U.S. patent application number 14/868460 was filed with the patent office on 2016-04-07 for isolation barrier.
The applicant listed for this patent is Meta Downhole Limited. Invention is credited to William Luke McElligott, Peter Wood.
Application Number | 20160097254 14/868460 |
Document ID | / |
Family ID | 51946937 |
Filed Date | 2016-04-07 |
United States Patent
Application |
20160097254 |
Kind Code |
A1 |
Wood; Peter ; et
al. |
April 7, 2016 |
Isolation Barrier
Abstract
Apparatus and method for creating a barrier across an annulus in
a well bore. First and second morphable sleeves are arranged side
by side on a tubular body and sealed thereto to. Adjacent ends of
each sleeve meet at a valve housing having a valve arrangement with
a first position in which fluid flows from the throughbore of the
tubular body to the first and second sleeves and a second position
which prevents the flow of fluid between the throughbore, the first
chamber and the second chamber. At opposing ends of the sleeves
rupturable barrier devices are positioned. The sleeves can be
morphed together and by rupturing the barriers, each side of the
barrier is active to pressure and collapse is prevented regardless
of the pressure differential across the barrier.
Inventors: |
Wood; Peter; (Aberdeen,
GB) ; McElligott; William Luke; (Exeter, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Meta Downhole Limited |
Aberdeen |
|
GB |
|
|
Family ID: |
51946937 |
Appl. No.: |
14/868460 |
Filed: |
September 29, 2015 |
Current U.S.
Class: |
166/387 ;
166/179 |
Current CPC
Class: |
E21B 33/127 20130101;
E21B 34/10 20130101; E21B 33/1208 20130101; E21B 33/1212 20130101;
E21B 34/063 20130101; E21B 23/06 20130101; E21B 33/1277 20130101;
E21B 33/1243 20130101 |
International
Class: |
E21B 33/127 20060101
E21B033/127; E21B 34/06 20060101 E21B034/06 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2014 |
GB |
GB1417671.3 |
Claims
1. An isolation barrier, comprising: a tubular body having a
throughbore, the tubular body arranged to be run in and secured
within a larger diameter generally cylindrical structure; a valve
housing located on the exterior of the tubular body; a first sleeve
member positioned on the exterior of the tubular body with a first
end being sealed thereto and a second end being sealed to the valve
housing to create a first chamber within the first sleeve; a second
sleeve member positioned on the exterior of the tubular body with a
first end being sealed thereto and a second end being sealed to the
valve housing to create a second chamber within the second sleeve;
first and second rupturable barrier devices located at the first
ends of the first and second sleeves, respectively; and a valve
arrangement located in the valve housing, the valve arrangement
having a first position in which fluid flows from the throughbore
to the first and second chambers and a second position which
prevents the flow of fluid between the throughbore, the first
chamber and the second chamber.
2. An isolation barrier according to claim 1 wherein the large
diameter structure is selected from a group comprising: an open
hole borehole, a borehole lined with a casing, a borehole lined
with a liner string, or a pipeline within which another smaller
diameter tubular section requires to be secured or centralised.
3. An isolation barrier according to claim 1 wherein the tubular
body is located coaxially within the first and second sleeves.
4. An isolation barrier according to claim 3 wherein the tubular
body is part of a tubular string.
5. An isolation barrier according to claim 1 wherein the valve
arrangement has three branches, a first branch being open to the
throughbore, a second branch connecting to the first sleeve member
and a third branch connecting to the second sleeve member.
6. An isolation barrier according to claim 5 wherein there is a
one-way check valve in the second branch and a one-way valve in the
third branch.
7. An isolation barrier according to claim 1 wherein the
ruptureable barrier devices are rupture disks.
8. An isolation barrier according to claim 1 wherein the
ruptureable barrier devices are set to rupture at pressures around
the morphed pressure value so that the sleeves are morphed prior to
rupture of the barrier devices.
9. An isolation barrier according to claim 5 wherein the first
branch of the valve arrangement includes a ruptureable barrier
device.
