 224, a portion
of the fluid being diverted by the fluid distributor 256 through
side ports 258, and a portion of the fluid flowing axially through
the working string 224 into the hydraulic jet sub 226 and exiting a
ports 250 thereof. The flow of fracturing fluid out of the ports
250 into the earth 16 creates a pressure gradient that draws the
fracturing fluid from the annulus between the working string 224
and the wall of the wellbore 12 into the earth 16. In some
instances, the fractures can be initiated by the fluid exiting from
the jet sub 226 as described in U.S. Pat. No. 5,765,642.
[0034] After the fracturing operations are complete, the working
string 224 can be withdrawn from the wellbore 12 or moved to
another illustrative window casing 200 to perform perforating
and/or fracturing operations on the other illustrative window
casings. If so desired, the sleeve member 212 can be moved to the
closed position prior to withdrawing the working string 224 from
the wellbore 12 or prior to moving to another illustrative window
casing 200. If multiple window casings 200 are provided in the
wellbore 12, desired ones or all of the window casings 200 can be
moved to the closed position prior to withdrawing the working
string 224 from the wellbore 12. Thereafter, a working string 224
including at least the sleeve operating tool 222 can be run into
the wellbore 12 to selectively open and close the window casings
200.
[0035] By selectively opening and closing different sleeve members
212, one or more intervals of interest 18 can be isolated. For
example, to produce from or inject fluids into a given interval of
interest 18 and no others, only those sleeve members 212
corresponding to the interval of interest 18 are set in the open
position. To produce from or inject fluids into multiple intervals
of interest 18, the sleeve members 212 corresponding to the desired
intervals of interest 18 are set in the open position, and the
others are set to the closed position.
[0036] Of note, the operations of the above-described method need
not be performed in the order depicted in FIGS. 2A-D. Also, steps
can be added or omitted. For example, if the apertures 216 and
apertures 218 are provided in the illustrative window casing 200
prior to being installed in the wellbore 12, the perforating
operations can be omitted. In some instances, the fracturing
operations may be omitted.
[0037] Although several illustrative implementations of the
invention have been described in detail above, those skilled in the
art will readily appreciate that many other variations and
modifications are possible without materially departing from the
concepts described herein. Accordingly, other implementations are
intended to fall within the scope of the invention as defined in
the following claims.
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