SWELLABLE SCREEN ASSEMBLY
Technical Field of the Invention
[0001] The present Invention relates generally to control screens for
subterranean fluid production and, more particularly (although not necessarily
exclusively), to a sweilable screen assembly having support material for a tube.
Background
[0002] Hydrocarbons can be produced through a wellbore traversing a
subterranean formation, in some cases, the formation may be unconsolidated or
loosely consolidated. Particulate materials, such as sand, from these types of
formations may be produced together with the hydrocarbons. Production of particulate
materials presents numerous problems. Examples of problems include particulate
materials being produced at the surface, causing abrasive wear to components within a
production assembly, partially or fully clogging a production interval, and causing
damage to production assemblies by collapsing onto part or all of the production
assemblies.
[0003] Expandable sand control screens can be used to provide stability to a
formation to prevent or reduce collapses and filter particulate materials from
hydrocarbon fluids. Expandable sand control screens can include a sweilable material,
such as a high-swelling rubber, and a filter device on the exterior of the sweilable
material. The sweilable material can be located proximate the production interval and,
when activated by a fluid, expand to displace the filter device to the wellbore. The filter
device can include perforations through which hydrocarbon fluids from the formation
can be received and directed into a production pipe. This type of expandable sand
control screen can be effective in filtering and providing formation stability.
[0004] In some applications, however, the sweilable material may expand into
the perforations after contacting the activating fluid. Expanding into the perforations
may result in the sweilable material partially or completely plugging the perforations of
the filter device. Plugged perforations can reduce or prevent hydrocarbon fluids from
flowing to an internal flow path of the production pipe. A rework of the control screen
assembly may be required to alleviate the plugging. Reworks cost substantial time and
money because they require suspension of hydrocarbon production for a measurable
amount of time and require duplication of work in locating the control screen assembly
in the wellbore.
[0005] Therefore, screen assemblies that can provide radial support to
formations and reduce or eliminate plugging are desirable. Methods of manufacturing
screen assemblies that can reduce or eliminate plugging are also desirable.
Summary
[0006] Certain embodiments of the present invention are directed to screen
assemblies that can receive hydrocarbon fluids from a hydrocarbon-bearing
subterranean formation and reduce or eliminate plugging. Reducing or eliminating
plugging can reduce or eliminate need for a rework. The screen assemblies may
include a tube and a support material exterior to swellable material. The tube can be
configured to receive hydrocarbon fluids from the formation. The support material can
prevent or reduce plugging of the tube by the swellable material when the swellable
material expands. Certain screen assemblies can also provide stability to a
subterranean formation.
[0007] In one aspect, a screen assembly capable of being disposed in a bore is
provided. The screen assembly can include a swellable material, a tube, and a support
material. The swellable material can be disposed exterior to a base pipe. The tube can
be disposed exterior to the swellable material. The support material can be disposed
between the swellable material and the tube. In response to contact with an activating
fluid, the swellable material is capable of expanding and displacing at least part of the
tube toward a surface of the bore. The swellable material can expand more than the
support material in response to the activating fluid.
[0008] In one embodiment, the support material is a low-swelling rubber
compound.
[0009] In one embodiment, the support material is a non-swelling rubber
compound that can retain an initial shape when the swellable material expands.
[0010] In one embodiment, the swellable material includes a groove and the tube
and the support material are disposed in the groove.
[0011] In one embodiment, the tube is a filtration tube that includes a filter media
for filtering particulate materials from hydrocarbon fluids.
[0012] In one embodiment, the tube includes perforations. The support material
can isolate at least part of the perforations from the swellable material.
[0013] In one embodiment, the support material is hydrogenated nitrile butadiene
rubber (HNBR).
[0014] In one aspect, a screen assembly that can be disposed in a bore is
provided. The screen assembly includes a swellable material, a tube, and a support
material. The swellable material is disposed exterior to a base pipe. The tube includes
perforations and is disposed exterior to the swellable material. The support material is
disposed between the swellable material and the tube. The support material can
isolate at least part of the perforations from the swellable material. In response to
contact with an activating fluid, the swellable material can expand and displace at least
part of the tube toward a surface of the bore.
[0015] In one aspect, a method of manufacturing a screen assembly capable of
being disposed in a bore is provided. The method of manufacturing includes
positioning a casting member exterior to a base pipe. Support material is positioned
between the casting member and the base pipe. A swellable material is positioned
between the support material and the base pipe. The swellable material can expand in
response to an activating fluid. The swellable material is processed to form a groove in
which the casting member and the support material are disposed. The casting member
is removed from the groove. A tube is positioned in the groove.
