U.S. patent application number 12/835023 was filed with the patent office on 2011-01-13 for water sensitive porous medium to control downhole water production and method therefor.
This patent application is currently assigned to Baker Hughes Incorporated. Invention is credited to Tianping Huang, Richard A. Mitchell.
Application Number | 20110005752 12/835023 |
Document ID | / |
Family ID | 45470005 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110005752 |
Kind Code |
A1 |
Huang; Tianping ; et
al. |
January 13, 2011 |
Water Sensitive Porous Medium to Control Downhole Water Production
and Method Therefor
Abstract
Water production produced from a subterranean formation is
inhibited or controlled by consolidated water sensitive porous
medium (WSPM) packed within the flow path of the wellbore device
container. The WSPM includes solid particles having a water
hydrolyzable polymer at least partially coating the particles. The
WSPM is packed under pressure within the flow path of the wellbore
device container to consolidate it. The WSPM increases resistance
to flow as water content increases in the fluid flowing through the
flow path and decreases resistance to flow as water content
decreases in the fluid flowing through the flow path.
Inventors: |
Huang; Tianping; (Spring,
TX) ; Mitchell; Richard A.; (Houston, TX) |
Correspondence
Address: |
Mossman, Kumar and Tyler, PC
P.O. Box 421239
Houston
TX
77242
US
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
45470005 |
Appl. No.: |
12/835023 |
Filed: |
July 13, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12191921 |
Aug 14, 2008 |
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12835023 |
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12606464 |
Oct 27, 2009 |
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12191921 |
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Current U.S.
Class: |
166/276 ;
166/279; 166/319 |
Current CPC
Class: |
E21B 43/32 20130101;
E21B 34/08 20130101 |
Class at
Publication: |
166/276 ;
166/319; 166/279 |
International
Class: |
E21B 43/34 20060101
E21B043/34; E21B 43/02 20060101 E21B043/02 |
Claims
1. A wellbore device for controlling a flow of a fluid through a
flow path therein, the wellbore device comprising: a container
comprising the flow path; and a consolidated water sensitive porous
medium (WSPM) packed within the flow path of the container, the
WSPM comprising: solid particles; and at least one water
hydrolyzable polymer at least partially coated on the solid
particles.
2. The wellbore device of claim 1 where the average particle size
of the solid particles ranges from about 10 to about 100 mesh
(about 2000 to about 150 microns).
3. The wellbore device of claim 1 where the WSPM is packed within
the container at a pressure ranging from about 50 to about 2000 psi
(about 0.3 to about 13.8 MPa).
4. The wellbore device of claim 1 where the ratio of weight of
solid particles to weight of dry water hydrolyzable polymer ranges
from about 10,000:1 to about 10:1.
5. The wellbore device of claim 1 where the water hydrolyzable
polymer is crosslinked.
6. The wellbore device of claim 1 where the water hydrolyzable
polymer has a weight average molecular weight greater than 100,000
and is selected from the group consisting of: homopolymers and
copolymers of acrylamide, sulfonated or quaternized homopolymers
and copolymers of acrylamide, polyvinylalcohols, polysiloxanes,
hydrophilic natural gum polymers and chemically modified
derivatives thereof; crosslinked homopolymers and copolymers of
acrylamide, crosslinked sulfonated or quaternized homopolymers and
copolymers of acrylamide, crosslinked polyvinylalcohols,
crosslinked polysiloxanes, crosslinked hydrophilic natural gum
polymers and chemically modified derivatives thereof; copolymers
having a hydrophilic monomeric unit, where the hydrophilic
monomeric unit is selected from the group consisting of ammonium
and alkali metal salt of acrylamidomethylpropanesulfonic acid, a
first anchoring monomeric unit based on N-vinylformamide and a
filler monomeric unit, where the filler monomeric unit is selected
from the group consisting of acrylamide and methylacrylamide; and
copolymers of vinylamide monomers and monomers containing ammonium
or quaternary ammonium moieties, copolymers of vinylamide monomers
and monomers comprising vinylcarboxylic acid monomers and/or
vinylsulfonic acid monomers, and salts thereof, and these
copolymers comprising a crosslinking monomer selected from the
group consisting of bis-acrylamide, dialylamine,
N,N-diallylacrylamide, divinyloxyethane, divinyldimethylsilane.
