SAND CONTROL SCREEN ASSEMBLY AND METHOD FOR USE OF SAME
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates, in general, to controlling the production of particulate materials
from a subterranean formation and, in particular, to a sand control screen assembly having
radially extendable filter members that are operable to contact the formation upon actuation.
BACKGROUND OF THE INVENTION
[0002] Without limiting the scope of the present invention, its background is described with
reference to the production of hydrocarbons through a wellbore traversing an unconsolidated
or loosely consolidated formation, as an example.
[0003] It is well known in the subterranean well drilling and completion art that particulate
materials such as sand may be produced during the production of hydrocarbons from a well
traversing an unconsolidated or loosely consolidated subterranean formation. Numerous
problems may occur as a result of the production of such particulate materials. For example,
the particulate materials cause abrasive wear to components within the well, such as tubing,
flow control devices and safety devices. In addition, the particulate materials may partially or
fully clog the well creating the need for an expensive workover. Also, if the particulate
materials are produced to the surface, they must be removed from the hydrocarbon fluids by
processing equipment at the surface.
[0004] One method for preventing the production of such particulate materials is gravel
packing the well adjacent the unconsolidated or loosely consolidated production interval. In
a typical gravel pack completion, a sand control screen is lowered into the wellbore on a
work string to a position proximate the desired production interval. A fluid slurry including a
liquid carrier and a particulate material, such as gravel, is then pumped down the work string
and into the well annulus formed between the sand control screen and the perforated well
casing or open hole production zone.
[0005] The liquid carrier either flows into the formation, returns to the surface by flowing
through the sand control screen or both. In either case, the gravel is deposited around the
sand control screen to form a gravel pack, which is highly permeable to the flow of
hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids.
As such, gravel packs can successfully prevent the problems associated with the production
of particulate materials from the formation.
[0006] It has been found, however, that a complete gravel pack of the desired production
interval is difficult to achieve particularly in extended or deviated wellbores including
wellbores having long, horizontal production intervals. These incomplete packs are
commonly a result of the liquid carrier entering a permeable portion of the production
interval causing the gravel to dehydrate and form a sand bridge in the annulus. Thereafter,
the sand bridge prevents the slurry from flowing to the remainder of the annulus which, in
turn, prevents the placement of sufficient gravel in the remainder of the production interval.
[0007] In addition, it has been found that gravel packing is not feasible in certain open hole
completions. Attempts have been made to use expandable metal sand control screens in such
open hole completions. These expandable metal sand control screens are typically installed
in the wellbore then radially expanded using a hydraulic swage or cone that passes through
the interior of the screen or other metal forming techniques. In addition to filtering
particulate materials out of the formation fluids, one benefit of these expandable sand control
screens is the radial support they provide to the formation which helps prevent formation
collapse. It has been found, however, that conventional expandable sand control screens do
not contact the wall of the wellbore along their entire length as the wellbore profile is not
uniform. More specifically, due to the process of drilling the wellbore and heterogeneity of
the downhole strata, washouts or other irregularities commonly occur which result in certain
locations within the wellbore having larger diameters than other areas or having non circular
cross sections. Thus, when the expandable sand control screens are expanded, voids are
created between the expandable sand control screens and the irregular areas of the wellbore,
which has resulted in incomplete contact between the expandable sand control screens and
the wellbore. In addition, with certain conventional expandable sand control screens, the
threaded connections are not expandable which creates a very complex profile, at least a
portion of which does not contact the wellbore. Further, when conventional expandable sand
control screens are expanded, the radial strength of the expanded screens is drastically
reduced resulting in little, if any, radial support to the borehole.
[0008] Therefore, a need has arisen for a sand control screen assembly that prevents the
production of particulate materials from a well that traverses a hydrocarbon bearing
subterranean formation without the need for performing a gravel packing operation. A need
has also arisen for such a sand control screen assembly that provides radial support to the
formation without the need for expanding metal tubulars. Further, a need has arisen for such
a sand control screen assembly that is suitable for operation in long, horizontal, open hole
completions.
SUMMARY OF THE INVENTION
[0009] The present invention disclosed herein comprises a sand control screen assembly that
prevents the production of particulate materials from a well that traverses a hydrocarbon
bearing subterranean formation or operates as an injection well. The sand control screen
assembly of the present invention achieves this result without the need for performing a
gravel packing operation. In addition, the sand control screen assembly of the present
invention interventionlessly provides radial support to the formation without the need for
expanding metal tubulars. Further, the sand control screen assembly of the present invention
is suitable for operation in open hole completions in long, horizontal production intervals.
[0010] In one aspect, the present invention is directed to a sand control screen assembly that
is operable to be positioned within a wellbore. The sand control screen assembly includes a
base pipe having at least one opening in a sidewall portion thereof and an internal flow path.
A plurality of radially extendable filter members are each operably associated with at least
one of the openings of the base pipe. The radially extendable filter members have a
circumferential dimension that is less than a longitudinal dimension thereof. The radially
extendable filter members also have a radially retracted running configuration and a radially
extended operating configuration, in which, the radially extendable filter members are
preferably in close proximity to or contact with the wellbore.
[0011] In one embodiment, a swellable material layer is disposed between the base pipe and
at least a portion of the radially extendable filter members such that, in response to contact
with an activating fluid, radial expansion of the swellable material layer causes the radially
extendable filter members to operate from their running configuration to their operating
configuration. In this embodiment, the activating fluid may be a hydrocarbon fluid, water,
gas or the like.