[0016] In one embodiment, a framing member is positioned exterior to the base
pipe. The casting member is positioned exterior to the base pipe by coupling the
casting member to the framing member. In one embodiment, the tube is a filtration tube
comprising a filter media capable of filtering particulate materials from hydrocarbon
fluid.
[0017] These illustrative aspects and embodiments are mentioned not to limit or
define the invention, but to provide examples to aid understanding of the inventive
concepts disclosed in this application. Other aspects, advantages, and features of the
present invention will become apparent after review of the entire application.
Brief Description of the Drawings
[0018] Figure 1A is a schematic illustration of a well system having screen
assemblies in a running configuration according to one embodiment of the present
invention.
[0019] Figure 1B is a schematic illustration of a well system having screen
assemblies in an operating configuration according to one embodiment of the present
invention.
[0020] Figure 2A is a cross sectional view along line 2A-2A of a screen assembly
of Figure 1A in a running configuration according to one embodiment of the present
invention.
[0021] Figure 23 is a cross sectional view along line 2B-2B of a screen assembly
of Figure 1B In a running configuration according to one embodiment of the present
invention.
[0022] Figure 3 is a side view of a screen assembly according to one
embodiment of the present invention.
[0023] Figure 4A is a cross sectional view of a screen assembly in a running
configuration according to one embodiment of the present invention.
[0024] Figure 4B is a cross sectional view of a screen assembly in an operating
configuration according to one embodiment of the present Invention.
[0025] Figure 5 is a perspective view of a base pipe and framing members
according to one embodiment of the present invention.
[0026] Figure 6 is a perspective view of the casting members coupled to the
framing members of Figure 5 according to one embodiment of the present invention.
[0027] Figure 7 is a perspective view of support material positioned between the
base pipe and the casting members of Figure 6 according to one embodiment of the
present invention.
[0028] Figure 8 is a perspective view of swellable material positioned on the
base pipe of Figure 7 according to one embodiment of the present invention.
[0029] Figure 9 is a perspective view of a groove in the sweilable material of
Figure 8 after removing the casting members and framing members according to one
embodiment of the present invention.
[0030] Figure 10 is a perspective view of tubes positioned in the grooves of
Figure 9 according to one embodiment of the present Invention.
Detailed Description
[0031] Certain aspects and embodiments of the present invention relate to
screen assemblies capable of being disposed in a bore, such as a wellbore, of a
subterranean formation for use in producing hydrocarbon fluids from the formation.
The screen assemblies may be configured to support tubes and reduce or eliminate
plugging of the tubes by swellable material. Screen assemblies according to some
embodiments include a support material between a tube and swellable material located
exterior to a base pipe. The tube can include perforations and can receive and direct
hydrocarbon fluids from the formation. The swellable material can expand after contact
with an activating fluid and can displace the tube toward a surface of the bore. The
swellable material can expand more than the support material and the support material
can reduce or prevent plugging of the perforations by the swellable material expanding.
For example, the support material can isolate the perforations from the swellable
material.
[0032] The support material may be any material that can retain an initial shape
after contact with the activating fluid or otherwise expand a relatively low amount after
contact with the activating fluid. Examples of support material can include a low
swelling rubber compound, a non-swelling rubber compound, a polymer, and a metal.
Examples of suitable metals from which support material may be made can include
steel, iron, brass, copper, bronze, tungsten, titanium, cobalt, nickel, or a combination of
these or other types of materials. An example of a rubber compound that may be
suitable for support material includes hydrogenated nitrile butadiene rubber (HNBR).
[0033] Figure 1A shows a well system 10 with screen assemblies according to
certain embodiments of the present invention. The well system 10 includes a bore that
is a wellbore 12 extending through various earth strata. The wellbore 12 has a
substantially vertical section 14 and a substantially horizontal section 18. The
substantially vertical section 14 includes a casing string 16 cemented at an upper
portion of the substantially vertical section 14. The substantially horizontal section 18 is
open hole and extends through a hydrocarbon bearing subterranean formation 20.
[0034] A tubing string 22 extends from the surface within wellbore 12. The
tubing string 22 can provide a conduit for fonnation fluids to travel from the substantially
horizontal section 18 to the surface. Screen assemblies 24 are positioned with the
tubing string 22 in the substantially horizontal section 18. The screen assemblies 24
are shown in a running or unextended configuration. In some embodiments, screen
assemblies 24 are sand control screen assemblies that can receive hydrocarbon fluids
from the formation, direct the hydrocarbon fluids for filtration or otherwise, and stabilize
the formation 20.