7. The wellbore device of claim 1 where the WSPM increases a
resistance to flow as water content increases in the fluid flowing
through the flow path and decreases a resistance to flow as water
content decreases in the fluid flowing through the flow path.
8. The wellbore device of claim 1 where the solid particles
comprise sand, glass beads, ceramic beads, metal beads, bauxite
grains, walnut shell fragments, aluminum pellets, nylon pellets and
combinations thereof.
9. A method of constructing a wellbore device for controlling a
flow of a fluid through a flow path in the wellbore device, the
method comprising: mixing solid particles with at least one water
hydrolyzable polymer in the presence of a fluid selected from the
group consisting of water and brine to give a mixture; at least
partially drying the mixture; packing the at least partially dried
mixture into the flow path of a container of the wellbore device to
form a consolidated water sensitive porous medium (WSPM).
10. The method of claim 9 further comprising: where in mixing the
solid particles with the water hydrolyzable polymer, the mixing is
in the presence of an amount of water effective to fully hydrolyze
the water hydrolyzable polymer; and crosslinking the water
hydrolyzable polymer with at least one crosslinking agent.
11. The method of claim 9 where the average particle size of the
solid particles ranges from about 10 to about 100 mesh (about 2000
to about 150 microns).
12. The method of claim 9 where the WSPM is packed within the
wellbore device container at a pressure ranging from about 50 to
about 2000 psi (about 0.3 to about 13.8 MPa).
13. The method of claim 9 where the ratio of weight of solid
particles to weight of dry water hydrolyzable polymer ranges from
about 10,000:1 to about 10:1.
14. The method of claim 9 where the water hydrolyzable polymer has
a weight average molecular weight greater than 100,000 and is
selected from the group consisting of: homopolymers and copolymers
of acrylamide, sulfonated or quaternized homopolymers and
copolymers of acrylamide, polyvinylalcohols, polysiloxanes,
hydrophilic natural gum polymers and chemically modified
derivatives thereof; crosslinked homopolymers and copolymers of
acrylamide, crosslinked sulfonated or quaternized homopolymers and
copolymers of acrylamide, crosslinked polyvinylalcohols,
crosslinked polysiloxanes, crosslinked hydrophilic natural gum
polymers and chemically modified derivatives thereof; copolymers
having a hydrophilic monomeric unit, where the hydrophilic
monomeric unit is selected from the group consisting of ammonium
and alkali metal salt of acrylamidomethylpropanesulfonic acid, a
first anchoring monomeric unit based on N-vinylformamide and a
filler monomeric unit, where the filler monomeric unit is selected
from the group consisting of acrylamide and methylacrylamide; and
copolymers of vinylamide monomers and monomers containing ammonium
or quaternary ammonium moieties, copolymers of vinylamide monomers
and monomers comprising vinylcarboxylic acid monomers and/or
vinylsulfonic acid monomers, and salts thereof, and these
copolymers comprising a crosslinking monomer selected from the
group consisting of bis-acrylamide, diallylamine,
N,N-diallylacrylamide, divinyloxyethane, divinyldimethylsilane.
15. The method of claim 9 where the WSPM increases a resistance to
flow as water content increases in the fluid flowing through the
flow path and decreases a resistance to flow as water content
decreases in the fluid flowing through the flow path.
16. The method of claim 9 where the solid particles comprise sand,
glass beads, ceramic beads, metal beads, bauxite grains, walnut
shell fragments, aluminum pellets, nylon pellets and combinations
thereof.