[0012] In one embodiment, the radially extendable filter members include a cylinder that is
coupled to the base pipe and a radially telescoping piston slidably received within the
cylinder. In certain embodiments, the radially extendable filter members include a filter
retainer and filter medium. In other embodiments, the radially extendable filter members
include a perforated tubular. The filter medium associated with the radially extendable filter
members may be any one or more of a single layer mesh screen, a multiple layer mesh
screen, a wire wrapped screen, a prepack screen, a ceramic screen, metallic or ceramic balls
or beads the are sintered or unsintered, a fluid porous, particulate resistant sintered wire mesh
screen and a fluid porous, particulate resistant diffusion bonded wire mesh screen.
[0013] In one embodiment, the ratio between the circumferential dimension and the
longitudinal dimension of the radially extendable filter members is at least 1 to 2. In another
embodiment, the ratio between the circumferential dimension and the longitudinal dimension
of the radially extendable filter members is between about 1 to 2 and about 1 to 10. In a
further embodiment, the ratio between the circumferential dimension and the longitudinal
dimension of the radially extendable filter members is between about 1 to 10 and about 1 to
30.
[0014] In some embodiments, a fluid flow control device is operably associated with each of
the radially extendable filter members. In other embodiments, a fluid flow control device
may be operably associated with a plurality of the radially extendable filter members.
[0015] In another aspect, the present invention is directed to a sand control screen assembly
that is operable to be positioned within a wellbore. The sand control screen assembly
includes a base pipe having a plurality of openings in a sidewall portion thereof and an
internal flow path. A plurality of radially extendable filter members are each operably
associated with at least one of the openings of the base pipe. The radially extendable filter
members have a circumferential dimension that is less than a longitudinal dimension thereof.
A swellable material layer is disposed exteriorly of the base pipe, such that, in response to
contact with an activating fluid, radial expansion of the swellable material layer causes at
least a portion of the radially extendable filter members to be displaced toward and preferably
in close proximity or contact with a surface of the wellbore.
[0016] In a further aspect, the present invention is directed to a method of installing a sand
control screen assembly in a wellbore. The method includes running the sand control screen
assembly to a target location within the wellbore, the sand control screen assembly including
a plurality of radially extendable filter members each of which is operably associated with at
least one opening of a base pipe, the radially extendable filter members having a
circumferential dimension that is less than a longitudinal dimension thereof and operating the
radially extendable filter members from a radially retracted running configuration to a
radially extended operating configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a more complete understanding of the features and advantages of the present
invention, reference is now made to the detailed description of the invention along with the
accompanying figures in which corresponding numerals in the different figures refer to
corresponding parts and in which:
[0018] Figure 1A is a schematic illustration of a well system operating a plurality of sand
control screen assemblies in their running configuration according to an embodiment of the
present invention;
[0019] Figure 1B is a schematic illustration of a well system operating a plurality of sand
control screen assemblies in their operating configuration according to an embodiment of the
present invention;
[0020] Figure 2A is a cross sectional view taken along line 2A-2A of a sand control screen
assembly of figure 1A in a running configuration according to an embodiment of the present
invention;
[0021] Figure 2B is a cross sectional view taken along line 2B-2B of a sand control screen
assembly of figure 1B in an operating configuration according to an embodiment of the
present invention;
[0022] Figure 3A is a cross sectional of a sand control screen assembly in a running
configuration according to an embodiment of the present invention;
[0023] Figure 3B is a cross sectional of a sand control screen assembly in an operating
configuration according to an embodiment of the present invention;
[0024] Figure 4A is a side view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0025] Figure 4B is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0026] Figure 4C is a top view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0027] Figure 5A is a top view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0028] Figure 5B is a top view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0029] Figure 6A is a side view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0030] Figure 6B is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0031] Figure 6C is a side view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0032] Figure 6D is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0033] Figure 7A is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0034] Figure 7B is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0035] Figure 7C is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0036] Figure 7D is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0037] Figure 8A is a side view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0038] Figure 8B is a front view of a radially extendable filter member for use in a sand
control screen assembly according to an embodiment of the present invention;
[0039] Figure 9A is a cross sectional view of a sand control screen assembly in a running
configuration according to an embodiment of the present invention;
[0040] Figure 9B is a cross sectional view of a sand control screen assembly in an operating
configuration according to an embodiment of the present invention;
[0041] Figure 10A is a cross sectional view of a sand control screen assembly in a running
configuration according to an embodiment of the present invention;
[0042] Figure 10B is a cross sectional view of a sand control screen assembly in an operating
configuration according to an embodiment of the present invention;
[0043] Figure 11A is a cross sectional view of a sand control screen assembly in a running
configuration according to an embodiment of the present invention; and
[0044] Figure 11B is a cross sectional view of a sand control screen assembly in an operating
configuration according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0045] While the making and using of various embodiments of the present invention are
discussed in detail below, it should be appreciated that the present invention provides many
applicable inventive concepts which can be embodied in a wide variety of specific contexts.
The specific embodiments discussed herein are merely illustrative of specific ways to make
and use the invention, and do not delimit the scope of the present invention.
[0046] Referring initially to figure 1A, therein is depicted a well system including a plurality
of sand control screen assemblies embodying principles of the present invention that is
schematically illustrated and generally designated 10. In the illustrated embodiment, a
wellbore 12 extends through the various earth strata. Wellbore 12 has a substantially vertical
section 14, the upper portion of which has installed therein a casing string 16 that is cemented
within wellbore 12. Wellbore 12 also has a substantially horizontal section 18 that extends
through a hydrocarbon bearing subterranean formation 20. As illustrated, substantially
horizontal section 18 of wellbore 12 is open hole.
[0047] Positioned within wellbore 12 and extending from the surface is a tubing string 22.
Tubing string 22 provides a conduit for formation fluids to travel from formation 20 to the
surface. Positioned within tubing string 22 is a plurality of sand control screen assemblies
24. The sand control screen assemblies 24 are shown in a running or unextended
configuration.
