U.S. patent application number 11/180489 was filed with the patent office on 2007-01-18 for apparatus and method for reducing water production from a hydrocarbon producing well.
Invention is credited to Travis T. JR. Hailey, John Horgan.
Application Number | 20070012444 11/180489 |
Document ID | / |
Family ID | 37660619 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070012444 |
Kind Code |
A1 |
Horgan; John ; et
al. |
January 18, 2007 |
Apparatus and method for reducing water production from a
hydrocarbon producing well
Abstract
A filtering apparatus for use in a hydrocarbon producing well
for reducing water production therein includes a filtering medium
treated with a relative permeability modifier such that the
relative permeability modifier reduces the permeability of the
filtering medium if the relative permeability modifier contacts
water production. The relative permeability modifier may be used to
treat a metal portion of the filtering medium in the case of a wire
wrap screen or a wire mesh screen or may be use treat a metal
portion or the prepacked component of a prepacked screen. The
relative permeability modifier may be a polymer of at least one
hydrophilic monomer and at least one hydrophobically modified
hydrophilic monomer, a hydrophobically modified polymer, a
hydrophobically modified water-soluble polymer, hydrophobically
modified copolymers thereof or the like.
Inventors: |
Horgan; John; (Cypress,
TX) ; Hailey; Travis T. JR.; (Sugar Land,
TX) |
Correspondence
Address: |
Lawrence R. Youst;Danamraj & Youst, p.c.
Premier Place, Suite 1450
5910 North Central Expressway
Dallas
TX
75206
US
|
Family ID: |
37660619 |
Appl. No.: |
11/180489 |
Filed: |
July 12, 2005 |
Current U.S.
Class: |
166/278 ;
166/227 |
Current CPC
Class: |
E21B 43/088
20130101 |
Class at
Publication: |
166/278 ;
166/227 |
International
Class: |
E21B 43/00 20060101
E21B043/00; E21B 33/13 20060101 E21B033/13 |
Claims
1. A filtering apparatus for use in a hydrocarbon producing well,
the filtering apparatus comprising: a filtering medium treated with
a relative permeability modifier; and wherein the relative
permeability modifier reduces the permeability of the filtering
medium if the relative permeability modifier contacts water
production.
2. The filtering apparatus as recited in claim 1 wherein the
filtering medium is a sand control screen selected from the group
consisting of a wire wrap screen, a prepacked screen and a wire
mesh screen.
3. The filtering apparatus as recited in claim 1 wherein the
relative permeability modifier is used to treat at least one of a
metal portion of the filtering medium and a prepacked component of
the filtering medium.
4. The filtering apparatus as recited in claim 1 wherein the
relative permeability modifier is selected from the group
consisting of a polymer of at least one hydrophilic monomer and at
least one hydrophobically modified hydrophilic monomer, a
hydrophobically modified polymer, a hydrophobically modified
water-soluble polymer and hydrophobically modified copolymers
thereof.
5. The filtering apparatus as recited in claim 1 wherein the
relative permeability modifier is selected from the group
consisting of a polymer of at least one of acrylamide,
2-acrylamido-2-methyl propane sulfonic acid,
N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl
methacrylate, acrylic acid, dimethylaminopropylmethacrylamide,
trimethylammoniumethyl methacrylate chloride, methacrylamide, and
hydroxyethyl acrylate combined with at least one of alkyl
acrylates, alkyl methacrylates, alkyl acrylamides, alkyl
methacrylamides, alkyl dimethylammoniumethyl methacrylate bromide,
alkyl dimethylammoniumethyl methacrylate chloride, alkyl
dimethylammoniumethyl methacrylate iodide, alkyl dimethylammonium
propylmethacrylamide bromide, alkyl dimethylammonium
propylmethacrylamide chloride and alkyl dimethylammonium
propylmethacrylamide iodide.
6. The filtering apparatus as recited in claim 1 wherein the
relative permeability modifier is selected from the group
consisting of hydrophobically modified polydimethylaminoethyl
methacrylate, hydrophobically modified polyacrylamide and
hydrophobically modified copolymers of dimethylaminoethyl
methacrylate and vinyl pyrollidone.
7. A method for reducing water production in a hydrocarbon
producing well, the method comprising the steps of: treating a
filtering medium with a relative permeability modifier; disposing
the filtering medium proximate a production zone of the well;
producing fluids from the production zone; and reducing the
permeability of the filtering medium if the relative permeability
modifier contacts water production.
8. The method as recited in claim 7 wherein the step of treating a
filtering medium with a relative permeability modifier further
comprises treating a sand control screen.