17. A method for controlling a flow of a fluid through a flow path
in a wellbore device within a wellbore, the method comprising:
flowing the fluid through the flowpath in the wellbore device; and
controlling a resistance to flow of the fluid through the flow path
whereby: resistance to flow increases as water content of the fluid
increases, and resistance to flow decreases as water content of the
fluid decreases; the wellbore device comprising: a container
comprising the flow path; and a consolidated water sensitive porous
medium (WSPM) packed within the flow path of the container, the
WSPM comprising: solid particles; and at least one water
hydrolyzable polymer at least partially coated on the solid
particles.
18. The method of claim 17 where the average particle size of the
solid particles ranges from about 10 to about 100 mesh (about 2000
to about 150 microns).
19. The method of claim 17 where the WSPM is packed within the
wellbore device container at a pressure ranging from about 50 to
about 2000 psi (about 0.3 to about 13.8 MPa).
20. The method of claim 17 where the ratio of weight of solid
particles to weight of dry water hydrolyzable polymer ranges from
about 10,000:1 to about 10:1.
21. The method of claim 17 where the water hydrolyzable polymer is
crosslinked.
22. The method of claim 17 where the water hydrolyzable polymer has
a weight average molecular weight greater than 100,000 and is
selected from the group consisting of: homopolymers and copolymers
of acrylamide, sulfonated or quaternized homopolymers and
copolymers of acrylamide, polyvinylalcohols, polysiloxanes,
hydrophilic natural gum polymers and chemically modified
derivatives thereof; crosslinked homopolymers and copolymers of
acrylamide, crosslinked sulfonated or quaternized homopolymers and
copolymers of acrylamide, crosslinked polyvinylalcohols,
crosslinked polysiloxanes, crosslinked hydrophilic natural gum
polymers and chemically modified derivatives thereof; copolymers
having a hydrophilic monomeric unit, where the hydrophilic
monomeric unit is selected from the group consisting of ammonium
and alkali metal salt of acrylamidomethylpropanesulfonic acid, a
first anchoring monomeric unit based on N-vinylformamide and a
filler monomeric unit, where the filler monomeric unit is selected
from the group consisting of acrylamide and methylacrylamide; and
copolymers of vinylamide monomers and monomers containing ammonium
or quaternary ammonium moieties, copolymers of vinylamide monomers
and monomers comprising vinylcarboxylic acid monomers and/or
vinylsulfonic acid monomers, and salts thereof, and these
copolymers comprising a crosslinking monomer selected from the
group consisting of bis-acrylamide, diallylamine,
N,N-diallylacrylamide, divinyloxyethane, divinyldimethylsilane.
23. The method of claim 17 where the solid particles comprise sand,
glass beads, ceramic beads, metal beads, bauxite grains, walnut
shell fragments, aluminum pellets, nylon pellets and combinations
thereof.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 12/191,921 filed Aug. 14, 2008 and
is also a continuation-in-part application of U.S. patent
application Ser. No. 12/606,464 filed Oct. 27, 2009.
TECHNICAL FIELD
[0002] The present invention relates to apparatus and methods for
controlling the production of fluid through a device in a wellbore
and methods for constructing said apparatus, and more particularly
relates, in one non-limiting embodiment, to apparatus for and
methods of inhibiting and controlling the flow of water through a
wellbore from subterranean formations during hydrocarbon recovery
operations and methods for constructing said apparatus.
TECHNICAL BACKGROUND
[0003] Hydrocarbons such as oil and gas are recovered from a
subterranean formation using a wellbore drilled into the formation.
Unwanted water production is a major problem in maximizing the
hydrocarbon production potential of a subterranean well. Tremendous
costs may be incurred from separating and disposing of large
amounts of produced water, inhibiting the corrosion of tubulars
contacted by the water, replacing corroded tubular equipment
downhole, and surface equipment maintenance. Shutting off,
preventing and controlling unwanted water production is a necessary
condition to maintaining a productive field.