[0048] Referring also to figure 1B, therein is depicted the well system of figure 1A with sand
control screen assemblies 24 in their operating or radially expanded configuration. As
explained in greater detail below, each of the depicted sand control screen assemblies 24 has
a base pipe, a plurality of radially extendable filter members and a swellable material layer.
In general, the swellable material layer is disposed exteriorly around the base pipe and the
radially extendable filter members are disposed externally of the swellable material layer. In
this configuration, when sand control screen assemblies 24 come in contact with an activating
fluid, such as a hydrocarbon fluid, water or a gas, the swellable material layer of each sand
control screen assembly 24 radially expands which in turn causes the radially extendable
filter members of sand control screen assemblies 24 to contact the surface of wellbore 12.
[0049] Even though figures 1A-1B, depict tubing string 22 as including only sand control
screen assemblies 24, those skilled in the art will recognize that tubing string 22 may include
any number of other tools and systems such as fluid flow control devices, communication
systems, safety systems and the like. Also, tubing string 22 may be divided into a plurality of
intervals using zonal isolation devices such as packers. Similar to the swellable material in
sand control screen assemblies 24, these zonal isolation devices may be made from materials
that swell upon contact with a fluid, such as an inorganic or organic fluid. Some exemplary
fluids that may cause the zonal isolation devices to swell and isolate include water, gas and
hydrocarbons.
[0050] In addition, even though figures 1A-1B depict the sand control screen assemblies of
the present invention in a horizontal section of the wellbore, it should be understood by those
skilled in the art that the sand control screen assemblies of the present invention are equally
well suited for use in deviated or vertical wellbores. Accordingly, it should be understood by
those skilled in the art that the use of directional terms such as above, below, upper, lower,
upward, downward and the like are used in relation to the illustrative embodiments as they
are depicted in the figures, the upward direction being toward the top of the corresponding
figure and the downward direction being toward the bottom of the corresponding figure.
Likewise, even though figures 1A-1B depict the sand control screen assemblies of the
present invention in a wellbore having a single borehole, it should be understood by those
skilled in the art that the sand control screen assemblies of the present invention are equally
well suited for use in multilateral wellbores having a main wellbore and a plurality of branch
wellbores.
[0051] Referring to figures 2A and 3A, therein are depicted cross sectional views of a sand
control screen assembly in its running configuration that embodies principles of the present
invention and is generally designated 40. Sand control screen assembly 40 includes base pipe
42 that defines an internal flow path 44. Base pipe 42 has a plurality of openings 46.
Positioned around base pipe 42 is a swellable material layer 48. Swellable material layer 48
is attached to base pipe 42 by bonding or other suitable technique. Preferably, the thickness
of swellable material layer 48 is optimized based upon the diameter of sand control screen
assembly 40 and the diameter of wellbore 50 such that upon expansion, as explained in
greater detail below, substantially uniform contact between both swellable material layer 48
and radially extendable filter members 52 with the surface of wellbore 50 is achieved.
Preferably, radially extendable filter members 52 are circumferentially and longitudinally
distributed about sand control screen assembly 40 and provide a plurality of substantially
direct pathways for production fluids from the formation to enter internal flow path 44 of
base pipe 42.
[0052] In the illustrated embodiment and as best seen in figures 4A-4C, radially extendable
filter members 52 each includes a cylinder 54 that is attached to base pipe 42 by threading,
welding, friction fit or other suitable technique. Slidably positioned within cylinder 54 is a
radially telescoping piston 56. Attached to the outer surface of piston 56 is a filter retainer
58. Filter retainer 58 supports a filter medium 60. Filter medium 60 may comprise a
mechanical screening element such as a fluid-porous, particulate restricting, metal screen
having one or more layers of woven wire or fiber mesh that may be diffusion bonded or
sintered together to form a screen designed to allow fluid flow therethrough but prevent the
flow of particulate materials of a predetermined size from passing therethrough. In the
illustrated embodiment, filter medium 60 includes outer and inner drainage layers that have a
relatively course wire mesh with a filtration layer disposed therebetween having a relatively
fine mesh. It should be noted that other types of filter media may be used with the sand
control screen assemblies of the present invention, such as a wire screen, a prepack screen, a
ceramic screen, metallic beads such as stainless steel beads or sintered stainless steel beads
and the like. Filter medium 60 is sized according to the particular requirements of the
production zone into which it will be installed. Some exemplary sizes of the gaps in filter
medium 60 may be in the 20-250 standard mesh range.
[0053] Referring additionally now to figures 2B and 3B, therein are depicted cross sectional
views of sand control screen assembly 40 in its operating configuration. In the illustrated
embodiment, swellable material layer 48 has come in contact with an activating fluid, such as
a hydrocarbon fluid, water or gas, which has caused swellable material layer 48 to radially
expand into contact with the surface of wellbore 50, which, in the illustrated embodiment, is
the formation face. In addition, the radial expansion of swellable material layer 48 has
caused radially extendable filter members 52 to come into contact with the surface of
wellbore 50.
[0054] One benefit provided by the sand control screen assemblies of the present invention is
that in addition to providing a plurality of paths for formation fluids to enter internal flow
path 44 and filtering particulate materials out of the formation fluids, the sand control screen
assemblies of the present invention also provide support to the formation to prevent
formation collapse. Compared with convention expandable metal sand control screens as
discussed above, the sand control screen assemblies of the present invention provide
improved contact with the formation as greater radial expansion is achievable and the
swellable material layer is more compliant such that it is better able to conform to a
nonuniform wellbore face. In a preferred implementation, the sand control screen assemblies
of the present invention provide between about 500 psi and 2000 psi of collapse support to
the wellbore. Those skilled in the art will recognize that the collapse support provided by the
present invention can be optimized for a particular implementation though specific design
features of the base pipe and the swellable material layer.