[0035] Figure 1B shows the well system 10 with screen assemblies 24 in an
operating or a radially expanded configuration. Each of the screen assemblies 24 can
include a base pipe, a swellable material, one or more tubes, and support material.
The swellable material may be a relatively high swelling rubber compound or polymer
and can be disposed exterior to at least part of the base pipe. The tubes may be
located exterior to the swellable material. The tubes can include perforations for
receiving hydrocarbon fluids from the formation. The tubes can direct the hydrocarbon
fluids toward an internal flow path of the base pipe and can provide support to the
formation. In some embodiments, the tubes are filtration tubes that can filter particulate
materials from the hydrocarbon fluids. The support material can be located between
the swellable material and the tubes and can reduce or prevent plugging by the
swellable material in an operating configuration. For example, the support material can
isolate one or more perforations from the swellable material. Some embodiments of
the screen assemblies 24 also include an outer housing disposed exterior to part of the
base pipe that can receive hydrocarbon fluids from tubes and direct the hydrocarbon
fluids to the internal flow path of the base pipe.
[0036] When an activating fluid contacts the screen assemblies 24, the swellable
material of each of the screen assemblies 24 can expand. Expansion of the swellable
material can displace tubes of the screen assemblies 24 to contact a surface of
wellbore 12. The activating fluid may be any fluid to which the swellable material
responds by expanding. Examples of activating fluid include hydrocarbon fluids, water,
and gasses.
[0037] Figures 1A and 1B show tubing string 22 with screen assemblies 24.
Tubing strings according to various embodiments of the present invention, however,
may include any number of other tools and systems in addition to screen assemblies
24. Examples of other tools and systems include fluid flow control devices,
communication systems, and safety systems. Tubing string 22 may also be divided
into intervals using zonal isolation devices such as packers. Zonal isolation devices
may be made from materials that can expand upon contact with a fluid, such as
hydrocarbon fluids, water, and gasses.
[0038] In addition, figures 1A and 1B show screen assemblies 24 according to
certain embodiments of the present invention in the substantially horizontal section 18
of the wellbore 12. Screen assemblies according to various embodiments of the
present invention, however, can be used in other types of wellbores, such as deviated,
vertical, or multilateral wellbores. Deviated wellbores may include directions different
than, or in addition to, a general horizontal or a general vertical direction. Multilateral
wellbores can include a main wellbore and one or more branch wellbores. Directional
descriptions are used herein to describe the illustrative embodiments but, like the
illustrative embodiments, should not be used to limit the present invention.
[0039] Screen assemblies according to some embodiments of the present
invention can be disposed in an injection well. In an injection well, water or other fluid
is injected into the well to increase flow of hydrocarbon fluids to a nearby production
well. One or more screen assemblies can be disposed in the injection well to provide
support during and after the fluid injection process. In some embodiments, injected
fluid exits a base pipe through openings in the base pipe and perforations in the tubes.
Support material can reduce or prevent plugging of the perforations by swellable
material in an operating configuration to permit injected fluids to exit the perforations,
[0040] In addition, screen assemblies according to some embodiments of the
present invention can be disposed in a cased hole completion. In a cased hole
completion, a large diameter pipe is positioned between a production string and a
formation. The large diameter pipe may be a base pipe and swellable material can be
disposed exterior to at least part of the large diameter pipe. One or more tubes can be
located exterior to the swellable material and support material can be located between
the swellable material and the tubes.
[0041] Figures 2A and 2B show cross-sectional views of part of a screen
assembly 24 from Figures 1A (running configuration) and 1B (operating configuration),
respectively. Figures 2A and 2B illustrate a base pipe 102 that defines an internal flow
path 104 through which hydrocarbon fluids, for example, can flow. The base pipe 102
is disposed in a bore 106 in a formation 108. A swellable material 110 surrounds an
exterior of the base pipe 102. The swellable material 110 may be coupled to the base
pipe 102, such as by bonding or other suitable technique.
[0042] Tubes 112 are positioned on an exterior of the swellable material 110.
Figure 2A shows eight tubes 112, but screen assemblies according to various
embodiments of the present invention can include any number, from one to many, of
tubes 112. Each of the tubes 112 can include perforations that can receive
hydrocarbon fluid from the formation 108 in an operating configuration and direct the
hydrocarbon fluids to an internal flow path 104. For example, tubes 112 may direct
hydrocarbon fluids to a housing in which the hydrocarbon fluids are filtered and
provided to the internal flow path 104.