[0004] Oil and gas wells are typically completed by placing a
casing along the wellbore length and perforating the casing
adjacent each such production zone to extract the formation fluids
(such as hydrocarbons) into the wellbore. These production zones
are sometimes separated or isolated from each other by installing a
packer between the production zones. Fluid from each production
zone entering the wellbore is drawn into a tubing that runs to the
surface. It is desirable to have substantially even drainage along
the production zone. Uneven drainage may result in undesirable
conditions such as an invasive gas cone or water cone. In the
instance of an oil-producing well, for example, a gas cone may
cause an in-flow of gas into the wellbore that could significantly
reduce oil production. Similarly, a water cone may cause an in-flow
of water into the oil production flow that reduces the amount and
quality of the produced oil.
[0005] Accordingly, it is desired to provide even drainage across a
production zone and/or the ability to selectively close off or
reduce in-flow within production zones experiencing an undesirable
influx of water and/or gas. In other words, it would additionally
be desirable to discover an apparatus and method which could
improve the control of unwanted water production from subsurface
formations.
SUMMARY
[0006] There is provided in one non-limiting embodiment a wellbore
device for controlling a flow of a fluid through a flow path
therein. The wellbore device includes a container comprising a flow
path and a consolidated water sensitive porous medium (WSPM) packed
within the flow path of the wellbore device container. In turn, the
WSPM includes solid particles and at least one water hydrolyzable
polymer at least partially coated on the solid particles.
[0007] There is additionally provided in one non-restrictive
version, a method of constructing a wellbore device for controlling
a flow of a fluid through a flow path in the wellbore device, where
the method involves mixing solid particles with at least one water
hydrolyzable polymer in the presence of a fluid that may be water
or brine to give a mixture. The method further includes at least
partially drying the mixture. Additionally the method involves
packing the at least partially dried mixture into the flow path of
the container of the wellbore device to form a consolidated water
sensitive porous medium (WSPM).
[0008] There is also provided, in another non-limiting form, a
method for controlling a flow of a fluid through a flow path in a
wellbore device in a wellbore. The method involves flowing the
fluid through the flowpath in the wellbore device and controlling a
resistance to flow of the fluid through the flow path whereby:
resistance to flow increases as water content of the fluid
increases, and resistance to flow decreases as water content of the
fluid decreases. The wellbore device used includes a container
(which may be coextensive therewith) comprising the flow path and a
consolidated water sensitive porous medium (WSPM) packed within the
flow path of the wellbore device container. In turn the WSPM
includes solid particles and at least one water hydrolyzable
polymer at least partially coated on the solid particles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic illustration of water sensitive porous
media (WSPM) installed inside a wellbore to control the production
of water;
[0010] FIGS. 2A and 2B are schematic illustrations of different
water cuts generating different flow resistance when flowing
through a WSPM as a result of different degrees of polymer chain
activation (expansion);
[0011] FIG. 3 is a graph of the pressure differential of WSPM
(crosslinked VF-1 copolymer coated on 20-60 mesh (850-250 micron)
HSP.RTM. proppant) at 200.degree. F. (93.degree. C.) with diesel
and simulated formation brine (SFB);
[0012] FIG. 4 is a graph of a pressure drop response for different
water cut fluids flowing through WSPM at 200.degree. F. (93.degree.
C.);
[0013] FIG. 5 is a microphotograph of 20/40 mesh (850/425 micron)
HSP ceramic proppant before polymer coating; and
[0014] FIG. 6 is a microphotograph of 20/40 mesh (850/425 micron)
HSP ceramic proppant after polymer coating.