[0055] Various techniques may be used for contacting swellable material layer 48 with an
appropriate activating fluid for causing swelling of swellable material layer 48. For example,
the activating fluid may already be present in the well when sand control screen assembly 40
is installed in the well, in which case swellable material layer 48 preferably includes a
mechanism for delaying the swelling of swellable material layer 48 such as an absorption
delaying or preventing coating or membrane, swelling delayed material compositions or the
like.
[0056] Alternatively, the activating fluid may be circulated through the well to swellable
material layer 48 after sand control screen assembly 40 is installed in the well. As another
alternative, the activating fluid may be produced into the wellbore from the formation
surrounding the wellbore. Thus, it will be appreciated that any method may be used for
causing swelling of swellable material layer 48 of sand control screen assembly 40 in keeping
with the principles of the invention.
[0057] Swellable material layer 48 is formed from one or more materials that swell when
contacted by an activation fluid, such as an inorganic or organic fluid. For example, the
material may be a polymer that swells multiple times its initial size upon activation by an
activation fluid that stimulates the material to expand. In one embodiment, the swellable
material is a material that swells upon contact with and/or absorption of a hydrocarbon, such
as an oil or a gas. The hydrocarbon is absorbed into the swellable material such that the
volume of the swellable material increases creating a radial expansion of the swellable
material. Preferably, the swellable material will swell until its outer surface and radially
extendable filter members 52 contact the formation face in an open hole completion or the
casing wall in a cased wellbore. The swellable material accordingly provides the energy to
radially extend radially extendable filter members 52 in contact with the formation.
[0058] Some exemplary swellable materials include elastic polymers, such as EPDM rubber,
styrene butadiene, natural rubber, ethylene propylene monomer rubber, ethylene propylene
diene monomer rubber, ethylene vinyl acetate rubber, hydrogenized acrylonitrile butadiene
rubber, acrylonitrile butadiene rubber, isoprene rubber, chloroprene rubber and
polynorbornene. These and other swellable materials swell in contact with and by absorption
of hydrocarbons so that the swellable materials expand. In one embodiment, the rubber of
the swellable materials may also have other materials dissolved in or in mechanical mixture
therewith, such as fibers of cellulose. Additional options may be rubber in mechanical
mixture with polyvinyl chloride, methyl methacrylate, acrylonitrile, ethylacetate or other
polymers that expand in contact with oil.
[0059] In another embodiment, the swellable material is a material that swells upon contact
with water. In this case, 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 and preferably a water-swellable hydrophobic porous copolymer. Other polymers
useful in accordance with the present invention can be prepared from a variety of hydrophilic
monomers and hydrophobically modified hydrophilic monomers. Examples of particularly
suitable hydrophilic monomers which can be utilized include, but are not limited to,
acrylamide, 2-acrylamido-2-methyl propane sulfonic acid, N,N-dimethylacrylamide, vinyl
pyrrolidone, dimethylaminoethyl methacrylate, acrylic acid, trimethylarnmoniumethyl
methacrylate chloride, dimethylaminopropylmethacrylamide, methacrylamide and
hydroxyethyl acrylate.
[0060] A variety of hydrophobically modified hydrophilic monomers can also be utilized to
form the polymers useful in accordance with this invention. Particularly suitable
hydrophobically modified hydrophilic monomers include, but are not limited to, alkyl
acrylates, alkyl methacrylates, alkyl acrylamides and alkyl methacrylamides wherein the
alkyl radicals have from about 4 to about 22 carbon atoms, alkyl dimethylammoniumethyl
methacrylate bromide, alkyl dimethylammoniumethyl methacrylate chloride and alkyl
dimethylammoniumethyl methacrylate iodide wherein the alkyl radicals have from about 4 to
about 22 carbon atoms and alkyl dimethylammonium-propylmethacrylamide bromide, alkyl
dimethylammonium propylmethacrylamide chloride and alkyl dimethylammonium-
propylmethacrylamide iodide wherein the alkyl groups have from about 4 to about 22 carbon
atoms.
[0061] Polymers which are useful in accordance with the present invention can be prepared
by polymerizing any one or more of the described hydrophilic monomers with any one or
more of the described hydrophobically modified hydrophilic monomers. The polymerization
reaction can be performed in various ways that are known to those skilled in the art, such as
those described in United States Patent Number 6,476,169 which is hereby incorporated by
reference for all purposes.
[0062] Suitable polymers may have estimated molecular weights in the range of from about
100,000 to about 10,000,000 and preferably in the range of from about 250,000 to about
3,000,000 and may 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.
[0063] Other polymers useful in accordance with the present invention include
hydrophobically modified polymers, hydrophobically modified water-soluble polymers and
hydrophobically modified copolymers thereof. Particularly suitable hydrophobically
modified polymers include, but are not limited to, hydrophobically modified
polydimethylaminoethyl methacrylate, hydrophobically modified polyacrylamide and
hydrophobically modified copolymers of dimethylaminoethyl methacrylate and vinyl
pyrollidone.
[0064] As another example, the swellable material may be a salt polymer such as
polyacrylamide or modified crosslinked poly(meth)acryIate that has the tendency to attract
water from salt water through osmosis wherein water flows from an area of low salt
concentration, the formation water, to an area of high salt concentration, the salt polymer,
across a semi permeable membrane, the interface between the polymer and the production
fluids, that allows water molecules to pass therethrough but prevents the passage of dissolved
salts therethrough.
[0065] In the illustrated embodiment, radially extendable filter members 52 have been
designed to be compliant with the surface of the wellbore. Specifically, radially extendable
filter members 52 have a relatively narrow circumferential dimension and a relatively
extended longitudinal dimension, as best seen in the comparison of figures 2A-2B to figures
3A-3B. In certain embodiments, the ratio between the circumferential dimension and the
longitudinal dimension of radially extendable filter members 52 is between about 1 to 2 and
about 1 to 10. In other embodiments, the ratio between the circumferential dimension and the
longitudinal dimension of radially extendable filter members 52 is between about 1 to 10 and
about 1 to 30.