[0043] In some embodiments, tubes 112 are filtration tubes that can filter
particulate materials from the hydrocarbon fluids and can direct the filtered hydrocarbon
fluids to the internal flow path 104 through openings in the base pipe 102. The filtration
tubes may each include a filter housing for filter material. The filter material can include
a filtration opening through which hydrocarbon fluid can be directed to an opening in
the base pipe 102. The filter housing may be made of any suitable material and may
be partially perforated to allow hydrocarbon fluids to enter the filter housing. The filter
material may be any suitable material, such as a fine mesh, that can filter particulate
materials from hydrocarbon fluid.
[0044] Support material 114 is located between each of the tubes 112 and the
swellable material 110. For example, the swellable material 110 may include one or
more grooves. Support material 114 and one of the tubes 112 can be located in each
groove. Support material 114 may be a relatively low swelling or a non-swelling
material that can prevent or reduce swellable material 110 from plugging perforations in
the tubes 112. The support material 114 can isolate perforations in the tubes 112 from
the swellable material 110 when the swellable material 110 expands. Examples of
support material 114 can include a low swelling rubber compound, a non-swelling
rubber compound, a polymer, and a metal. Examples of a low swelling or a non-
swelling rubber compound include HNBR. Examples of suitable metals from which
support material 114 can be made can include steel, iron, brass, copper, bronze,
tungsten, titanium, cobalt, nickel, or a combination of these or other types of materials.
In some embodiments, the support material 114 is coupled to one or both of the
swellable material 110 and tubes 112 through bonding or other suitable technique.
[0045] The swellable material 110 can expand after contacting an activating fluid
and can displace the tubes 112 to contact the formation 108 at an internal diameter of a
bore 106, as shown in Figure 2B. Examples of activating fluid include hydrocarbon
fluids, gasses, and water. The swellable material 110 can expand more than the
support material 114, which may be configured to expand some after contacting an
activating fluid or configured to expand none and retain its initial shape after contacting
an activating fluid.
[0046] Various techniques can be used to contact the swellable material 110 with
an activating fluid. One technique includes configuring the swellable material 110 to
expand upon contact with activating fluids already present within the bore when the
screen assembly is installed or with activating fluids produced by the formation 108
after installation. The swellable material 110 may include a mechanism for delaying
swell to prevent swelling during installation. Examples of a mechanism for delaying
swell include an absorption delaying layer, coating, membrane, or composition.
Another technique includes circulating activating fluid through the well after the screen
assembly is installed in the well. In other embodiments, swellable material 110 is
capable of expansion upon its location in an environment having a temperature or a
pressure that is above a pre-selected threshold in addition to or instead of an activating
fluid.
[0047] Expansion of the swellable material 110 can displace the tubes 112 to
contact the formation 108. The thickness of the swellable material 110 can be
optimized based on the diameter of the screen assembly and the diameter of the bore
106 to maximize contact area of the tubes 112 and swellable material 110 with the
formation 108 upon expansion. Part of the swellable material 110 can expand between
the tubes 112 and contact the formation 108 between the tubes 112 to conform to non-
uniform bore diameters, for example. The support material 114 can isolate tube
perforations from the swellable material 110 and prevent the swellable material 110
from expanding to plug perforations or other openings in tubes 112.
[0048] The swelled screen assembly can reduce or eliminate annular flow of
hydrocarbon and other fluids, provide multiple flow paths for hydrocarbon fluids and
provide stabilization to the formation 108. For example, the swelled screen assembly
can support the formation 108 to prevent fonnation collapse. In some embodiments,
the swelled screen assembly can provide an amount of collapse support within a range
of 500 psi to 2000 psi (3.4 MPa to 14 MPa).
[0049] Screen assemblies according to some embodiments of the present
invention can include other components in addition to tubes for collecting hydrocarbon
fluid. Figure 3 shows one embodiment of a screen assembly 202 in a running
configuration that includes an outer housing 204 and a fluid collection subassembly
206. The fluid collection subassembly 206 includes swellable material 208 disposed
exterior to part of a base pipe 210. The base pipe 210 defines an interna! flow path
211 for hydrocarbon fluid flow. Tubes 212 are disposed exterior to the swellable
material 208. The swellable material 208 can expand after contacting an activating
fluid to displace the tubes 212 toward a formation. Each of the tubes 212 includes
perforations 214 that are capable of receiving hydrocarbon fluids from the formation
and directing the hydrocarbon fluids to the outer housing 204 in an operating
configuration. For each of the tubes 212, support material 216 is located between the
tube and the swellable material 208. The support material 216 can be a low swelling or
non-swelling material that can reduce or prevent plugging of the perforations 214 by the
swellable material 208, such as by isolating the perforations 214 from the swellable
material 208.
