POROUS MEDIUM SCREEN
Technical Field of the Invention
[0001] The present invention relates generally to devices for sand
control during production of fluid from a wellbore in a subterranean formation
and, more particularly (although not necessarily exclusively), to porous
medium screens that can filter particulate material from formation fluids in
producing wells.
Background
[0002] Particulate materials, such as sand, may be produced during the
production of hydrocarbons from a well system traversing a subterranean
formation. A well system can include devices and procedures for sand
control. The production of sand can restrict productivity, erode components of
the well system, impede wellbore access, interfere with the operation of
downhole equipment, and present disposal difficulties. Sand control can
include preventing sand, silt, or other particles from a subterranean formation
from entering a wellbore or near-wellbore area of a well system. Sand control
can reduce or prevent the migration of sand and other particles into the near
wellbore area that may restrict production of fluids from the subterranean
formation. In some subterranean formations, sand control can help maintain
the structure of a reservoir of fluid around the wellbore in the subterranean
formation.
[0003] It is desirable to prevent the production of particulate materials
from a well that traverses a hydrocarbon bearing subterranean formation.
Summary
[0004] In some embodiments, a porous medium screen is provided that
can be disposed in a wellbore through a fluid-producing formation. The
porous medium screen can include a porous medium, such as a foam, and a
retaining structure. The porous medium can be a material that includes one
or more pores. The one or more pores can be adapted to allow a fluid to flow
through the porous medium and to prevent one or more particles from flowing
through the porous medium. The retaining structure can be adapted to retain
the porous medium in a position circumferentially surrounding a section of a
tubing string. The retaining structure can be further adapted to prevent radial
expansion of the porous medium or axial expansion of the porous medium.
[0005] These illustrative aspects and features 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
[0006] Figure 1 is a schematic illustration of a well system having a
porous medium screen according to one embodiment of the present
invention.
[0007] Figure 2 is a partial perspective view of a section of a tubing
string having a porous medium screen according to one embodiment of the
present invention.
[0008] Figure 3 is a longitudinal cross-sectional view of a section of a
tubing string having a porous medium screen according to one embodiment of
the present invention.
[0009] Figure 4 is a lateral cross-sectional view of a section of a tubing
string having a porous medium screen according to one embodiment of the
present invention.
[001 0] Figure 5 is a perspective view of a section of a tubing string
having a porous medium within openings of the section of the tubing string
according to one embodiment of the present invention.
[001 1] Figure 6 is a longitudinal cross-sectional view of a section of a
tubing string having a porous medium within openings of the section of the
tubing string according to one embodiment of the present invention.
[001 2] Figure 7 is a lateral cross-sectional view of a section of a tubing
string having a porous medium within openings of the section of the tubing
string according to one embodiment of the present invention.
[001 3] Figure 8 depicts carbon foam that can be used as a porous
medium for a porous medium screen according to one embodiment of the
present invention.
[0014] Figure 9 depicts a silicon carbide foam that can be used as a
porous medium for a porous medium screen according to one embodiment of
the present invention.
Detailed Description
[001 5] Certain aspects and embodiments of the present invention are
directed to a porous medium screen that can be disposed in a wellbore
through a fluid-producing formation. The porous medium screen can include
a porous medium, such as a metallic foam or other foam. The porous
medium can include pores of a sufficient diameter to prevent or obstruct
particles in production fluid from a subterranean formation from entering a
section of a tubing string in a well system and to allow the production fluid to
flow into the tubing string. A retaining structure, such as a rigid shroud, can
prevent the porous medium from expanding. The use of a porous medium
constrained by a retaining structure preventing expansion of the porous
medium can provide a simpler and less costly sand control solution as
compared to, for example, expandable sand screen assemblies using a series
of metallic mesh filtration layers formed from impermeable materials.
[001 6] The porous medium screen can include a porous medium with
one or more pores. The porous medium can be, for example, a cellular
structure that includes a continuous material having a series of pores. The
continuous material can provide a frame in which pores can be located. A
pore can be an empty space within the continuous material. Examples of the
porous medium can include, but are not limited to, a solid material or a foam.
The pores can interconnect such that the pores form a series of channels
through the porous medium such that fluid or other materials can move
through the material. The series of channels formed by the pores and the
frame provided by the continuous material can be continuous so as to form
two interpenetrating continua.
[001 7] The pores of the porous medium can be adapted to allow a fluid
to flow through the porous medium and to prevent particles from flowing
through the porous medium. Examples of a porous medium can include (but
are not limited to) a carbon foam, a silicone foam, a silicone carbide foam, a
metal foam, a polyester foam, a polyurethane foam, an epoxy having
dissolvable porous medium, a silicon carbon foam, etc.