DETAILED DESCRIPTION
[0015] A method has been discovered for building a water sensitive
porous medium (WSPM) to control downhole water production through a
flowpath in a wellbore device installed inside of a wellbore. The
WSPM may be constructed of water-soluble or water-hydrolyzable,
high molecular weight polymers which are coated on solid particles,
such as sand, glass beads, and ceramic proppants. The coated
particles are packed under high pressure to form a consolidated
homogenous and high porosity porous medium within a container of a
wellbore device. The container and the wellbore device may be
separate structures, where the container is part of the wellbore
device, or the container and the wellbore device may be the same
and coextensive. After the polymers are fully hydrolyzed in water
or brine, the polymers may be optionally crosslinked with
crosslinking agents. The solid particles may be mixed with the
polymer solution, e.g. in a blender or mixer, at a particular
ratio.
[0016] As a blender or mixer is continuous stirring the mixture of
solid particles and polymer solution, blowing ambient air, hot air,
nitrogen, or vacuuming is applied to the mixture to at least
partially or completely dry the polymer. The polymer coated
particles are loaded into a container to pack into consolidated
porous medium at high pressure. The packed container, as part of a
downhole tool, is installed in a wellbore. When formation water is
flowed through the WSPM interstitial flow channels, the coated
polymers extend their polymer chains into the pore flow channels,
resulting in increased fluid flow resistance. Conversely, when oil
flows through the WSPM, the polymer chains shrink back to open the
flow channels wider for the desired oil flow. This process has been
demonstrated to be repeatable and reversible as water/oil fluid
composition varies.
[0017] When water mixed with oil flows through the WSPM, the
magnitude in pressure drop across the flow channels depends on the
percentage of water in the mixture (water/oil ratio, or WOR).
Higher water cuts result in higher resulting pressure drops. As
will be discussed, lab testing data has confirmed that pressure
drops across WSPM change with water percentage of flowing through
fluids.
[0018] More specifically, the production of unwanted subterranean
formation water may be prevented, controlled or inhibited by a
method involving treating particles with high molecular weight,
water-hydrolyzable polymers, and incorporating the particles into a
water sensitive porous medium (WSPM) in a wellbore device placed
within the wellbore. The polymer-coated particles are introduced
into a container of a wellbore device under high pressure to form a
consolidated WSPM in the device before its introduction
downhole.
[0019] Generally, the relatively high molecular weight polymers
that have components or functional groups that anchor, affiliate or
attach onto the surface of the solid particles. The polymers are
hydrophilic and/or hydrolyzable meaning they swell or expand in
physical size upon contact with water. The average particle size of
the particles may range from about 10 mesh to about 100 mesh (from
about 2000 microns to about 150 microns). Alternatively, the
average particle size of the particles may range from about 20 mesh
independently to about 60 mesh (from about 840 microns to about 250
microns); where the term "independently" means that any lower
threshold may be combined with any upper threshold. Thus, it should
be understood that the solid particles which serve as a substrate
to the water hydrolyzable polymer are relatively small, particulate
matter, but should not be confused with atomic particles or
subatomic particles.
[0020] The particles may be any of a wide variety of solid
particulate material; suitable materials include, but are not
necessarily limited to, sand, glass beads, ceramic beads, metal
beads, bauxite grains, walnut shell fragments, aluminum pellets,
nylon pellets and combinations thereof, including conventional
proppants and gravel, and, including proppants and gravel of
to-be-developed materials. Proppants are known in the oilfield as
sized particles typically mixed with fracturing fluids to hold open
fractures after a hydraulic fracturing treatment. Proppants are
sorted for size and sphericity to provide an effective conduit for
the production of oil and/or gas from the reservoir to the
wellbore. "Gravel" has a particular meaning in the oilfield
relating to particles of a specific size or specific size range
which are placed between a screen that is positioned in the
wellbore and the surrounding annulus. The size of the gravel is
selected to prevent the passage of sand from the formation through
the gravel pack.
[0021] Further, the solid particles, e.g. proppants or gravel, may
suitably be a variety of materials including, but not necessarily
limited to, sand (the most common component of which is silica,
i.e. silicon dioxide, SiO.sub.2), glass beads, ceramic beads, metal
beads, bauxite grains, walnut shell fragments, aluminum pellets,
nylon pellets and combinations thereof.