[0050] The outer housing 204 is disposed exterior to a second portion of the
base pipe 210. The outer housing 204 is also located in series with the fluid collection
subassembly 206 such that fluid passes through the fluid collection subassembly 206
before entering the outer housing 204. The outer housing 204 defines an annular
chamber 218 exterior to the second portion of the base pipe 210. The second portion
of the base pipe 210 includes openings 220 in a sidewall of the base pipe 210 through
which fluid can flow from the annular chamber 218 to internal flow path 211. Filter
mediums 222 are disposed exterior to the openings 220 and can filter particulate
materials from hydrocarbon fluids before the hydrocarbon fluids flow through openings
220 to the internal flow path 211.
[0051] Each of the filter mediums 222 can include a filter housing 224 in which a
filter material 226 is disposed. Part or the entire filter housing 224 may be perforated to
allow hydrocarbon fluids to flow in and out of the filter mediums 222. The filter material
226 may be a wire mesh material that can filter particulate materials from hydrocarbon
fluids.
[0052] In an operating configuration, the swellable material 208 expands after
contacting an activating fluid, such as hydrocarbon fluids, a gas, or water. Expansion
of the swellable material 208 displaces tubes 212 to a formation. At least part of the
tubes 212 and part of the swellable material 208 may contact an inner diameter of the
formation to provide support to the formation. The hydrocarbon fluids produced by the
formation can flow through perforations 214 into one or more tubes 212. The tubes
212 can direct the hydrocarbon fluids to the annular chamber 218 of outer housing 204.
The support material 216 can prevent or reduce plugging of the perforations 214 by the
swellable material 208 expanding or othenwise. For example, the support material 216
may be a material that does not expand or expands less than the swellable material
208 after contacting an activating fluid and isolates the perforations 214 from the
swellable material 208.
[0053] The hydrocarbon fluids in the annular chamber 218 can flow through the
filter mediums 222 to openings 220 of base pipe 210. The filter mediums 222 can filter
particulate materials from the hydrocarbon fluids. The filter hydrocarbon fluids can flow
through openings 220 to the internal flow path 211 of the base pipe 210. The
hydrocarbon fluids can flow to a surface through internal flow path 211.
[0054] The outer housing 204 depicted in Figure 3 includes filter mediums 222.
In other embodiments of the present invention the outer housing 204 can include
different or additional components that are configured to filter hydrocarbon fluids,
control hydrocarbon fluid flow, or otherwise assist in hydrocarbon production.
Examples of these components include inflow control devices and fluid discriminators.
Inflow control devices can controllably allow and prevent fluid flow. Fluid discriminators
can be configured to select a type of fluid, such as hydrocarbon fluid, for which to allow
flow and prevent other types of fluid, such as gas and water, from flowing.
[0055] Screen assemblies according to some embodiments of the present
invention include tubes that are filter mediums capable of filtering hydrocarbon fluids
produced by a formation and capable of directing filtered hydrocarbon fluids to an
internal flow path of a base pipe. Figures 4A-4B illustrate a cross-sectional view of
screen assembly 302 with tubes 304 that are filter mediums in a running configuration
(Figure 4A) and an operating configuration (Figure 4B).
[0056] The screen assembly 302 is disposed in a bore 306 in a hydrocarbon
fluid-producing fonnation 308. The screen assembly 302 includes a swellable material
310 disposed exterior to a base pipe 312. The base pipe 312 defines an internal flow
path 314 and the base pipe 312 includes openings 316 in a sidewall portion of the base
pipe 312. The openings 316 provide a fluid flow path to the interna! flow path 314 of
the base pipe 312.
[0057] The tubes 304 are disposed exterior to at least part of the swellable
material 310. Support material 318 is located between each of the tubes 304 and the
swellable material 310. In some embodiments, each of the tubes 304 and its
corresponding support material 318 are located in a groove of the swellable material
310. Each of the tubes 304 can include perforations 320, a filter material, and an
opening 321. Hydrocarbon fluids from the formation 308 can enter the tubes 304
through the perforations 320 and the filter material can filter particulate materials from
the hydrocarbon fluids.