[001 8] The porosity of a porous medium can be varied based on the
expected particle size of a particle to be screened and a viscosity of a
production fluid in a given subterranean formation. The term "porosity" can
refer to a measurement of the pores in a material expressed as a fraction of
the volume of empty spaces over the total volume. The average size of the
pores in a porous medium can also be varied. One example of a porous
medium is a metal foam with a porosity wherein 75-95% of the volume of the
metal foam includes empty spaces and with an average pore size of 5-10
millimeters. Another example of a porous medium is a carbon foam with a
porosity wherein 3% of the volume of the metal foam includes empty spaces
and with an average pore size of 0.1 millimeters.
[001 9] The viscosity of the production fluid can be the resistance of the
production fluid to movement or flow. For example, heavy crude oil may have
a high viscosity greater than ten centipoise. A porous medium can be
selected and/or manufactured to have a porosity and an average pore size
such that the viscosity of the production fluid produced from a subterranean
formation does not prevent the production fluid from flowing through the
porous medium. A porous medium can be selected and/or manufactured to
have a porosity and an average pore size such that particles in a production
fluid are prevented from flowing through the porous medium. The porosity
and average pore size of the porous medium can be varied based on the
characteristics of the subterranean formation in which the porous medium
screen may be deployed, such as the average diameter of sand particles
encountered in the formation.
[0020] The porous medium screen can be configured to be coupled to a
section of a tubing string. The porous medium screen can be installed with
the section of the tubing string in a well system.
[0021] The porous medium screen can include a retaining structure.
The retaining structure can retain the porous medium in a position
circumferentially surrounding a section of a tubing string. The retaining
structure can prevent the porous medium from expanding in one or more of a
radial direction or an axial direction. The porous medium expanding in a
radial direction can include the porous medium expanding in a direction from
an outer diameter of a tubing string to the subterranean formation. The
porous medium expanding in an axial direction can include the porous
medium expanding in a direction substantially parallel to the orientation of a
tubing string in a wellbore. The retaining structure can be configured to be
attached or otherwise coupled to a section of a tubing string such that the
retaining structure remains attached to the section of the tubing string
disposed in a wellbore through the fluid-producing formation. In some
embodiments, attaching or otherwise coupling the retaining structure to the
section of a tubing string can prevent the retaining structure from being
removed from the porous medium screen, thereby permanently preventing
the porous medium from expanding.
[0022] The retaining structure can include a shroud. The shroud can be
adapted to circumferentially surround the porous medium. The shroud can
include a series of strands adapted to be coupled to one another. Each of the
strands can be formed from any suitable non-permeable and rigid or semi¬
rigid material, such as a metal. The strands of the shroud can be spaced so
as to allow fluids and particles to pass through the spaces between the
strands. The shroud can prevent the porous medium from expanding in a
radial direction. The shroud can protect the porous medium during
deployment. The shroud can also protect the porous medium coupled to a
tubing section being moved or otherwise manipulated in a wellbore system.
Protecting the porous medium can include preventing damage to the porous
medium during insertion or manipulation of a section of a tubing string into a
wellbore. The shroud can be a solid material having openings allowing fluid
and particles to flow through the shroud.
[0023] The retaining structure can also include one or more stoppers. A
stopper, such as a ring, can be adapted to circumferentially surround a
section of a tubing string. The stopper can be formed using any suitable
material, such as a non-permeable and rigid or semi-rigid material. Examples
of suitable materials include, but are not limited to, rubber, metal, plastic, etc.
A stopper can be placed at one or more edges of a section of the porous
medium to prevent the movement of the porous medium along the tubing
string. The stopper can prevent the porous medium from expanding in an
axial direction.
[0024] These illustrative examples are given to introduce the reader to
the general subject matter discussed here and are not intended to limit the
scope of the disclosed concepts. The following sections describe various
additional embodiments and examples with reference to the drawings in
which like numerals indicate like elements, and directional descriptions are
used to describe the illustrative embodiments but, like the illustrative
embodiments, should not be used to limit the present invention.
[0025] Figure 1 schematically depicts a well system 100 having a tubing
string 112 with porous medium screens 116a-d according to certain
embodiments of the present invention. The well system 100 includes a bore
that is a wellbore 102 extending through various earth strata. The wellbore
102 has a substantially vertical section 104 and a substantially horizontal
section 106. The substantially vertical section 104 and the substantially
horizontal section 106 may include a casing string 108 cemented at an upper
portion of the substantially vertical section 104. The substantially horizontal
section 106 extends through a hydrocarbon bearing subterranean formation
110.