[0066] In addition, extendable filter members 52 provide a relatively large interface contact
area with the formation. Having this large interface contact area reduces the localized draw
down associated with production into the wellbore as compared to fluid inlets having
relatively small points of entry, thereby reducing the risk of coning of an unwanted fluid such
as water or gas in an oil production operation. Having a relatively large interface contact area
compared to the fluid discharge area of individual radially extendable filter members 52 or
collections of radially extendable filter members 52 further reduces localized drawdown, as
explained in greater detail below.
[0067] Even though radially extendable filter members 52 have been depicted as having a
particular cross sectional shape, it should be understood by those skilled in the art that the
radially extendable filter members of the present invention could alternatively have cross
sections of different shapes including circles, such as radially extendable filter member 70 of
figure 5A, rectangles, such as radially extendable filter member 72 of figure 5B, and other
shapes such as ovals, squares, diamonds and the like as well as other non symmetric cross
sections, all such shapes being considered within the scope of the present invention. Also,
even though radially extendable filter members 52 have been depicted as having a contoured
outer surface, it should be understood by those skilled in the art that the radially extendable
filter members of the present invention could alternatively have an outer surface having a
different configuration including a relatively flat outer surface, such as radially extendable
filter members 74, 76 of figures 6A-6B, a non uniform outer surface, such as radially
extendable filter member 78, 80 of figures 6C-6D, or the like.
[0068] Even though radially extendable filter members 52 have been described as having a
filter medium attached to a filter retainer, those skilled in the art will recognize that other
types of radially extendable filter members could alternatively be used. For example, as best
seen in figure 7A, radially extendable filter member 90 includes a cylinder 92 that is attached
to a base pipe by threading, welding, friction fit or other suitable technique. Slidably
positioned within cylinder 92 is a radially telescoping piston 94. Extending longitudinally
from piston 94 is a tubular member 96 having a plurality of perforations 98. Disposed within
tubular member 96 is a filter medium 100 that is depicted as steel or ceramic balls or beads
that may be sintered within tubular member 96. Alternatively, the filter medium could be a
single or multiple layer sintered or unsintered mesh, prepacked or resin coated sand,
combinations of the above and the like.
[0069] Additionally, even though radially extendable filter member 90 has been described as
having tubular members in the shape of a "T", those skilled in the art will recognize that other
tubular configurations could alternatively be used and would be considered within the scope
of the present invention. For example, as best seen in figure 7B, radially extendable filter
member 110 is formed in the shape of an "L". Specifically, radially extendable filter member
110 includes a cylinder 112 that is attached to a base pipe by threading, welding, friction fit
or other suitable technique. Slidably positioned within cylinder 112 is a radially telescoping
piston 114. Extending longitudinally from piston 114 is a tubular member 116 having a
plurality of perforations that are covered by a suitable filter medium 118. Likewise, as best
seen in figure 7C, radially extendable filter member 120 is formed in the shape of a "U".
Specifically, radially extendable filter member 120 includes a pair of cylinders 122 that are
attached to a base pipe by threading, welding, friction fit or other suitable technique. Slidably
positioned within cylinders 122 are a pair of radially telescoping pistons 124. Extending
longitudinally between pistons 124 is a tubular member 126 having a plurality of perforations
that are covered by a suitable filter medium 128. Further, as best seen in figure 7D, radially
extendable filter member 130 is formed in the shape of an "M". Specifically, radially
extendable filter member 130 includes three cylinders 132 that are attached to a base pipe by
threading, welding, friction fit or other suitable technique. Slidably positioned within
cylinders 132 are three radially telescoping pistons 134. Extending longitudinally between
pistons 134 is a tubular member 136 having a plurality of perforations that are covered by a
pair of suitable filter media 138. Accordingly, it can be seen that radially extendable filter
members that provide one or more direct paths for formation fluids to enter an internal flow
path of a base pipe can take many shapes or configurations, each of which are considered to
be within the scope of the present invention.
[0070] Referring again to figures 2A-4B, in certain embodiments, the outer layer of filter
medium 60 may primarily serve as a drainage layer to allow formations fluids to travel
annularly or longitudinally within filter medium 60. Likewise, the outer layer of filter
medium 60 may also serve as a carrier for a chemical treatment or other agent. The use of
this configuration is beneficial, for example, if a filter cake has previously formed on the
surface of the formation, then the stand off provided by the outer drainage layer will prevent
damage to filtration layers within filter medium 60 and allow removal of the filter cake using
acid or other reactive substance.
[0071] In one embodiment, the outer layer of filter medium 60 may have the reactive
substance impregnated therein. For example, the reactive substance may fill the voids in the
outer layer of filter medium 60 during installation. Preferably, the reactive substance is
degradable when exposed to a subterranean well environment. More preferably, the reactive
substance degrades when exposed to water at an elevated temperature in a well. Most
preferably, the reactive substance is provided as described in United States Patent No.
7,036,587 which is hereby incorporated by reference for all purposes.
[0072] In certain embodiments, the reactive substance includes a degradable polymer.
Suitable examples of degradable polymers that may be used in accordance with the present
invention include polysaccharides such as dextran or cellulose, chitins, chitosans, proteins,
aliphatic polyesters, poly(lactides), poly(glycolides), poly(e-caprolactones), poly(anhydrides),
poly(hydroxybutyrates), aliphatic polycarbonates, poly(orthoesters), poly(amino acids),
poly(ethylene oxides), and polyphosphazenes. Of these suitable polymers, aliphatic
polyesters such as poly(lactide) or poly(lactic acid) and polyanhydrides are preferred.