[0058] Pistons 322 can be located in openings 316 and can be coupled to the
tubes 304. The pistons 322 include a telescoping portion that can extend from the
openings 316 of the base pipe 312 in an operating configuration.
[0059] In the operating configuration, the swellable material 310 expands after
contacting an activating fluid, such as hydrocarbon fluid, gas, or water. Expansion of
the swellable material 310 displaces the tubes 304 to the formation 308. At least part
of the tubes 304 and part of the swellable material 310 can contact the formation 308.
The tubes 304 and swellable material 310 may support the formation 308 at a
production interval to prevent formation collapse, for example. The support material
318 can retain its initial shape or othenwise can expand less than the swellable materia!
310 and can isolate openings 321 from the swellable material 310 to reduce or prevent
plugging. The telescoping portion of each of the pistons 322 can extend from the
openings 316 when the tubes 304 are displaced to the formation 308. The telescoping
portion can provide a fluid conduit from the tubes 304 to the intemal flow path 314.
[0060] Hydrocarbon fluids can be produced by the formation 308 and received
by the tubes 304 through perforations 320. The tubes 304 can filter particulate
materials from the hydrocarbon fluids. The filtered hydrocarbon fluids flow through
opening 321 in the tubes 304 to the conduit formed by the telescoping portion of the
pistons 322. The filtered hydrocarbon fluids can flow from the conduit to the internal
flow path 314 through the opening 316. The filtered hydrocarbon fluids can be
produced at the surface through the internal flow path 314.
[0061] Screen assemblies according to various embodiments of the present
invention can be manufactured by a variety of processes. Figures 5-10 illustrate a
manufacturing process of a screen assembly according to one embodiment of the
present invention. Figure 5 illustrates a perspective view of a base pipe 402 that
defines an internal flow path 404. Framing members 406 are located exterior to the
base pipe 402. Figure 5 shows two framing members 406 that are spaced a selected
distance from each other. The distance between the two framing members 406 can be
selected based on a production interval length or on a desired length of swellable
material. Furthermore, manufacturing processes according to some embodiments can
utilize one framing member. The framing members 406 may be detachably coupled to
the base pipe 402. In other embodiments, the framing members 406 are permanently
coupled to the base pipe 402 or a base pipe that includes framing members integrally
formed with the base pipe is provided. The framing members 406 may be a rigid
material such as metal or composite polymer.
[0062] In Figure 6, casting members 408 are positioned exterior to the base pipe
402. For example, the casting members 408 can be positioned in grooves of the
framing members 406. The casting members 408 can be detachably coupled to the
framing members 406 by the grooves, clamps, or similar devices. In some
embodiments, a temporary bonding material couples the casting members 408 to the
framing members 406. The casting members 408 may be a rigid material such as
metal or composite polymer.
[0063] In Figure 7, support material 410 is positioned between each of the
casting members 408 and the base pipe 402. The support material 410 can be
positioned between each of the casting members 408 by locating the support material
410 on an exterior of at least part of the casting members 408. The support material
410 may be a low swelling or a non-swelling material that can retain its initial shape or
otherwise expand less than swellable material after contacting an activating fluid. An
example of support material 410 includes HNBR. In some embodiments, the support
material 410 is coupled temporarily to the casting members 408 by a temporary
bonding agent such as an epoxy.
[0064] In Figure 8, a swellable material 412 is positioned exterior to the base
pipe 402 and between the support material 410 and the base pipe 402. The swellable
material 412 may be a material that can expand in response to an activating fluid, such
as a hydrocarbon fluid, a gas, or water. The swellable material 412 can be processed
using heat and pressure to fonn grooves 414 in which the casting members 408 and
support material 410 are disposed.
[0065] In Figure 9, the framing members 406 and casting members 408 are
removed. For example, the casting members 408 can be removed from grooves 414
and detached from the framing members 406. The framing members 406 can be
detached from the base pipe 402. In some embodiments, the framing members 406
remain coupled to the base pipe 402 or are integrally formed with the base pipe 402,
which prevents removal. Removing the casting members 408 can leave support
material 410 disposed in each of the grooves 414 defined by the swellable material
412.