9. The method as recited in claim 7 wherein the step of treating a
filtering medium with a relative permeability modifier further
comprises treating at least one of a metal portion of the filtering
medium and a prepacked component of the filtering medium.
10. The method as recited in claim 7 wherein the step of treating a
filtering medium with a relative permeability modifier further
comprises treating the filter medium with a relative permeability
modifier selected from the group consisting of a polymer of at
least one hydrophilic monomer and at least one hydrophobically
modified hydrophilic monomer, a hydrophobically modified polymer, a
hydrophobically modified water-soluble polymer and hydrophobically
modified copolymers thereof.
11. The method as recited in claim 7 wherein the step of treating a
filtering medium with a relative permeability modifier further
comprises treating the filter medium with a relative permeability
modifier selected from the group consisting of a polymer of at
least one of acrylamide, 2-acrylamido-2-methyl propane sulfonic
acid, N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl
methacrylate, acrylic acid, dimethylaminopropylmethacrylamide,
trimethylammoniumethyl methacrylate chloride, methacrylamide, and
hydroxyethyl acrylate combined with at least one of alkyl
acrylates, alkyl methacrylates, alkyl acrylamides, alkyl
methacrylamides, alkyl dimethylammoniumethyl methacrylate bromide,
alkyl dimethylammoniumethyl methacrylate chloride, alkyl
dimethylammoniumethyl methacrylate iodide, alkyl dimethylammonium
propylmethacrylamide bromide, alkyl dimethylammonium
propylmethacrylamide chloride and alkyl dimethylammonium
propylmethacrylamide iodide.
12. The method as recited in claim 7 wherein the step of treating a
filtering medium with a relative permeability modifier further
comprises treating the filter medium with a relative permeability
modifier selected from the group consisting of hydrophobically
modified polydimethylaminoethyl methacrylate, hydrophobically
modified polyacrylamide and hydrophobically modified copolymers of
dimethylaminoethyl methacrylate and vinyl pyrollidone.
13. A completion system for use in a hydrocarbon producing well
having multiple production zones, the completion system comprising:
a production tubing string extending along a substantial length of
the well; an isolation and filtration subassembly disposed
proximate each of the production zones, each isolation and
filtration subassembly operably associated with the production
tubing string such that fluid from the respective production zones
is produced through one of the isolation and filtration
subassemblies into the production tubing string, each isolation and
filtration subassembly providing at least substantial zonal
isolation of one of the production zones; and wherein at least one
of the isolation and filtration subassemblies includes at least one
filtering medium treated with a relative permeability modifier such
that the relative permeability modifier reduces the permeability of
the associated filtering medium if the associated filtering medium
contacts water production, thereby reducing the production of water
from the associated production zone.
14. The completion system as recited in claim 13 wherein each
isolation and filtration subassembly further comprise a pair of
annular barriers and a sand control screen.
15. The completion system as recited in claim 14 wherein the
annular barriers are selected from the group consisting of
mechanical set packers, hydrostatic set packers, hydraulic set
packers, differential set packers, inflation set packers and
swelling elastomer set packers.
16. The completion system as recited in claim 13 wherein the
relative permeability modifier is used to treat at least one of a
metal portion of the filtering medium and a prepacked component of
the filtering medium.
17. The completion system as recited in claim 13 wherein each
isolation and filtration subassembly provides zonal isolation of
one of the production zones.
18. The completion system as recited in claim 13 wherein the
relative permeability modifier is selected from the group
consisting of a polymer of at least one hydrophilic monomer and at
least one hydrophobically modified hydrophilic monomer, a
hydrophobically modified polymer, a hydrophobically modified
water-soluble polymer and hydrophobically modified copolymers
thereof.
19. The completion system as recited in claim 13 wherein the
relative permeability modifier is selected from the group
consisting of a polymer of at least one of acrylamide,
2-acrylamido-2-methyl propane sulfonic acid,
N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl
methacrylate, acrylic acid, dimethylaminopropylmethacrylamide,
trimethylammoniumethyl methacrylate chloride, methacrylamide, and
hydroxyethyl acrylate combined with at least one of alkyl
acrylates, alkyl methacrylates, alkyl acrylamides, alkyl
methacrylamides, alkyl dimethylammoniumethyl methacrylate bromide,
alkyl dimethylammoniumethyl methacrylate chloride, alkyl
dimethylammoniumethyl methacrylate iodide, alkyl dimethylammonium
propylmethacrylamide bromide, alkyl dimethylammonium
propylmethacrylamide chloride and alkyl dimethylammonium
propylmethacrylamide iodide.