[0022] The particles may be coated by a method that involves at
least partially hydrolyzing the polymer in a liquid including, but
not necessarily limited to, water, brine, glycol, ethanol and
mixtures thereof. The particles are then intimately mixed or
contacted with the liquid containing the polymer to contact the
surfaces of the particles with the polymer. The liquid is then at
least partially vaporized or evaporated through vacuum, or the use
of heat and/or contact with a dry gas such as air, nitrogen, or the
like. The coating method may be conducted at a temperature between
ambient up to about 200.degree. F. (about 93.degree. C.), to
facilitate quick drying of the coating. It may not be necessary in
some embodiments to completely dry the coating.
[0023] The loading of the polymers may be a ratio of weight of
solid particles to weight of dry water hydrolyzable polymer ranging
from about 10,000:1 to about 10:1; alternatively ranging from about
500:1 independently to about 25:1. The solid particles should be at
least partially coated by the polymer; that is, while it is
desirable to completely coat the solid particles with the polymer,
the method and apparatus may still be considered successful if the
particles are at least partially coated to the extent the WSPM
functions effectively for the purposes noted herein.
[0024] The high pressure used to pack the water hydrolyzable
polymer coated particles into the container of the wellbore device
through which the flow path exists may range from about 50 to about
2000 psi (about 0.3 to about 13.8 MPa), alternatively from about
100 independently to about 1000 psi (about 0.7 to about 6.9
MPa).
[0025] The WSPM placed in the wellbore will control unwanted
formation water flowing through the wellbore while not adversely
affecting the flow of oil and gas. When water flows into the WSPM,
the polymers anchored on the solid particles expand to reduce the
water flow channel and increase the resistance to water flow. The
polymers may be understood to interact chemically, ionically or
mechanically with a component of the produced or in-flowing
formation fluids, e.g. water molecules. This desired response may
be variously described as resistance, permeability, impedance,
etc., where the flow of hydrocarbons (e.g. oil and gas) is
desirable, but the flow of water is not. This interaction varies
the resistance to flow across the flow path of the wellbore device.
When oil and/or gas flow through this special porous media, the
polymers shrink to open the flow channel for oil and/or gas flow.
The pre-treated particles, (e.g. proppants) are expected to form
homogeneous porous media with the polymer uniformly distributed in
the media to increase the efficiency of the polymer controlling
unwanted water production.
[0026] In more detail, suitable water hydrolyzable polymers include
those having a weight average molecular weight greater than
100,000. Suitable, more specific examples of water hydrolyzable
polymers include, but are not necessarily limited to, homopolymers
and copolymers of acrylamide, sulfonated or quaternized
homopolymers and copolymers of acrylamide, polyvinylalcohols,
polysiloxanes, hydrophilic natural gum polymers and chemically
modified derivatives thereof. Crosslinked versions of these
polymers may also be suitable, including but not necessarily
limited to, crosslinked homopolymers and copolymers of acrylamide,
crosslinked sulfonated or quaternized homopolymers and copolymers
of acrylamide, crosslinked polyvinylalcohols, crosslinked
polysiloxanes, crosslinked hydrophilic natural gum polymers and
chemically modified derivatives thereof. Further specific examples
of suitable water hydrolyzable polymers include, but are not
necessarily limited to, copolymers having a hydrophilic monomeric
unit, where the hydrophilic monomeric unit is selected from the
group consisting of ammonium and alkali metal salt of
acrylamidomethylpropanesulfonic acid (AMPS), a first anchoring
monomeric unit based on N-vinylformamide and a filler monomeric
unit, where the filler monomeric unit is selected from the group
consisting of acrylamide and methylacrylamide. Additional suitable
water hydrolyzable polymers include, but are not necessarily
limited to, copolymers of vinylamide monomers and monomers
containing ammonium or quaternary ammonium moieties, copolymers of
vinylamide monomers and monomers comprising vinylcarboxylic acid
monomers and/or vinylsulfonic acid monomers, and salts thereof, and
these aforementioned copolymers further comprising a crosslinking
monomer selected from the group consisting of bis-acrylamide,
diallylamine, N,N-diallylacrylamide, divinyloxyethane,
divinyldimethylsilane.