[0066] In Figure 10, tubes 416 are positioned in the grooves 414. Each of the
tubes 416 can include perforations 418 for receiving hydrocarbon fluid from a formation
and can define a collection flow path 420 for directing the hydrocarbon fluid to another
component, such as an inflow control device, filtration media, or discrimination
component, associated with the base pipe 402. The support material 410 is configured
to Isolate the perforations 418 from the swellable material 412 when the swellable
material 412 expands after contacting an activating fluid.
[0067] The base pipe 402, with the swellable material 412, support material 410,
and tubes 416, can be further processed to form a completed screen assembly. For
example, additional components, such as inflow control devices, filtration mediums, and
discrimination components, can be coupled to the base pipe 402 and the tubes 416 to
form a screen assembly capable of being disposed in a bore in a formation. In some
embodiments, the tubes 416 are filtration tubes that can filter particulate material from
hydrocarbons produced by the formation, othen/vise the tubes 416 are configured to not
require additional components to complete the screen assembly.
Illustrative swellable material compositions
[0068] Swellable material according to certain embodiments can be formed from
one or more materials that swell upon contact with an activating fluid. For example, the
swellable material may be a polymer that is capable of swelling to a size that is multiple
times its initial size upon contact with an activating fluid that stimulates the material to
expand. In some embodiments, the swellable material swells upon contact with an
activating fluid that is a hydrocarbon fluid or a gas. The hydrocarbon fluid Is absorbed
by the swellable material and the absorption causes the volume of the swellable
material to increase, thereby expanding radially. The swellable material may displace
the tubes and part of the outer surface of the swellable material contacts a formation
face in an open hole completion or a casing wall in a cased wellbore.
[0069] Some embodiments of the swellable material may be made from an
elastic polymer. Examples of elastic polymers include ethylene propylene diene
monomer (EPDM) rubber, styrene butadiene, natural rubber, ethylene propylene
monomer rubber, ethylene vinyl acetate rubber, hydrogenized acrylonitrile butadiene
rubber, acylonitrile butadiene rubber, isoprene rubber, chloroprene rubber and
polynorbornene. The swellable material may also include other materials dissolved in,
or in mechanical mixture, with the other materials that form the swellable material.
Examples of other materials include fibers of cellulose, polyvinyl chloride, methyl
methacrylate, acrylonitrile, ethylacetate, or other polymers.
[0070] In some embodiments, the swellable material is configured to expand
upon contact with an activating fluid that is water. For example, the swellable material
may be a water-swellable polymer such as a water-swellable elastomer or water-
swellable rubber. More specifically, the swellable material may be a water-swellable
hydrophobic polymer or water-swellable hydrophobic copolymer such as a water-
swellable hydrophobic porous copolymer. Other polymers that can be used to form the
swellable material include hydrophilic monomers and hydrophobically modified
hydrophilic monomers. Examples of suitable hydrophilic monomers include acrylamide,
2-acrylamido-2methyl propane sulfonic acid, N,N-dimethylacrylamide, vinyl pyrrolidone,
dimethylaminoethyl methacrylate, acrylic acid, trimethylammoniumethyl, methacrylate
chloride, dimethylaminopropylmethacrylamide, methacrylamide, and hydroxyethyl
acylate.
[0071] A variety of hydrophobically modified hydrophilic monomers can be
utilized in accordance with certain embodiments. Examples of hydophobically modified
hydrophilic monomers include alkyl acrylates, alkyl methacrylates, alkyl acrylamides,
alkyl methacrylamides (where alkyl radicals have from about 4 to about 22 carbon
atoms), alkyl dimethylammoniumethyl methacrylate chloride and alkyl
dimethylammoniumethyl methacrylate iodide (where the alkyl radicals have from about
4 to about 22 carbon atoms), alkyl dimethylammonium-propylmethacrylamide bromide,
alkyl dimethylammonium propylmethacrylamide chloride and alkyl dimethylammonium-
propylmethacrylamide iodide (where the alkyl groups have from about 4 to about 22
carbon atoms).
[0072] Polymers suitable in swellable material according to certain embodiments
can be prepared by polymerizing any one or more of the hydrophilic monomers with
any one or more of the hydrophobically modified hydrophilic monomers. The
polymerization reaction can be formed in various ways, an example of which is
described in U.S. Patent No. 6,476,169, which Is incorporated herein by reference.
These polymers may have estimated molecular weights in the range from about
100,000 to about 10,000,000, with a preferred range of 250,000 to about 3,000,000.
These polymers may also have mole ratios of the hydrophilic monomer(s) to the
hydrophobically modified hydrophilic monomer(s) in the range of from about 99.98:0.02
to about 90:10.