[0073] The reactive substance may degrade in the presence of a hydrated organic or
inorganic compound solid, which may be included in sand control screen assembly 40, so that
a source of water is available in the well when the screens are installed. Alternatively,
another water source may be delivered to the reactive substance after sand control screen
assembly 40 is conveyed into the well, such as by circulating the water source down to the
well or formation water may be used as the water source.
[0074] Referring next to figures 8A-8B, therein are depicted side and front views, partially in
cross section, of a radially extendable filter member for use in a sand control screen assembly
that embodies principles of the present invention and is generally designated 140. Radially
extendable filter member 140 includes a cylinder 142 that is attached to a base pipe by a
suitable technique such as those discussed herein. Slidably positioned within cylinder 142 is
a radially telescoping piston 144. Attached to the outer surface of piston 144 is a filter
retainer 146. Filter retainer 146 supports a filter medium 148. Filter medium 148 may
comprise a mechanical screening element such as those discussed herein. As discussed
above, the large interface contact area provided by filter medium 148 reduces the localized
draw down associated with production into the wellbore as compared to production into a
relatively small point of entry. This benefit is enhanced by a relatively large ratio between
the interface contact area of filter medium 148 and the formation and the fluid discharge area
of radially extendable filter member 148. A large ratio can be achieved by providing a
relatively narrow or restrictive exit path for fluids traveling through radially extendable filter
member 148. The ratio may be optimized by positioning a fluid flow control device 150
within the exit path of filter medium 148 such as cylinder 142 or piston 144, as illustrated. In
this embodiment, fluid flow control device 150 is used to control the rate of production
through radially extendable filter member 148. For example, fluid flow control device 150
may take the form of an inflow control device such as a nozzle, a flow tube, an orifice or
other flow restrictor.
[0075] Alternatively, depending upon the desired operation, fluid flow control device 150
may take a variety of other forms. For example, it may be desirable to temporarily prevent
fluid flow through radially extendable filter member 148. In this case, fluid flow control
device 150 may be a dissolvable, removable or shearable plug formed from sand, salt, wax,
aluminum, zinc or the like or may be a pressure activated device such as burst disk. As
another example, it may be desirable to prevent fluid loss into the formation during high
pressure operations internal to the sand control screen assembly including radially extendable
filter member 148, in which case, fluid flow control device 150 may be a one-way valve or a
check valve. As yet another example, it may be desirable to control the type of fluid entering
the sand control screen assembly including radially extendable filter member 148, in which
case, fluid flow control device 150 may be a production control device such as a valve that
closes responsive to contact with an undesired fluid, such as water. Such valves may be
actuated by a swellable material including those discussed above, organic fibers, an osmotic
cell or the like.
[0076] Referring next to figure 9A, therein is depicted a sand control screen assembly in its
running configuration that embodies principles of the present invention and is generally
designated 160. Sand control screen assembly 160 includes base pipe 162 and an inner
sleeve 164 that includes a plurality of openings 166 and defines an internal flow path 168.
Base pipe 162 has a plurality of openings 170. Positioned around base pipe 162 is a
swellable material layer 172. Swellable material layer 172 is attached to base pipe 162 by
bonding or other suitable technique. Sand control screen assembly 160 includes a plurality of
radially extendable filter members 174 that are constructed and operate in the manner
described herein and are circumferentially distributed around swellable material layer 172 at
a plurality of longitudinal locations. As described above, upon activation of swellable
material layer 172, extendable filter members 174 are placed in contact with wellbore 176, as
best seen in figure 9B.
[0077] Disposed between base pipe 162 and sleeve 164 is a pair of fluid flow control devices
178, 180. As described above, depending upon the desired operation, fluid flow control
devices 178, 180 may take a variety of forms including in any combination of dissolvable,
removable or shearable plugs, a burst disk, a one-way valve, a check valve, a nozzle, a flow
tube, an orifice or other flow restrictor, a valve that closes responsive to contact with an
undesired fluid and the like. In this embodiment, production through multiple radially
extendable filter members 174 is combined in the common annular chamber or manifold 182
defined between base pipe 162 and sleeve 164. This provides the benefit of a uniform draw
down being applied across the entire length and circumference of sand control screen
assembly 160. If it is desired to have unrestricted flow, in certain embodiments, sleeve 164 is
removable by mechanical or chemical means.
[0078] Additionally or alternatively, a sliding sleeve (not pictured) may be operably
associated with sleeve 164 and openings 166. The sliding sleeve may be disposed internally
of sleeve 164 within internal flow path 168 or may preferably be disposed externally of
sleeve 164 within annular chamber 182. The sliding sleeve may have an open position
wherein fluid flow through openings 166 is allowed and a closed position wherein fluid flow
though openings 166 is prevented. In addition, the position of the sliding sleeve may be
infinitely variable such that the sliding sleeve may provide a choking function. The sliding
sleeve may be operated mechanically, electrically, hydraulically or by other suitable means.
[0079] Referring to figure 10A, therein is depicted a cross sectional view of a sand control
screen assembly in its running configuration that embodies principles of the present invention
and is generally designated 190. Sand control screen assembly 190 includes a base pipe 192
that defines an internal flow path 194. Base pipe 192 has a plurality of openings 196 each of
which has a radially extendable filter member 198 associated therewith. Preferably, radially
extendable filter members 198 are circumferentially and longitudinally distributed about sand
control screen assembly 190 to provide a plurality of substantially direct pathways for
production fluids from the formation to internal flow path 194 of base pipe 192.