10. A method of setting an isolation barrier in a well bore,
comprising the steps: (a) locating first and second sleeve members
side-by-side on the exterior of a tubular body and sealing them
thereto to create first and second chambers therebetween; (b)
running the tubular body on a tubular member into a wellbore and
positioning the sleeve members at a desired location within a
larger diameter structure; (c) pumping fluid through the tubular
member and increasing the fluid pressure to provide fluid at a
morphed pressure value at the sleeve members; (d) simultaneously
pumping fluid at the morphed pressure value into the chambers
causing the sleeves to move radially outwardly and morph against an
inner surface of the larger diameter structure; (f) once morphed,
preventing fluid from passing between the tubular member and the
chambers, and between the chambers; and (g) creating an opening at
a first end of the first sleeve member and at a second end of the
second sleeve member.
11. A method of setting an isolation barrier in a well bore
according to claim 10 wherein the large diameter structure is
selected from a group comprising: an open hole borehole, a borehole
lined with a casing, a borehole lined with a liner string, or a
pipeline within which another smaller diameter tubular section
requires to be secured or centralised.
12. A method of setting an isolation barrier in a well bore
according to claim 10 wherein step (d) includes the step of pumping
fluid through a valve arrangement between the sleeves.
13. A method of setting an isolation barrier in a well bore
according to claim 12 wherein the step (d) includes pumping fluid
through two one way check valves, each arranged at an input to each
sleeve, respectively.
14. A method of setting an isolation barrier in a well bore
according to claim 10 wherein the method includes the step of
rupturing a disc at the valve arrangement to allow fluid to enter
the chambers when the pressure reaches a desired value.
15. A method of setting an isolation barrier in a well bore
according to claim 10 wherein method includes the steps of running
in a hydraulic fluid delivery tool, creating a temporary seal above
and below the valve arrangement and injecting fluid from the tool
into the chambers via the valve arrangement.
Description
[0001] The present invention relates to an apparatus and method for
securing a tubular within another tubular or borehole, and creating
a seal across an annulus in a well bore. In particular, though not
exclusively, the invention relates to morphing dual sleeves on a
tubular to form an isolation barrier which is resistive to
collapse.
[0002] In the exploration and production of oil and gas wells,
packers are typically used to isolate one section of a downhole
annulus from another section of the downhole annulus. The annulus
may be between tubular members, such as a liner, mandrel,
production tubing and casing or between a tubular member, typically
casing, and the wall of an open borehole. These packers are carried
into the well on tubing and at the desired location, elastomeric
seals are urged radially outwards or elastomeric bladders are
inflated to cross the annulus and create a seal with the outer
generally cylindrical structure i.e. another tubular member or the
borehole wall. These elastomers have disadvantages, particularly
when chemical injection techniques are used.
[0003] As a result, metal seals have been developed, where a
tubular metal member is run in the well and at the desired
location, an expander tool is run through the member. The expander
tool typically has a forward cone with a body whose diameter is
sized to the generally cylindrical structure so that the metal
member is expanded to contact and seal against the cylindrical
structure. These so-called expanded sleeves have an internal
surface which, when expanded, is cylindrical and matches the
profile of the expander tool. These sleeves work well in creating
seals between tubular members but can have problems in sealing
against the irregular surface of an open borehole.
[0004] The present applicants have developed a technology where a
metal sleeve is forced radially outwardly by the use of fluid
pressure acting directly on the sleeve. Sufficient hydraulic fluid
pressure is applied to move the sleeve outwards and cause the
sleeve to morph itself onto the generally cylindrical structure.
The sleeve undergoes plastic deformation and, if morphed to a
cylindrical metal structure, the metal structure will undergo
elastic deformation to expand by a small percentage as contact is
made. When the pressure is released the metal structure returns to
its original dimensions and will create a seal against the
plastically deformed sleeve. During the morphing process, the inner
surface of the sleeve will take up the shape of the surface of the
wall of the cylindrical structure. This morphed isolation barrier
is therefore ideally suited for creating a seal against an
irregular borehole wall.