[0026] The tubing string 112 within wellbore 102 extends from the
surface to the subterranean formation 110. The tubing string can include one
or more tubing sections 114a-d. The tubing string 112 can provide a conduit
for formation fluids, such as production fluids produced from the subterranean
formation 110, to travel from the substantially horizontal section 106 to the
surface. Pressure from a bore in a subterranean formation can cause
formation fluids, including production fluids such as gas or petroleum, to flow
to the surface.
[0027] The well system 100 can also include one or more porous
medium screens 116a-d. Each of the porous medium screens 116a-d can be
coupled to a respective tubing section 114a-d of the tubing string 112 at a
horizontal section 106. The porous medium screens 116a-d can filter
particulate materials of a predetermined size from the production fluid of the
subterranean formation 110 as the production fluid flows into the tubing
sections 114a-d.
[0028] Although Figure 1 depicts the porous medium screens 116a-d
positioned in the substantially horizontal section 106, a porous medium
screen can be located, additionally or alternatively, in the substantially vertical
section 104. In some embodiments, porous medium screens can be
disposed in simpler wellbores, such as wellbores having only a substantially
vertical section. Porous medium screens can be disposed in openhole
environments, such as is depicted in Figure 1, or in cased wells.
[0029] Although Figure 1 depicts four porous medium screens 116a-d
positioned in the tubing string 112, any number of porous medium screens
can be used.
[0030] Figure 2 is a partial perspective view of a section of a tubing
section 114 of a tubing string 112 having a porous medium screen 116. The
partial perspective view of the tubing section 114 is partially cut away to
depict a first layer of the porous medium screen 116 that includes a porous
medium 206 circumferentially surrounding a body 202 of the tubing section
114 and a second layer of the porous medium screen 116 that includes a
shroud 210 of a retaining structure circumferentially surrounding the porous
medium 206.
[0031] The tubing section 114 can include one or more openings 202 in
the body 204 of the tubing section 114. Production fluid produced from the
subterranean formation 110 can enter the body 204 via the openings 202.
Examples of the openings 202 can include (but are not limited to) perforations
or slots in the body 204 of the tubing section 114.
[0032] The production fluid can be filtered by the porous medium screen
116. Although Figure 2 depicts the openings 202 as exposed, a tubing
section 114 can be deployed with the porous medium screen 116
circumferentially surrounding the tubing section 114 such that the porous
medium screen 116 is positioned between the subterranean formation 110
and the openings 202 of the body 204 of the tubing section 114.
[0033] The porous medium screen 116 can include the porous medium
206 and a retaining structure. The porous medium 206 can filter the
production fluid. The retaining structure can include any device, structure, or
group of devices and/or structures adapted to couple the porous medium 206
to the tubing section 114 or to otherwise retain the porous medium 206 in a
position between the openings 202 and the subterranean formation 110. As
depicted in Figure 2, an example of a retaining structure can include a shroud
210 and a stopper 212. In some embodiments, the retaining structure can be
configured to be attached or otherwise coupled to the tubing section 114 such
that the retaining structure, such as the shroud 210 and the stopper 212,
cannot be removed from the tubing section 114 installed in a well system 100.
[0034] The porous medium 206 can be any suitable medium having
pores 208. The porous medium 206 can be, for example, a cellular structure
that includes a solid material containing a series of interconnected pores
forming a series of channels through the porous medium 206. The porous
medium 206 can be manufactured or otherwise such that the pores 208 are
adapted to allow a fluid to flow through the porous medium 206 and to prevent
particles from moving through the porous medium 206. Examples of a porous
medium 206 can include (but are not limited to) a carbon foam, a silicone
foam, a metal foam, a polyester foam, a polyurethane foam, an epoxy having
dissolvable porous medium 206, a silicon carbon foam, etc.
[0035] The porosity and average pore size of a porous medium 206 can
be varied based on the particle size of particulate material from the
subterranean formation 110. The porous medium 206 can also be selected
and/or manufactured such that the porosity and average pore size of the
pores 208 prevent or obstruct particles in the production fluid from moving
through the porous medium 206. For example, a production fluid from a
subterranean formation may include particles, such as sand particles, having
a diameter between 0.0625 millimeters and 2 millimeters. A suitable porous
medium 206 can be selected and/or manufactured such that the porous
medium 206 has pores 208 with a pore size of less than 0.0625 millimeters in
diameter, such as .0500 millimeters. The porous medium 206 can also be
selected or manufactures such that the pores 208 have a porosity and
average pore size allowing fluid with the viscosity of the production fluid from
the subterranean formation 110 to flow through the porous medium 206.