[0027] In an optional embodiment, when the polymers are fully or
essentially completely hydrolyzed, they may be cross-linked to
increase their molecular weight. Suitable crosslinking agents
include, but are not necessarily limited to, aluminum, boron,
chromium, zirconium, titanium, and other inorganic based and
organic based crosslinking agents and other conventional
crosslinking agents.
[0028] These polymers are sometimes referred to as relative
permeability modifiers (RPMs) and more information about RPMs
suitable to be of use in the method and compositions described
herein may be found in U.S. Pat. Nos. 5,735,349; 6,228,812;
7,008,908; 7,207,386 and 7,398,825, all of which are incorporated
by reference herein in their entirety.
[0029] Shown in FIG. 1 is a schematic illustration of an oil well
10 having a wellbore 12, which happens to be vertical in part and
horizontal in part, in a subterranean formation 14 that contains
both oil and water. Water sensitive porous media (WSPM) within
wellbore devices 16 have been installed at four locations between
packers 18 along the horizontal section of the wellbore 12 to
control the production of water. The flow of oil from the formation
14 into the wellbore 12 is schematically indicated by black arrows
20, whereas the flow of water is schematically indicated by gray
arrows 22. The flow of oil 20 is uninhibited by the WSPM due to the
lack of resistance of the unhydrolyzed polymer, whereas the flow of
water is inhibited by the increased resistance of the hydrolyzed
polymer, as indicated by the lower water flow at small gray arrows
24.
[0030] Shown in FIG. 2 is a schematic illustration of different
water cuts generating different flow resistance when flowing
through a WSPM 16 as a result of different degrees of polymer chain
activation (expansion). As previously discussed, the WSPM 16
includes solid particles 30 having water hydrolyzable polymers 32
at least partially coated thereon or adhered thereto. The water
droplets are schematically represented by gray circles 34 and the
oil droplets are schematically represented by black circles 36.
FIG. 2A schematically illustrates the WSPM 16 where a 25% water cut
flows in the direction shown (left to right) where the relatively
low amount of water droplets 34 cause a relatively small amount of
the polymer 32 to swell, enlarge or hydrolyze increasing resistance
to flow. FIG. 2B schematically illustrates the WSPM 16 where a
larger 50% water cut flows in the direction shown (left to right)
where the relatively equal amount of water droplets 34 compared to
the oil droplets 36 cause a relatively larger amount of the polymer
32 to swell, enlarge or hydrolyze further increasing resistance to
flow, as compared with FIG. 2A.
[0031] The invention will now be illustrated with respect to
certain examples which are not intended to limit the invention in
any way but simply to further illustrated it in certain specific
embodiments.
EXAMPLES
[0032] FIG. 5 is a microphotograph of 20/40 mesh (850/425 micron)
HSP.RTM. ceramic proppant before polymer coating. HSP proppant is
available from Carbo Ceramics. FIG. 6 is a microphotograph of the
same 20/40 mesh (850/425 micron) HSP ceramic proppant after polymer
coating. It may be seen that each proppant particle in FIG. 6 is
fully coated and bonded by the polymer using the coating method
described.
[0033] One non-limiting packing procedure for building a WSPM as a
water sensitive flow channel (WSFC) is set out in Table I. The
procedure involves packing polymer coated proppants into 1 inch
(2.5 cm) ID and 12 inch (30 cm) long stainless steel tube with both
end caps forming a uniform porous medium.