[0005] Such a morphed isolation barrier is disclosed in U.S. Pat.
No. 7,306,033, which is incorporated herein by reference. An
application of the morphed isolation barrier for FRAC operations is
disclosed in US2012/0125619, which is incorporated herein by
reference. Typically, the sleeve is mounted around a supporting
tubular body, being fixed at each end of the sleeve to create a
chamber between the inner surface of the sleeve and the outer
surface of the body. A port is arranged through the body so that
fluid can be pumped into the chamber from the throughbore of the
body.
[0006] In use, the pressure of fluid in the throughbore is
increased sufficiently to enter the chamber and force the sleeve
outwardly to morph to the generally cylindrical structure.
Sufficient pressure has been applied when there is no return of
fluid up the annulus which verifies that a seal has been achieved.
Though the sleeve has been plastically deformed and will therefore
hold its new shape, if a sufficient pressure differential is
created across the sleeve wall, there is a possibility that
fracture can occur and the seal may be lost.
[0007] In one application, the pressure of fluid in the throughbore
is maintained to keep a high pressure in the chamber. Indeed most
sleeves are set by applying maximum pressure to the sleeve.
Unfortunately, there is a risk that the pressure could be high
enough to rupture the sleeve. Additionally, if the pressure
differential acts in the opposite direction by a pressure drop in
the throughbore or by an increase in fluid pressure in the annulus
below the sleeve, the sleeve can be forced away from the
cylindrical structure, causing loss of the seal.
[0008] To overcome this, a check valve is used in the port. This
check valve is arranged to stop fluid returning to the throughbore.
Application of sufficient fluid pressure will cause fluid to enter
the chamber through the valve and the sleeve morphs to the
cylindrical structure. When the seal is achieved, the pressure can
be bled off to leave a trapped pressure within the chamber. This
allows an isolation barrier to be created which does not need a
constant fluid supply to maintain it in the sealed position.
[0009] A disadvantage of this system is in that it cannot
compensate for pressure differentials across the sleeve. Pressure
inside the sleeve will be fixed at a morph pressure and there will
be a pressure within the wellbore annulus above and below the
sleeve. This upper and lower annulus pressure may be different and
if a sufficient pressure differential exists across the sleeve, the
sleeve could collapse causing loss of the seal and the isolation
barrier.
[0010] As described in US2012/0125619 for fracing, if a check valve
is provided within the port, then at least one burst disk is also
provided in a port formed all the way through the side wall of the
sleeve or through the sidewall of the seal carrier, but is
importantly only provided at the end of the sleeve that will be
closest to the perforated section of the casing and therefore, will
be closest to the end of the sleeve that will see the high pressure
of the frac fluid when it is pumped. The burst disk will be
arranged to burst and therefore let fluid within the chamber to
flow into the annulus in the location of the formation to be frac'd
in order to protect the rest of the sleeve, in situations where
there is a pre-determined pressure differential across it. In other
words, the burst disk can be intentionally sacrificed in order to
protect the rest of the sleeve when a certain pressure differential
is experienced-say 5,000 psi. Alternatively, and more importantly
the burst disk can be intentionally burst to allow the high
pressure fluid from the high pressure zone of the annulus into
chamber to reinforce the sleeve. This arrangement will likely be
used in situations where the isolation barrier must have a
substantially higher performance in collapse. In operation, the
sleeve will be inflated by for instance an expansion tool such that
fluid is pumped through the check valve to inflate the sleeve.
However, when the final morph fluid pressure is achieved (say
10,000 psi) the rupture disk is arranged to burst such that fluid
can then communicate between the high pressure zone of the annulus
and the chamber. After the disk has burst, this therefore means
that there is zero differential pressure across the sleeve between
the high pressure zone and the chamber and therefore allows the
isolation barrier to be maintained as long as the rupture disk is
on the high pressure side.
[0011] This arrangement has a number of disadvantages: in having to
ensure that the isolation barrier is deployed in the correct
orientation with the rupture disk arranged on the high pressure
side; ensuring that pressure on the `low` pressure side does not
increase to be greater than that on the high pressure side; and
only being able to morph a single sleeve at a time between the
zones.