[0073] In some embodiments, the swellable material may be made from a salt
polymer such as polyacrylamide or modified crosslinked poly(meth)acrylate that tends
to attract water from salt water through osmosis. For example, when water that flows
from an area of low salt concentration (the formation water) to an area of high salt
concentration (a salt polymer), across a semi-permeable membrane (an interface
between the salt polymer and production fluids), the salt polymer allows water
molecules to pass, but prevents passage of dissolved salts.
[0074] The foregoing description of the embodiments, including illustrated
embodiments, of the invention has been presented only for the purpose of illustration
and description and is not Intended to be exhaustive or to limit the invention to the
precise forms disclosed. Numerous modifications, adaptations, and uses thereof will
be apparent to those skilled in the art without departing from the scope of this invention.
CLAIMS
1. A screen assembly capable of being disposed in a bore, the screen assembly
comprising: a swellable material disposed exterior to a base pipe; a tube disposed
exterior to the swellable material; and a support material disposed between the
swellable material and the tube, wherein, in response to contact with an activating fluid,
the swellable material is capable of expanding and displacing at least part of the tube
toward a surface of the bore, wherein the swellable material is configured to expand
more than the support material in response to the activating fluid.
2. A screen assembly according to claim 1, wherein the support material is a low-
swelling rubber compound.
3. A screen assembly according to claim 1 or 2, wherein the tube comprises a
plurality of perforations, wherein the support material is configured to isolate at least
one perforation of the plurality of perforations from the swellable material.
4. A screen assembly capable of being disposed in a bore, the screen assembly
comprising: a swellable material disposed exterior to a base pipe; a tube disposed
exterior to the swellable material, the tube comprising a plurality of perforations; and a
support material disposed between the swellable material and the tube, the support
material being capable of isolating at least one perforation of the plurality of
perforations from the swellable material, wherein, in response to contact with an
activating fluid, the swellable material is capable of expanding and displacing at least
part of the tube toward a surface of the bore.
5. A screen assembly according to claim 4, wherein the support material is a low-
swelling rubber compound configured to expand less than the swellable material.
6. A screen assembly according to any preceding claim, wherein the support
material is a non-swelling rubber compound configured to retain an initial shape when
the swellable material expands.
7. A screen assembly according to any preceding claim, wherein the swellable
material includes a groove, wherein the tube and the support material are disposed in
the groove.
8. A screen assembly according to any preceding claim, wherein the tube is a
filtration tube comprising a filter media for filtering particulate materials from
hydrocarbon fluids.
9. A screen assembly according to any preceding claim, wherein the support
material is hydrogenated nitrile butadiene rubber (HNBR).
10. A method of manufacturing a screen assembly capable of being disposed in a
bore, the method comprising: positioning a casting member exterior to a base pipe;
positioning a support material between the casting member and the base pipe;
positioning a swellable material between the support material and the base pipe, the
swellable material being configured to expand in response to an activating fluid;
processing the swellable material to form a groove in which the casting member and
the support material are disposed; removing the casting member from the groove; and
positioning a tube in the groove.
11. A method of manufacturing according to claim 10, wherein the tube comprises a
plurality of perforations, wherein the support material Is capable of isolating the plurality
of perforations from the swellable material when the swellable material expands.
12. A method of manufacturing according to claim 10 or 11, wherein the support
material is a low-swelling rubber compound configured to expand less than the
swellable material.
13. A method of manufacturing according to claim 10 or 11, wherein the support
material is a non-swelling rubber compound configured to retain an initial shape when
the swellable material expands.
14. A method of manufacturing according to any one of claims 10 to 13, wherein the
support material Is hydrogenated nitrile butadiene rubber (HNBR).
15. A method of manufacturing according to any one of claims 10 to 14, further
comprising: positioning a framing member exterior to the base pipe, wherein positioning
the casting member exterior to the base pipe comprises coupling the casting member
to the framing member.

Screen assemblies capable of being disposed in a wellbore for hydrocarbon fluid
production are described. The screen assemblies can support tubes for receiving
hydrocarbon fluid and reduce or eliminate plugging of the tubes by swellable material.
A screen assembly may include a support material between a tube and swellable
material located exterior to a base pipe. The tube may include perforations and can
receive and direct hydrocarbon fluids from the formation. The swellable material can
expand after contact with an activating fluid and can displace the tube toward a surface
of the bore. The swellable material can expand more than the support material and the
support material can reduce or prevent plugging of the perforations by the swellable
material expanding.