TABLE-US-00001 TABLE I Packing Procedure 1) The stainless steel
tube (container, simulating a wellbore device) is affixed on one
end with an end cap; a 100 mesh (150 micron) stainless screen is
laid inside the end cap to hold the polymer coated proppants; 2)
The stainless steel tube is placed into a compressor with open end
up; 3) One spoon of polymer coated proppants (about 5 grams) is
loaded inside of the tube, and a 0.97 inch (2.5) ID and 18
inch-long (45.7 cm) alumina rod is put against the proppants inside
of the tube; 4) 1200 pound force from a compressor is loaded onto
the alumina rod to compress the polymer coated proppants into a
consolidated porous medium; 5) Steps 3) and 4) are repeated until
the length of the porous medium reaches desired porous medium
length; 6) Another 100 mesh (150 micron) stainless screen is
affixed on the top of the stainless steel tube; 7) Stainless steel
spacers are added into the tube if there is any open space inside
of the tube; and 8) The top end cap was tightened and the tube is
ready for testing.
[0034] FIG. 3 is a graph of the pressure differential of
crosslinked VF-1 copolymer coated on 20-60 mesh (850-250 micron)
HSP proppant at 200.degree. F. (93.degree. C.) with diesel and
simulated formation brine (SFB). VF-1 is a cross-linked
vinylamide-vinylsulfonate copolymer. The HSP proppants were coated
with the VF-1 polymer as described above. The polymer loading was
0.4% bw (by weight) of the proppant weight. FIG. 3 is a response
test graph showing that the pressure differential of the
polymer-coated proppant WSPM placed inside of a 12-inch long,
1-inch ID stainless steel tube (about 30 cm long by about 2.5 cm
ID) changes when pumping with oil (diesel in this Example) relative
to pumping with formation water (Simulated Formation Brine or SFB)
flowing through the pack. This graph demonstrates that the pack
exhibits high flow resistance for water and low flow resistance for
oil.
[0035] FIG. 4 is a graph of a pressure drop response for different
water cut fluids flowing through a WSPM at 200.degree. F.
(93.degree. C.). The fluids were blends of brine and diesel. With
increasing amounts of water (greater water cut percentage), the
higher the pressure drop. The WSPM was made from VF-1 coated 50-60
mesh (297 to 250 micron) ceramic proppants with polymer loading
0.4%. Different water cuts are marked on FIG. 4.
[0036] In the foregoing specification, the invention has been
described with reference to specific embodiments thereof, and has
been demonstrated as effective in providing methods for inhibiting
and controlling water flow through wellbores, particularly wellbore
devices having flow paths containing solid particles coated with a
water hydrolyzable polymer. However, it will be evident that
various modifications and changes can be made thereto without
departing from the broader spirit or scope of the invention as set
forth in the appended claims. Accordingly, the specification is to
be regarded in an illustrative rather than a restrictive sense. For
example, specific combinations of solid particles, water
hydrolyzable polymers, wellbore devices and other components
falling within the claimed parameters, but not specifically
identified or tried in a particular composition or method, are
expected to be within the scope of this invention. Further, it is
expected that the components and proportions of the solid particles
and polymers and steps of constructing the wellbore devices may
change somewhat from wellbore device to another and still
accomplish the stated purposes and goals of the methods described
herein. For example, the assembly methods may use different
pressures and additional or different steps than those exemplified
herein.
[0037] The words "comprising" and "comprises" as used throughout
the claims is interpreted "including but not limited to".
[0038] The present invention may suitably comprise, consist or
consist essentially of the elements disclosed and may be practiced
in the absence of an element not disclosed. For instance, a
wellbore device for controlling a flow of a fluid through a flow
path may consist of or consist essentially of a container
comprising a flow path and a consolidated water sensitive porous
medium (WSPM) packed within the flow path of the wellbore device
container, where the WSPM consists of or consists essentially of
solid particles and at least one water hydrolyzable polymer at
least partially coated on the solid particles.
* * * * *