[0080] Radially extendable filter members 198 each includes a cylinder 200 that is attached
to base pipe 192 by threading, welding, friction fit or other suitable technique. Slidably
positioned within cylinder 200 is a radially telescoping piston 202. Attached to the outer
surface of piston 202 is a filter retainer 204. Filter retainer 204 supports an outer filter
member 206. As illustrated, outer filter member 206 is a mechanical screening element such
as a woven wire or fiber mesh. In addition, disposed within piston 202 is a second screening
element 208 such as prepacked or resin coated sand, metallic or ceramic balls or beads that
may be sintered or unsintered or the like. Radially extendable filter members 198 also
include a fluid flow control device 210. In this embodiment that does not include a swellable
material layer, pressure within internal flow path 194 of sand control screen assembly 190 is
preferably used to shift radially extendable filter members 198 from their running position to
their operating position, as best seen in figure 10B. Accordingly, fluid flow control devices
210 are preferably one of dissolvable, removable or shearable plugs, a burst disk, a one-way
valve, a check valve, or other device that will allow internal flow path 194 to be pressurize
and will also allow production of fluids from the formation, through fluid flow control
devices 210 into internal flow path 194.
[0081] Referring to figure 11 A, therein is depicted a cross sectional view of a sand control
screen assembly in its running configuration that embodies principles of the present invention
and is generally designated 220. Sand control screen assembly 220 includes a base pipe 222
that defines an internal flow path 224. Base pipe 222 has a plurality of openings 226 each of
which has a radially extendable filter member 228 associated therewith. Preferably, radially
extendable filter members 228 are circumferentially and longitudinally distributed about sand
control screen assembly 220 to provide a plurality of substantially direct pathways for
production fluids from the formation to internal flow path 224 of base pipe 222.
[0082] Radially extendable filter members 228 each includes a cylinder 230 that is attached
to base pipe 222 by threading, welding, friction fit or other suitable technique. Slidably
positioned within cylinder 230 is a radially telescoping piston 232. Attached to the outer
surface of each piston 232 is a longitudinally extending perforated tubular member 234.
Disposed within tubular member 234 is a screening element 236 such as prepacked or resin
coated sand, metallic or ceramic balls or beads that may be sintered or unsintered or the like.
Radially extendable filter members 228 include a pair of fluid flow control devices 238. As
this embodiment does not include a swellable material layer, pressure within internal flow
path 224 of sand control screen assembly 220 is preferably used to shift radially extendable
filter members 228 from their running position to their operating position, as best seen in
figure 11B. Accordingly, fluid flow control devices 238 are preferably one of dissolvable,
removable or shearable plugs, a burst disk, a one-way valve, a check valve, or other devices
that will allow internal flow path 224 to be pressurize and will also allow production of fluids
from the formation, through fluid flow control devices 238 into internal flow path 224.
[0083] While this invention has been described with reference to illustrative embodiments,
this description is not intended to be construed in a limiting sense. Various modifications and
combinations of the illustrative embodiments as well as other embodiments of the invention,
will be apparent to persons skilled in the art upon reference to the description. It is, therefore,
intended that the appended claims encompass any such modifications or embodiments.
What is claimed is:
1. A sand control screen assembly operably positionable within a wellbore, the
sand control screen assembly comprising:
a base pipe having a plurality of circumferentially and longitudinally distributed
openings in a sidewall portion thereof and an internal flow path; and
a plurality of circumferentially and longitudinally distributed, radially extendable
filter members, each radially extendable filter member operably associated with at least one
of the openings of the base pipe, the radially extendable filter members having a
circumferential dimension that is less than a longitudinal dimension thereof;
wherein the radially extendable filter members have a radially retracted running
configuration and a radially extended operating configuration.
2. The sand control screen assembly as recited in claim 1 further comprising a
swellable material layer disposed between the base pipe and at least a portion of the radially
extendable filter members such that, in response to contact with an activating fluid, radial
expansion of the swellable material layer causes the radially extendable filter members to
operate from their running configuration to their operating configuration.
3. The sand control screen assembly as recited in claim 2 wherein the activating fluid
is at least one of a hydrocarbon fluid, water and gas.
4. The sand control screen assembly as recited in claim 1 wherein the radially
extendable filter members further comprise a cylinder that is coupled to the base pipe and a
radially telescoping piston slidably received within the cylinder.
5. The sand control screen assembly as recited in claim 4 wherein the radially
extendable filter members further comprise a filter retainer and filter medium.
6. The sand control screen assembly as recited in claim 4 wherein the radially
extendable filter members further comprise a perforated tubular.
7. The sand control screen assembly as recited in claim 1 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is at least 1 to 2.
8. The sand control screen assembly as recited in claim 1 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is between about 1 to 2 and about 1 to 10.
9. The sand control screen assembly as recited in claim 1 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is between about 1 to 10 and about 1 to 30.
10. The sand control screen assembly as recited in claim 1 further comprising a fluid
flow control device operably associated with each of the radially extendable filter members.
11. The sand control screen assembly as recited in claim 1 further comprising a fluid
flow control device operably associated with a plurality of the radially extendable filter
members.
12. The sand control screen assembly as recited in claim 1 wherein a filter medium
associated with the radially extendable filter members comprises at least one of a single layer
mesh screen, a multiple layer mesh screen, a wire wrapped screen, a prepack screen, a
ceramic screen, a fluid porous, particulate resistant sintered wire mesh screen and a fluid
porous, particulate resistant diffusion bonded wire mesh screen.
13. The sand control screen assembly as recited in claim 1 wherein, in the radially
extended operating configuration, the radially extendable filter members contact the wellbore.
14. A sand control screen assembly operably positionable within a wellbore, the
sand control screen assembly comprising:
a base pipe having a plurality of circumferentially and longitudinally distributed
openings in a sidewall portion thereof and an internal flow path;
a plurality of circumferentially and longitudinally distributed, radially extendable
filter members, each radially extendable filter member operably associated with at least one
of the openings of the base pipe, the radially extendable filter members having a
circumferential dimension that is less than a longitudinal dimension thereof; and
a swellable material layer disposed exteriorly of the base pipe;
wherein, in response to contact with an activating fluid, radial expansion of the
swellable material layer causes at least a portion of the radially extendable filter members to
be displaced toward a surface of the wellbore.
