U.S. patent application number 12/040874 was filed with the patent office on 2009-09-03 for reservoir tool for packer setting.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Stephen J. Chauffe.
Application Number | 20090218107 12/040874 |
Document ID | / |
Family ID | 41012293 |
Filed Date | 2009-09-03 |
United States Patent
Application |
20090218107 |
Kind Code |
A1 |
Chauffe; Stephen J. |
September 3, 2009 |
Reservoir Tool for Packer Setting
Abstract
An external casing packer with a packer element is fashioned
from materials that physically expand ("swell") in response to
contact by an appropriate swelling fluid. In preferred embodiments,
the packer element is fashioned of a swellable elastomer, and the
swelling fluid is an oil or water-based fluid that is effective to
swell the particular elastomer used.
Inventors: |
Chauffe; Stephen J.; (The
Woodlands, TX) |
Correspondence
Address: |
SHAWN HUNTER
P.O Box 270110
HOUSTON
TX
77277-0110
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
41012293 |
Appl. No.: |
12/040874 |
Filed: |
March 1, 2008 |
Current U.S.
Class: |
166/387 ;
166/187 |
Current CPC
Class: |
E21B 33/1208
20130101 |
Class at
Publication: |
166/387 ;
166/187 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Claims
1. An packer device for providing a seal between a string of casing
and a borehole wall, the device comprising: a packer element
substantially formed of a material that swells in response to
contact by a swelling fluid; a fluid reservoir containing a
swelling fluid that causes the packer element to swell upon
contact; and a distribution conduit for transmitting the swelling
fluid from the reservoir to the packer element.
2. The packer device of claim 1 wherein the distribution conduit
further comprises a nozzle that is disposed within the packer
element, the nozzle having a plurality of fluid openings.
3. The packer device of claim 1 wherein the swelling fluid
comprises a water-based fluid.
4. The packer device of claim 1 wherein the swelling fluid
comprises an oil-based fluid.
5. The packer device of claim 1 wherein the packer element is
substantially formed of a swellable elastomer.
6. The packer device of claim 1 wherein there is a plurality of
fluid reservoirs.
7. The packer device of claim 1 wherein the fluid reservoir further
comprises: a reservoir body containing the swelling fluid; an
opening in the reservoir body; and a piston moveably disposed
within the reservoir body between the opening and the swelling
fluid, the piston forming a fluid seal against the reservoir body
and moveable in response to annular fluid pressure.
8. A packer device for providing a seal between a string of casing
and a borehole wall, the device comprising: a central packer
mandrel for incorporation into the string of casing; a packer
element radially surrounding the mandrel and substantially formed
of an elastomeric material that swells in response to contact by a
swelling fluid; a fluid reservoir containing a swelling fluid that
causes the packer element to swell upon contact; and a distribution
conduit for transmitting the swelling fluid from the reservoir to
the packer element.
9. The packer device of claim 8 wherein the fluid reservoir further
comprises: a reservoir body containing the swelling fluid; an
opening in the reservoir body; and a piston moveably disposed
within the reservoir body between the opening and the swelling
fluid, the piston forming a fluid seal against the reservoir body
and moveable in response to annular fluid pressure.
10. The packer device of claim 8 wherein the distribution conduit
further comprises a nozzle that is disposed within the packer
element, the nozzle having a plurality of fluid openings.
11. The packer device of claim 8 wherein the swelling fluid
comprises a water-based fluid.
12. The packer device of claim 8 wherein the swelling fluid
comprises an oil-based fluid.
13. A method of forming a packer seal between a string of casing
and a surrounding well bore wall, the method comprising the steps
of: integrating a packer device into the string of casing, the
packer device comprising: a) a packer element substantially formed
of an elastomeric material that swells in response to contact by a
swelling fluid; and b) a fluid reservoir containing a swelling
fluid that causes the packer element to swell upon contact;
disposing the string of casing and packer device into a wellbore;
flowing the swelling fluid from the fluid reservoir to the packer
element to cause the packer element to swell and form a seal
against the surrounding well bore wall.