[0012] It is therefore an object of at least one embodiment of the
present invention to provide a morphed isolation barrier which
obviates or mitigates one or more disadvantages of the prior
art.
[0013] It is a further object of at least one embodiment of the
present invention to provide a method of creating an isolation
barrier in a well bore which obviates or mitigates one or more
disadvantages of the prior art.
[0014] According to a first aspect of the present invention there
is provided an isolation barrier, comprising:
a tubular body having a throughbore, the tubular body arranged to
be run in and secured within a larger diameter generally
cylindrical structure; a valve housing located on the exterior of
the tubular body; a first sleeve member positioned on the exterior
of the tubular body with a first end being sealed thereto and a
second end being sealed to the valve housing to create a first
chamber within the first sleeve; a second sleeve member positioned
on the exterior of the tubular body with a first end being sealed
thereto and a second end being sealed to the valve housing to
create a second chamber within the second sleeve; first and second
rupturable barrier devices located at the first ends of the first
and second sleeves, respectively; and a valve arrangement located
in the valve housing, the valve arrangement having a first position
in which fluid flows from the throughbore to the first and second
chambers and a second position which prevents the flow of fluid
between the throughbore, the first chamber and the second
chamber.
[0015] In this way, the sleeves can be morphed together and by
rupturing the barriers, each side of the barrier is active to
pressure and collapse is prevented regardless of the pressure
differential across the barrier.
[0016] The large diameter structure may be an open hole borehole, a
borehole lined with a casing or liner string which may be cemented
in place downhole, or may be a pipeline within which another
smaller diameter tubular section requires to be secured or
centralised.
[0017] The tubular body is preferably located coaxially within the
first and second sleeves and is part of a tubular string used
within a wellbore, run into an open or cased oil, gas or water
well. Therefore the present invention allows a casing section or
liner to be centralised within a borehole or another downhole
underground pipe by provision of a morphable sleeve member
positioned around the casing or liner. Centralisation occurs as the
sleeve will expand radially outwardly at a uniform rate with the
application of pressure through the port. Additionally, the present
invention can be used to isolate one section of the downhole
annulus from another section of the downhole annulus and thus can
also be used to isolate one or more sections of downhole annulus
from the production conduit.
[0018] Preferably the valve arrangement has three branches, the
first branch being open to the throughbore, the second branch
connecting to the first sleeve member and the third branch
connecting to the second sleeve member. More preferably there is a
one-way check valve in the second branch and a one-way valve in the
third branch. In this way, pressurised fluid in the throughbore can
enter the first and second sleeves simultaneously but is prevented
from travelling back to the throughbore or between the
chambers.
[0019] Preferable the ruptureable barrier devices are rupture
disks, such as burst disk devices or the like. Preferably the
ruptureable barrier devices are set to rupture at pressures around
the morphed pressure value so that the sleeves are morphed prior to
rupture of the barrier devices.
[0020] Optionally, the first branch of the valve arrangement may
include a ruptureable barrier device. In this way, fluids can be
pumped down the tubing string into the well without fluids entering
the sleeves until it is desirous to morph the sleeves.
[0021] According to a second aspect of the present invention there
is provided a method of setting an isolation barrier in a well
bore, comprising the steps: [0022] (a) locating first and second
sleeve members side-by-side on the exterior of a tubular body and
sealing them thereto to create first and second chambers
therebetween; [0023] (b) running the tubular body on a tubular
member into a wellbore and positioning the sleeve members at a
desired location within a larger diameter structure; [0024] (c)
pumping fluid through the tubular member and increasing the fluid
pressure to provide fluid at a morphed pressure value at the sleeve
members; [0025] (d) simultaneously pumping fluid at the morphed
pressure value into the chambers causing the sleeves to move
radially outwardly and morph against an inner surface of the larger
diameter structure; [0026] (f) once morphed, preventing fluid from
passing between the tubular member and the chambers, and between
the chambers; and [0027] (g) creating an opening at a first end of
the first sleeve member and at a second end of the second sleeve
member.