[0036] The shroud 210 can protect the porous medium 206 during
deployment of the tubing section 114 and can prevent the porous medium
206 from expanding in a radial direction. The shroud 210 can also protect the
porous medium 206 coupled to a tubing section 114 being moved or
otherwise manipulated in a wellbore system. Protecting the porous medium
206 can include preventing damage to the porous medium during insertion of
the tubing section 114 into the wellbore 102. For example, a tubing section
114 being deployed into a wellbore 102 can encounter ledges or other
restrictions in the subterranean formation 110. The shroud 210 can prevent
the ledges or other restrictions from contacting the porous medium 206 and
damaging the porous medium 206. The shroud 210 can be a solid material
having openings allowing fluid and particles to flow through the shroud 210.
For example, the shroud 210 can include a net structure manufactured from a
metal or other suitable material. The shroud 210 can also prevent radial
expansion of the porous medium 206 coupled to a tubing section 114 installed
in an operational well system 100.
[0037] The retaining structure can also include a stopper 212. The
stopper 212 can be adapted to circumferentially surround the tubing section
114. The stopper 212 can prevent the porous medium 206 from expanding in
an direction. The stopper 212 can be, for example, a ring. The stopper 212
can be formed using any suitable material, such as a non-permeable and rigid
or semi-rigid material. Examples of suitable materials include, but are not
limited to, rubber, metal, plastic, etc. Although the partial perspective view of
Figure 2 depicts a single stopper 212 at a single edge of the porous medium
206, a stopper can be positioned at each edge of the porous medium 206.
[0038] Although Figure 2 depicts a porous medium screen 116 having a
retaining structure with a shroud 210 and a stopper 212, other embodiments
can be used. In some embodiments, a porous medium 206 can be
sufficiently durable and rigid that a shroud 210 for protecting the porous
medium 206 and preventing radial expansion of the porous medium can be
omitted. In other embodiments, a porous medium 206 can be coupled to the
tubing section 114 via adhesion, such as using an adhesive material or via an
adhesive property of the porous medium itself. In other embodiments, a
porous medium 206 coupled to the tubing section 114 via adhesion can omit
either or both of the shroud 210 or the stopper 212.
[0039] Figure 3 depicts a longitudinal cross-sectional view of the tubing
section 114 having the porous medium screen 116 taken along the line 3-3' of
Figure 2 . The direction of fluid flow from subterranean formation 110 is
depicted by arrows 302a, 302b. The retaining structure of the porous medium
screen 116 can include the stoppers 212a, 212b. Figure 4 depicts a lateral
cross-sectional view of the tubing section 114 having the porous medium
screen 116 taken along the line 4-4' of Figure 2 .
[0040] Production fluid can flow from the subterranean formation 110
through the pores 208 of the porous medium 206. Particles in the production
fluid can be prevented from passing through the porous medium, thereby
filtering such particles from the production fluid. Production fluid can exit the
pores of the porous medium 206 and enter the body 204 of the tubing section
114 via the openings 202.
[0041] Although the pores 208 of the porous medium screen 116 are
depicted in Figure 3 as channels from a first side of the porous medium 206 to
another side of the porous medium 206, any series of interconnecting pores
forming a series of channels through the porous medium 206 can be used.
[0042] Although Figures 2-4 depict a porous medium 206
circumferentially surrounding a tubing section 114, other implementations are
possible. For example, Figures 5-7 depict a tubing section 114' of a tubing
string 112 having a porous medium 206 within openings 202 of the tubing
section 114'. Figure 5 is a perspective view of the tubing section 114'. Figure
6 is a longitudinal cross-sectional view of the tubing section 114' taken along
the line 6-6' of Figure 5 . Figure 7 is a lateral cross-sectional view of the
tubing section 114' taken along the line 7-7' of Figure 5 .
[0043] As depicted in Figures 5-7, the porous medium 206 is located
within each of the openings 202 in the body 204 of the tubing section 114.'
The tubing section 114' can also include a shroud 210 circumferentially
surrounding the tubing section 114.' The flow of fluid from the subterranean
formation 110 can be similar to that depicted in Figures 3-4. The shroud 210
depicted in Figures 5-7 can protect the porous medium 206. In other
embodiments, the shroud 210 can be omitted.
[0044] Figures 8 and 9 depict examples of porous foams that can be
used in a porous medium screen, such as a carbon foam depicted in Figure 8
and a silicon carbide foam having pores depicted in Figure 9 Although
Figures 8 and 9 depict examples of porous media, any porous medium having
a suitable porosity and/or pore size can be used.