14. The method of claim 13 wherein the step of flowing the swelling
fluid from the fluid reservoir to the packer element further
comprises urging a piston against the swelling fluid within the
fluid reservoir.
15. The method of claim 14 wherein the piston is urged against the
swelling fluid in response to increased fluid pressure within an
annulus surrounding the string of casing.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to devices and methods for
setting packers within a wellbore. In more particular aspects, the
invention relates to the setting of swellable packers.
[0003] 2. Description of the Related Art
[0004] Packers are used to create a fluid seal within a wellbore.
One type of packer is an external casing packer. External casing
packers are packer devices that are incorporated into a string of
casing and used to secure the string of casing within an open
borehole pending completion of a cementing operation which will
permanently secure the casing string within the wellbore. External
casing packers are intended to be permanently set and remain in the
bore hole following cementing.
[0005] Typically, an external casing packer includes a central
mandrel having a central axial passage the is the same diameter as
the interior casing diameter. The packer device is located on the
external diameter of the mandrel. The packer is actuated between an
unset position and a set position. In the set position, the packer
is expanded radially and makes sealing contact with the surrounding
wellbore wall. Examples of conventional external casing packers are
found in U.S. Pat. No. 5,201,369 issued to Berzin et al., which is
owned by the assignee of the present invention and is herein
incorporated by reference.
SUMMARY OF THE INVENTION
[0006] The invention provides a new type of external casing packer
wherein the packer element is fashioned from materials that
physically expand ("swell") in response to contact by an
appropriate swelling fluid. In preferred embodiments, the packer
element is fashioned of a swellable elastomer, and the swelling
fluid is an oil or water-based fluid that is effective to swell the
particular elastomer used.
[0007] In a related aspect, the invention provides a mechanism for
activating and radially expanding the packer element into sealing
engagement with the surrounding borehole wall. In a preferred
embodiment, the activating mechanism includes one or more fluid
reservoirs which are mounted upon the exterior surface of the
packer mandrel. In preferred embodiments, the fluid reservoir(s)
are provided with one or more fluid injection nozzles which are
operably associated with the packer element to provide fluid
transmission from the reservoir(s) into portions of the packer
element. The fluid reservoir(s) contain amounts of oil or
water-based fluids that are sufficient to cause swelling of the
packer element and radial expansion of the packer element into
sealing engagement with the surrounding wellbore wall. In currently
preferred embodiments, as well, the reservoir(s) contain a piston
that is in contact with the fluid and moveable within the
reservoir. In operation, external pressure within the annulus
surrounding the casing string will urge the piston of each
reservoir against the fluid contained therein and cause the fluid
to flow out of the injection nozzles and into the packer
element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For detailed understanding of the invention, reference is
made to the following detailed description of the preferred
embodiments, taken in conjunction with the accompanying drawings in
which reference characters designate like or similar elements
throughout the several figures of the drawings.
[0009] FIG. 1 is a side, partial cross-sectional view of an
exemplary casing string within a wellbore containing a packer
device constructed in accordance with the present invention.
[0010] FIG. 2 is a side, partial cross-sectional view of the packer
device shown in FIG. 1, in an unactivated condition.
[0011] FIG. 3 is a side, partial cross-sectional view of the device
shown in FIGS. 1 and 2, now in an activated condition.
[0012] FIG. 4 is a side, cross-sectional view of an exemplary
activating mechanism used with the external casing packer of FIGS.
1-3, in accordance with the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] FIG. 1 schematically depicts an exemplary open bore hole 10
which has been drilled into the earth 12. A string 14 of metallic
casing sections 16, of a type known in the art, is shown disposed
within the open hole 10. The casing string 14 defines an axial
flowbore 18 along its length. An annulus 20 is defined between the
exterior surface 22 of the casing string 14 and the interior wall
24 of the bore hole 10.
[0014] An external casing packer device 26 in accordance with the
present invention is incorporated into the casing string 14.