[0028] In this way, once the morph is complete, fluid can enter
each sleeve from the annulus above and below the barrier. Each
sleeve thus supports the other sleeve and prevents collapse of the
barrier.
[0029] The large diameter structure may be an open hole borehole, a
borehole lined with a casing or liner string which may be cemented
in place downhole, or may be a pipeline within which another
smaller diameter tubular section requires to be secured or
centralised.
[0030] Preferably, step (d) includes the step of pumping fluid
through a valve arrangement between the sleeves. The step may also
include pumping fluid through two one way check valves, each
arranged at an input to each sleeve, respectively.
[0031] Preferably, the method includes the step of rupturing a disc
at the valve arrangement to allow fluid to enter the chambers when
the pressure reaches a desired value. This allows pumping of fluids
into the well without fluid entering the sleeve members.
[0032] The method may include the steps of running in a hydraulic
fluid delivery tool, creating a temporary seal above and below the
valve arrangement and injecting fluid from the tool into the
chambers via the valve arrangement.
[0033] In the description that follows, the drawings are not
necessarily to scale. Certain features of the invention may be
shown exaggerated in scale or in somewhat schematic form, and some
details of conventional elements may not be shown in the interest
of clarity and conciseness. It is to be fully recognized that the
different teachings of the embodiments discussed below may be
employed separately or in any suitable combination to produce the
desired results.
[0034] Accordingly, the drawings and descriptions are to be
regarded as illustrative in nature, and not as restrictive.
Furthermore, the terminology and phraseology used herein is solely
used for descriptive purposes and should not be construed as
limiting in scope. Language such as "including," "comprising,"
"having," "containing," or "involving," and variations thereof, is
intended to be broad and encompass the subject matter listed
thereafter, equivalents, and additional subject matter not recited,
and is not intended to exclude other additives, components,
integers or steps. Likewise, the term "comprising" is considered
synonymous with the terms "including" or "containing" for
applicable legal purposes.
[0035] All numerical values in this disclosure are understood as
being modified by "about". All singular forms of elements, or any
other components described herein including (without limitations)
components of the apparatus are understood to include plural forms
thereof.
[0036] Embodiments of the present invention will now be described,
by way of example only, with reference to the accompanying drawings
of which:
[0037] FIG. 1 is a cross-sectional view through an isolation
barrier according to an embodiment of the present invention;
and
[0038] FIG. 2 is a cross sectional view through the isolation
barrier of FIG. 1, following morphing.
[0039] Reference is initially made to FIG. 1 of the drawings which
illustrates an isolation barrier, generally indicated by reference
numeral 10, including a tubular body 12, sleeve members 14a,b with
chambers 16a,b and a valve arrangement 20, located between the
sleeve members 14a,b according to an embodiment of the present
invention.
[0040] Tubular body 12 is a cylindrical tubular section having at a
lower end (not shown), a box section and at an upper end (not
shown), a pin section for connecting the body 12 into a tubing
string such as casing, liner or production tubing that is intended
to be permanently set or completed in a well bore. Body 12 includes
a throughbore 30 which is co-linear with the throughbore of the
string.
[0041] Tubular body 12 is located coaxially within the sleeve
members 14a,b which are arranged side by side along the tubular
body 12. Sleeve members 14a,b are each a steel cylinder being
formed from typically 316L or Alloy 28 grade steel but could be any
other suitable grade of steel or any other metal material or any
other suitable material which undergoes elastic and plastic
deformation. The sleeve members 14a,b are appreciably thin-walled
of lower gauge than the tubing body 12 and are preferably formed
from a softer and/or more ductile material than that used for the
tool body 12. The sleeve members 14a,b may be provided with a
non-uniform outer surface 40a,b such as ribbed, grooved or other
keyed surface in order to increase the effectiveness of the seal
created by the sleeve members 14a,b when secured within another
casing section or borehole.