[0045] 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 porous medium screen configured for being disposed in a wellbore
through a fluid-producing formation, the porous medium screen comprising:
a porous medium comprising a foam having one or more pores
adapted to allow a fluid to flow through the porous medium and to prevent one
or more particles from flowing through the porous medium; and
a retaining structure adapted to allow the fluid to flow from the fluidproducing
formation to the porous medium and further adapted to retain the
porous medium in a position circumferentially surrounding a section of a
tubing string disposed in the fluid-producing formation and to prevent
expansion of the porous medium.
2 . The porous medium screen of claim 1, wherein the foam comprises a
continuous material and wherein each of the one or more pores comprises
empty space within the continuous material.
3 . The porous medium screen of claim 1, wherein the porous medium
comprises a carbon foam.
4 . The porous medium screen of claim 1, wherein the porous medium
comprises a silicone foam.
5 . The porous medium screen of claim 1, wherein the porous medium
comprises a metal foam.
6 . The porous medium screen of claim 1, wherein the porous medium
comprises a polyurethane foam.
7 . The porous medium screen of claim 1, wherein the retaining structure
comprises a shroud adapted to circumferentially surround the porous medium
and to prevent radial expansion of the porous medium, the shroud comprising
a plurality of strands, each of the plurality of strands adapted to be coupled to
at least another one of the plurality of strands, each of the plurality of strands
comprising a non-permeable rigid material.
8 . The porous medium screen of claim 7, wherein the retaining structure
further comprises a stopper at one or more edges of the porous medium, the
stopper comprising an additional non-permeable rigid material, the stopper
adapted to prevent axial expansion of the porous medium.
9 . The porous medium screen of claim 8, wherein the stopper is adapted
to circumferentially surround the section of the tubing string.
10. The porous medium screen of claim 1, wherein the porous medium
screen is configured to be coupled to the section of the tubing string.
11. A production tubing system comprising:
a section of a tubing string configured to be disposed in a wellbore
through a fluid-producing formation; and
a porous medium screen configured to be coupled to the section of the
tubing string, the porous medium screen comprising:
a porous medium, the porous medium having one or more pores
adapted to allow a fluid to flow through the porous medium and to prevent one
or more particles from flowing through the porous medium, and
a retaining structure adapted to allow the fluid to flow from the
fluid-producing formation to the porous medium and further adapted to retain
the porous medium in a position circumferentially surrounding the section of
the tubing string and to prevent expansion of the porous medium.
12. The production tubing system of claim 11, wherein the foam comprises
a continuous material and wherein each of the one or more pores comprises
empty space within the continuous material.
13. The production tubing system of claim 11, wherein the retaining
structure of the porous medium screen comprises a shroud adapted to
circumferentially surround the porous medium and to prevent radial expansion
of the porous medium, the shroud comprising a plurality of strands, each of
the plurality of strands adapted to be coupled to at least another one of the
plurality of strands, each of the plurality of strands comprising a nonpermeable
material.
14. The production tubing system of claim 13, wherein the retaining
structure of the porous medium screen further comprises a stopper at one or
more edges of the porous medium, the stopper comprising a non-permeable
rigid material, the stopper adapted to circumferentially surround the section of
the tubing string and to prevent axial expansion of the porous medium.
15. The production tubing system of claim 14, wherein the stopper
comprises a ring adapted to circumferentially surround the section of the
tubing string.
16. The production tubing system of claim 11, wherein the porous medium
comprises a carbon foam.
17. The production tubing system of claim 11, wherein the porous medium
comprises a silicone foam.
18. The production tubing system of claim 11, wherein the porous medium
comprises a metal foam.
19. The production tubing system of claim 11, wherein the porous medium
comprises at least one of a polyester foam and a polyurethane foam.
20. A porous medium screen configured for being disposed in a wellbore
through a fluid-producing formation, the porous medium screen comprising:
a porous medium comprising a foam having one or more pores
adapted to allow a fluid to flow through the porous medium and to prevent one
or more particles from flowing through the porous medium; and
a retaining structure adapted to allow the fluid to flow from the fluidproducing
formation to the porous medium and further adapted to retain the
porous medium in a position circumferentially surrounding a section of a
tubing string disposed in the wellbore through the fluid-producing formation,
wherein the retaining structure comprises:
a shroud adapted to circumferentially surround the porous
medium and to prevent radial expansion of the porous medium, the shroud
comprising a plurality of strands, each of the plurality of strands adapted to be
coupled to at least another one of the plurality of strands, each of the plurality
of strands comprising a non-permeable rigid material, and
a stopper at one or more edges of the porous medium, the
stopper comprising an additional non-permeable rigid material, the stopper
adapted to circumferentially surround the section of the tubing string and to
prevent axial expansion of the porous medium.