Construction and operation of the packer device 26 is better
understood with further reference to FIGS. 2 and 3. The packer
device 26 includes a central packer mandrel 28 that is generally
cylindrical and defines a central flowbore 30. The mandrel 28 has
first and second axial ends 32, 34 that have threaded connections
to permit the mandrel 28 to be affixed to adjacent casing sections
16 and thereby incorporated into the casing string 14.
[0015] A packer element 36 radially surrounds the mandrel 28 and is
secured thereto. The packer element 36 is formed of a swellable
material. In preferred embodiments, the packer element 36 is
fashioned of a swellable elastomer. Swellable elastomers are known
materials that physically expand, or swell, in response to contact
with certain swelling fluids. Swelling of the elastomer occurs due
to absorption of the appropriate swelling fluid by the elastomer.
Currently, there are two basic swellable elastomers: elastomers
that are swellable in response to water-based fluids, and
elastomers that are swellable in response to oil-based fluids.
[0016] A plurality of packer activation devices 40 are also mounted
upon the outer radial surface of the mandrel 28. Although there are
a plurality of activation devices 40 shown, there may in fact, be
only a single activation device 40, if desired. FIG. 4 depicts an
exemplary packer activation device 40 in greater detail. The
activation device 40 includes a fluid reservoir 42. In the
embodiment depicted, the reservoir 42 is substantially cylindrical
in shape. However, other shapes may be used. A fluid distribution
conduit with nozzle 44 extends downwardly from the lower end of the
reservoir 42. The reservoir 42 is filled with a swelling fluid 46.
In some preferred embodiments, the swelling fluid 46 comprises a
water-based fluid such as fresh water. In other preferred
embodiments, the swelling fluid 46 comprises an oil-based fluid,
such as kerosene or diesel. The type swelling fluid 46 is
determined by the type of swellable elastomer that is used to form
the packer element 36.
[0017] The nozzle 44 includes a plurality of fluid openings 48. The
openings 48 may be variously shaped, sized and spaced to ensure
optimal disposition of the swelling fluid 46 within the packer
element 36. The activation devices 40 may be secured to the mandrel
28 by straps (not shown), welding, connectors, or in other ways
known in the art. When the activation devices 40 are secured to the
mandrel 28, the nozzles 44 are disposed within the packer element
36. In a currently preferred embodiment, the nozzles 44 are
disposed within the packer element 36 as the packer element 36 is
formed onto the mandrel 28 by wrapping of several layers. As the
layers of the element 36 are wrapped around the mandrel 28, the
nozzles 44 are disposed between overlapping layers. In alternative
embodiments, the nozzles 44 may be disposed within the packer
element 36 by molding them into the element 36 as it is cast upon
the mandrel 28 or by forming openings in the element 36 within
which the nozzles 44 can reside.
[0018] A piston 50 is disposed within each reservoir 42 atop the
swelling fluid 46. The piston 50 forms a fluid seal against the
interior wall of the reservoir 42. An opening 52 is formed in the
reservoir body 42, and the piston 50 is moveably disposed within
the reservoir body 42 between the fluid 46 and the opening 52.
[0019] In operation, the packer device 26 is first incorporated
into the casing string 14. The casing string 14 is run into the
wellbore 10. Thereafter, fluid pressure is increased within the
annulus 20. This may be accomplished by filling the annulus 20 with
a fluid, such as drilling fluid or water, and then increasing fluid
pressure within the annulus 20 from the surface using a pump (not
shown) or hydrostatic pressure, in a manner known in the art. As
fluid pressure rises in the annulus 20, it will act upon the piston
50 and urge the piston 50 against the swelling fluid 46 to cause
the swelling fluid 46 to flow outwardly through the nozzles 44 and
be absorbed into the packer element 36. The swelling fluid 46 will
cause the packer element 36 to expand radially and thereby form a
seal against the surrounding wall 10, as depicted in FIG. 3.
[0020] Those of skill in the art will recognize that numerous
modifications and changes may be made to the exemplary designs and
embodiments described herein and that the invention is limited only
by the claims that follow and any equivalents thereof.
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