[0042] An elastomer or other deformable material may bonded to the
outer surface 40a,b of the sleeves 14a,b; this may be as a single
coating but is preferably a multiple of bands with gaps
therebetween. The bands or coating may have a profile or profiles
machined into them. In this way, the elastomer bands are spaced
such that when the sleeves 14a,b are being morphed the bands will
contact the inside surface 82 of the open borehole 80 first. The
sleeve members 14a,b will continue to expand outwards into the
spaces between the bands, thereby causing a corrugated effect on
the sleeve members 14a,b. These corrugations provide a great
advantage in that they increase the stiffness of the sleeve members
14a,b and increase their resistance to collapse forces.
[0043] The sleeves 14a,b are arranged oppositely so that a first
end 42a,b of each sleeve 14,b is at the centre of the barrier 10.
The first ends 42a,b are attached to a stop 44 machined in the
outer surface 36 of the body 12. Attachment is via pressure-tight
welded connections to provide a seal. An O-ring seal (not shown)
may also be provided between the inner surfaces 46a,b of the
sleeves 14a,b and the outer surface 36 of the body 12 to act as a
secondary seal or backup to the seal provided by the welded
connection at the stop 44. Attachment could also be by means of a
mechanical clamp. Stop 44 is an annular ring formed around the
circumference of the outer surface 36 of the body 12.
[0044] Second stops 48a,b are arranged at second ends 50a,b of the
sleeves 14a,b. The second stops 48a,b may be clamped to the body 12
so that the sleeves 14a,b can be slid onto the body 12 over the
ends during assembly. A seal 52a,b is provided at the outer surface
36 of the body 12 forward of the stop 48a,b so that the seal 52a,b
is between the sleeve 14a,b and the body 12. This provides a
sliding o-ring seal so that the second end 50a,b of each sleeve
14a,b is permitted to move towards the first stop 44 relative to
the body 12. Thus when the sleeve members 14a,b are caused to move
in the radially outward direction, this causes simultaneous
movement of the sliding seals 52a,b towards each other, which has
the advantage in that the thickness of the sleeves 14a,b is not
further thinned by the radially outwards expansion.
[0045] Stop 44 together with the inner surface 46a,b of each sleeve
14a,b and the outer surface 36 of the body 12, define chambers
16a,b, one in each sleeve 14a,b. While in FIG. 1, the chambers
16a,b have a distinct volume, this can be made near negligible by
arranging the sleeves 14a,b and body 12 close together. However,
following morphing the chamber 16a,b will have a volume within the
void created between the body 12 and the sleeves 14a,b.
[0046] Located in a portion of the stop 44 is a valve housing 22.
Valve housing 22 has three branches 24,26a,b which meet at a
junction 18 in the housing 22. A first branch 24 provides a path,
from a port 32 on the inner surface 38 of the body 12 through the
side wall 34 of the body 12, to provide a fluid passageway between
the throughbore 30 and the junction 18. A second branch 26a
provides a path from the junction 18 to the outer surface 36 of the
body 12 within the first chamber 16a. Similarly, a third branch 26b
provides a path from the junction 18 to the outer surface 36 of the
body 12 within the second chamber 16b. Thus a path exists between
the throughbore 30 at the port 32 to both of the chambers
16a,b.
[0047] Branches 24,26a,b form a valve arrangement 20. One way check
valves 28a,b are located in the branches 26a,b so that fluid can
only pass in a direction from the throughbore 30 into the chambers
16a,b. Fluid is prevented from escaping into the tubular body 12 or
the other chamber 16b,a. Thus the chambers 16a,b can be filled
simultaneously from fluid in the throughbore 30. The check valves
28a,b also close when the pressure within the chambers 16a,b
reaches a predetermined level, this being defined as the morphed
pressure value. Also arranged at the port 32 is a rupture disc 56.
The rupture disc 56 is rated to a pressure below, but close to the
morphed pressure value. In this way, the rupture disc 56 can be
used to control when the setting of the sleeves 14a,b is to begin.
The disc 56 can be operated by increasing pressure in the
throughbore 30 towards the morphed pressure value, but will prevent
fluid exiting the throughbore 30 into the chambers 16a,b until this
pressure value occurs.