15. The sand control screen assembly as recited in claim 14 wherein the activating
fluid is at least one of a hydrocarbon fluid, water and gas.
16. The sand control screen assembly as recited in claim 14 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is at least 1 to 2.
17. The sand control screen assembly as recited in claim 14 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is between about 1 to 2 and about 1 to 10.
18. The sand control screen assembly as recited in claim 14 wherein the ratio between
the circumferential dimension and the longitudinal dimension of the radially extendable filter
members is between about 1 to 10 and about 1 to 30.
19. The sand control screen assembly as recited in claim 14 further comprising a fluid
flow control device operably associated with each of the radially extendable filter members.
20. The sand control screen assembly as recited in claim 14 further comprising a fluid
flow control device operably associated with a plurality of the radially extendable filter
members.
21. The sand control screen assembly as recited in claim 14 wherein a filter medium
associated with the radially extendable filter members comprises at least one of a single layer
mesh screen, a multiple layer mesh screen, a wire wrapped screen, a prepack screen, a
ceramic screen, a fluid porous, particulate resistant sintered wire mesh screen and a fluid
porous, particulate resistant diffusion bonded wire mesh screen.
22. The sand control screen assembly as recited in claim 14 wherein, in response to
contact with an activating fluid, radial expansion of the swellable material layer causes at
least a portion of the radially extendable filter members to contact the wellbore.
23. A method of installing a sand control screen assembly in a wellbore, the
method comprising:
running the sand control screen assembly to a target location within the wellbore, the
sand control screen assembly including a plurality of circumferentially and longitudinally
distributed, radially extendable filter members each of which is operably associated with at
least one opening of a base pipe, the radially extendable filter members having a
circumferential dimension that is less than a longitudinal dimension thereof; and
operating the radially extendable filter members from a radially retracted running
configuration to a radially extended operating configuration.
24. The method as recited in claim 23 wherein the step of operating the radially
extendable filter members from a radially retracted running configuration to a radially
extended operating configuration further comprises radially expanding a swellable material
layer disposed around the base pipe in response to contact with the activating fluid.
25. The method as recited in claim 23 wherein the step of operating the radially
extendable filter members from a radially retracted running configuration to a radially
extended operating configuration further comprises placing at least a portion of the radially
extendable filter members in contact with the wellbore.
26. A sand control screen assembly operably positionable within a wellbore, the
sand control screen assembly comprising:
a first tubular having a plurality of openings in a sidewall portion thereof;
a second tubular disposed within the first tubular forming an chamber therebetween,
the second tubular having at least one opening in a sidewall portion thereof and an internal
flow path;
a plurality of radially extendable filter members, each radially extendable filter
member operably associated with at least one of the openings of the first tubular; and
a swellable material layer disposed exteriorly of the first tubular,
wherein, in response to contact with an activating fluid, radial expansion of the
swellable material layer causes at least a portion of the radially extendable filter members to
be displaced toward a surface of the wellbore.
27. The sand control screen assembly as recited in claim 26 wherein the activating
fluid is at least one of a hydrocarbon fluid, water and gas.
28. The sand control screen assembly as recited in claim 26 wherein the chamber
formed between the first and second tubulars is an annular chamber.
29. The sand control screen assembly as recited in claim 26 further comprising a
fluid flow control device disposed in the chamber formed between the first and second
tubulars.
30. The sand control screen assembly as recited in claim 29 wherein the fluid flow
control device is selected from dissolvable plugs, removable plugs, shearable plugs, burst
disks, one-way valves, check valves, nozzles, flow tubes, orifices, flow restrictors and valves
that closes responsive to contact with an undesired fluid.
31. The sand control screen assembly as recited in claim 26 further comprising a
pair of fluid flow control devices disposed in series within the chamber formed between the
first and second tubulars.
32. The sand control screen assembly as recited in claim 31 wherein each of the
fluid flow control devices is selected from dissolvable plugs, removable plugs, shearable
plugs, burst disks, one-way valves, check valves, nozzles, flow tubes, orifices, flow
restrictors and valves that closes responsive to contact with an undesired fluid.
33. The sand control screen assembly as recited in claim 26 wherein a filter
medium associated with the radially extendable filter members comprises at least one of a
single layer mesh screen, a multiple layer mesh screen, a wire wrapped screen, a prepack
screen, a ceramic screen, a fluid porous, particulate resistant sintered wire mesh screen and a
fluid porous, particulate resistant diffusion bonded wire mesh screen.
34. The sand control screen assembly as recited in claim 26 wherein, in response
to contact with an activating fluid, radial expansion of the swellable material layer causes at
least a portion of the radially extendable filter members to contact the wellbore.
35. The sand control screen assembly as recited in claim 26 wherein the second
tubular is removable.
36. The sand control screen assembly as recited in claim 26 wherein the radially
extendable filter members are circumferentially and longitudinally distributed about the first
tubular.
37. The sand control screen assembly as recited in claim 26 wherein the radially
extendable filter members have a circumferential dimension that is less than a longitudinal
dimension thereof.

A sand control screen assembly (40) is operably positionable within a wellbore (50). The sand control screen assembly
(40) includes a base pipe (42) having a plurality of openings (46) in a sidewall portion thereof and an internal flow path
(44). A plurality of radially extendable filter members (52) are each operably associated with at least one of the openings (46) of
the base pipe (42). The radially extendable filter members (52) have a circumferential dimension mat is less than a longitudinal dimension
thereof. The radially extendable filter members (52) have a radially retracted running configuration and a radially extended
operating configuration, in which, the radially extendable filter members (52) preferably contact the wellbore (50). The filter
members (52) can also be extended by a swellable material (48) in response to contact with an activating fluid.