[0048] At each end 50a,b of each sleeve 14a,b there is provided a
rupturable barrier device in the form of a burst disk 54a,b. For
ease of construction the burst disks 54a,b are shown mounted in the
end portions of the sleeves 14a,b, sometimes referred to as seal
carriers, but they may be located through the thinner portions if
desired. Mounting through the end portions ensures that they are
not morphed outwards and prevented from operating. Each disk, when
burst, provides a direct passageway for fluid to pass between each
chamber 16a,b and the annulus 42 between the outer surface 36 of
the tubular body 12 and the wall 82 of the borehole 80.
[0049] Reference will now be made to FIG. 2 of the drawings which
provides an illustration of the isolation barrier once set and is
used to describe a method for setting an isolation barrier within a
well bore according to an embodiment of the present invention. Like
parts to those in the earlier Figures have been given the same
reference numerals to aid clarity.
[0050] In use, the barrier 10 is conveyed into the borehole by any
suitable means, such as incorporating the barrier 10 into a casing
or liner string (not shown) and running the string into a wellbore
78 until it reaches the location within the open borehole 80 at
which operation of the barrier 10 is intended. This location is
normally within the borehole at a position where the sleeves 14a,b
are to be expanded in order to, for example, isolate the section of
borehole 80a located above the sleeves 14a,b from that below 80b in
order to provide an isolation barrier between the zones 80a,80b. It
will be appreciated that a further barrier can be run on the same
string 76 so that zonal isolation can be performed across a zone in
order that an injection, frac'ing or stimulation operation can be
performed on the isolated formation located between the two
barriers.
[0051] Each sleeve 14,a,b can be set by increasing the pump
pressure in the throughbore 30 to a predetermined value which
represents a pressure of fluid at the port 32 being the morphed
pressure value. The morphed pressure value will be calculated from
knowledge of the diameter of the body 12, the approximate diameter
of the borehole 80 at each sleeve 14a,b, the length of each sleeve
14a,b and the material and thickness of the sleeve 14a,b. The
morphed pressure value is the pressure sufficient to cause the
sleeve 14a,b to move radially away from the body 12 by elastic
expansion, contact the surface 82 of the borehole and morph to the
surface 82 by plastic deformation.
[0052] When the morphed pressure value is applied at the port 32,
the rupture disc 56 will have burst as it is set below the morphed
pressure value. Fluid will enter the first branch 24 and reach
junction 18 whereupon it will divide and enter the second 26a and
third 26b branches simultaneously. The check valves 28a,b are
arranged to allow fluid from the throughbore 30 to enter each of
the chambers 16a,b. This fluid will increase pressure in each
chamber 16a,b so as to cause each sleeve 14a,b to simultaneously
move radially away from the body 12 by elastic expansion, contact
the surface 82 of the borehole and morph to the surface 82 by
plastic deformation. When the morphing has been achieved, the check
valves 28a,b will close and trap fluid at a pressure equal to the
morphed pressure value within the chambers 16a,b. The check valves
28a,b prevent fluid from escaping from either chamber 16a,b back to
the throughbore or to the other chamber 16b,a.
[0053] The sleeves 14a,b will each have taken up a fixed shape
under plastic deformation with an inner surface 46a,b matching the
profile of the surface 82 of the borehole 80, and an outer surface
86a,b also matching the profile of the surface 82 to provide a seal
which effectively isolates the annulus 84a of the borehole 80 above
the barrier 10 from the annulus 86 below the sleeve 14.
[0054] When morphed pressure is reached in the sleeves 14a,b the
burst disks 54a,b are set to rupture. This may be at 10,000 psi,
say. This opens a fluid passageway between the lower annulus 84a
and the chamber 16b, and between the upper annulus 84b and the
chamber 16a. Thus each chamber 16a,b becomes active to the fluid
pressure on that side of the barrier 10. In this way, a pressure
differential is prevented from being established between the
annulus and the chamber on either end of the barrier 10. Collapse
of either sleeve 14a,b is therefore prevented.
[0055] If two barriers 10 are set together then zonal isolation can
be achieved for the annulus 84 between the barriers. At the same
time the sleeves 14a,b have effectively centered, secured and
anchored the tubing string 76 to the borehole 80.
[0056] An alternative method of achieving morphing of the sleeve
14a,b is shown in FIG. 1. This method uses a hydraulic fluid
delivery tool 88. Once the string 76 reaches its intended location,
tool 88 can be run into the string 76 from surface by means of a
coiled tubing 90 or other suitable method. The tool 88 is provided
with upper and lower seal means 92a,b, which are operable to
radially expand to seal against the inner surface 94 of the body 12
at a pair of spaced apart locations in order to isolate an internal
portion of body 12 located between the seals 92a,b; it should be
noted that said isolated portion includes the fluid port 32. Tool
88 is also provided with an aperture 96 in fluid communication with
the interior of the string 76.
[0057] To operate the tool 88, seal means 92 are actuated from the
surface to isolate the portion of the tool body 12. Fluid, which is
preferably hydraulic fluid, is then pumped under pressure, which is
set to the morphed pressure value, through the coiled tubing such
that the pressurised fluid flows through tool aperture 96 and then
via port 32 through the valve arrangement 20 and into chambers
16a,b and acts in the same manner as described hereinbefore.
[0058] A detailed description of the operation of such a hydraulic
fluid delivery tool 88 is described in GB2398312 in relation to the
packer tool 112 shown in FIG. 27 with suitable modifications
thereto, where the seal means 92a,b could be provided by suitably
modified seal assemblies 214, 215 of GB2398312, the disclosure of
which is incorporated herein by reference. The entire disclosure of
GB2398312 is incorporated herein by reference.
[0059] Using either pumping method, the increase in pressure of
fluid directly against the sleeves 14a,b causes the sleeves 14a,b
to move radially outwardly and seal against a portion of the inner
circumference of the borehole 80. The pressure within the chambers
16a,b continues to increase such that the sleeves 14a,b initially
experience elastic expansion followed by plastic deformation. The
sleeves 14a,b expand radially outwardly beyond their yield point,
undergoing plastic deformation until the sleeves 14a,b morph
against the surface 82 of the borehole 80 as shown in FIG. 2. If
desired, the pressurised fluid within the chamber 16a,b can be bled
off following plastic deformation of the sleeves 14a,b.
Accordingly, the sleeves 14a,b have been plastically deformed and
morphed by fluid pressure without any mechanical expansion means
being required.
[0060] When the morphing has been achieved, the check valves 28a,b
will close and trap fluid at a pressure equal to the morphed
pressure value within the chambers 16a,b. At the same time, the
burst disks 54a,b will rupture allowing annulus fluid to enter each
chamber 16a,b or morph fluid to escape into the annulus until there
is zero pressure differential at the first ends 50a,b of each
sleeve 14a,b. Any change in the pressure within the chambers 16a,b
or in the annulus 84a,b is transmitted between the two to maintain
a zero differential pressure.
[0061] The principle advantage of the present invention is that it
provides an morphed isolation barrier in a well bore which is
resistive to collapse.
[0062] A further advantage of the present invention is that it
provides a method for setting a morphed isolation barrier in a well
bore which allows multiple barriers to be set simultaneously in the
well bore.
[0063] A yet further advantage of the present invention is that it
provides an isolation barrier in a well bore in which pressure
within a morphed sleeve is matched to that of the neighboring
annulus so that the thickness of the sleeve can be reduced to
improve the sealing contact during morphing.
[0064] It will be apparent to those skilled in the art that
modifications may be made to the invention herein described without
departing from the scope thereof. For example, while a morphed
pressure value is described this may be a pressure range rather
than a single value to compensate for variations in the pressure
applied at the sleeves in extended well bores. Each sleeve 14a,b
may be independently morphed. There may be a fluid exclusion means
located between the sleeves 14a,b to prevent hydraulic lock at the
centre during morphing.
* * * * *