20. The completion system as recited in claim 13 wherein the
relative permeability modifier is selected from the group
consisting of hydrophobically modified polydimethylaminoethyl
methacrylate, hydrophobically modified polyacrylamide and
hydrophobically modified copolymers of dimethylaminoethyl
methacrylate and vinyl pyrollidone.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates, in general, to reducing water
production from a hydrocarbon producing well and, in particular, to
treating a filtering medium with a relative permeability modifier
to reduce the permeability of the filtering medium upon contact
with water production.
BACKGROUND OF THE INVENTION
[0002] Without limiting the scope of the present invention, its
background will be described with reference to a subterranean
hydrocarbon bearing formation that produces water, as an
example.
[0003] The production of water from subterranean hydrocarbon
bearing formations constitutes a major problem and expense in the
production of the hydrocarbons. While hydrocarbon producing wells
are usually completed in hydrocarbon producing formations, when the
formations contain layers of water and hydrocarbons or when there
are water producing zones near the hydrocarbon producing
formations, the higher mobility of the water often allows the water
to flow into the wellbores which penetrate the hydrocarbon
producing formations by way of natural fractures or high
permeability streaks. In the production of such wells, the ratio of
water to hydrocarbons recovered often becomes so high that the cost
of producing the water, separating it from the hydrocarbons and
disposing of it represents a significant economic loss.
[0004] In order to reduce the production of undesired water from
hydrocarbon producing formations, attempts have been made to use
aqueous polymer solutions containing cross-linking agents. These
aqueous polymer solutions have been pumped into the hydrocarbon
producing formations so that they enter water zones within and
adjacent to the formations and cross-link therein. The
cross-linking of the polymer solutions causes them to form stiff
gels which aid in stopping or reducing the flow of the undesired
water. While such aqueous polymer solutions have achieved some
degree of success, it has been found that they are not suitable for
formation treatments unless the polymer solution can be placed
solely in the offending water producing zone or zones. If a polymer
solution is allowed to gel within a hydrocarbon producing zone, the
cross-linked polymer gel will reduce or stop the flow of
hydrocarbons in addition to the flow of water. The selected
placement of a polymer solution in a producing formation requires
expensive, time-consuming zonal isolation placement technology. In
addition, even when a polymer solution is properly placed in a
water producing zone, the cross-linked gels often do not remain
stable in the zone due to thermal degradation or differences in the
adsorption characteristics of the polymer and associated
cross-linker.
[0005] More recently, chemicals referred to as relative
permeability modifiers have been utilized to decrease the
production of water with hydrocarbons. That is, water permeability
modifying chemicals, such as polyacrylamide, have been introduced
into formations producing hydrocarbon and water so that the
chemicals attach to adsorption sites on surfaces within the
porosity of the formations. The presence of the chemicals in the
formations has the effect of reducing the flow of water through the
treated formation while having a minimal affect on the flow of
hydrocarbons therethrough. The use of water permeability modifying
chemicals to decrease the production of water is considerably less
expensive than other techniques such as the above described
technique of blocking the flow of water with cross-linked polymers
and does not require expensive zonal isolation procedures. It has
been found, however, that the use of such hydrophilic water
permeability modifying chemicals has resulted in only small
reductions in water production and in some cases an unacceptable
level of reduction in hydrocarbon production.
[0006] Therefore, a need has arisen for an apparatus and method for
reducing water production from a hydrocarbon producing well. A need
has also arisen for such an apparatus and method that reduces the
water production without unacceptably reducing the production of
hydrocarbons. Further, need has arisen for such an apparatus and
method that reduces the water production without the need for
intervention.
SUMMARY OF THE INVENTION
[0007] The present invention disclosed herein comprises an
apparatus and method for reducing water production from a
hydrocarbon producing well. The apparatus and method of the present
invention are capable of achieving this reduction in water
production without unacceptably reducing the production of
hydrocarbons and without the need for intervention.
[0008] In one aspect, the present invention is directed to a
filtering apparatus that comprises a filtering medium treated with
a relative permeability modifier that reduces the permeability of
the filtering medium if the relative permeability modifier contacts
water production. In one embodiment, the filtering medium is a sand
control screen such as a wire wrap sand control screen, a prepacked
sand control screen, a wire mesh sand control screen or the like.
In any of these examples, the relative permeability modifier may be
used to treat a metal portion of the filtering medium.
Alternatively or additionally, in the case of a prepacked sand
control screen, the relative permeability modifier may be used to
treat the prepacked material of the sand control screen.
[0009] In one embodiment of the present invention, the relative
permeability modifier used to treat the filtering medium is
selected from the group consisting of a polymer of at least one
hydrophilic monomer and at least one hydrophobically modified
hydrophilic monomer, a hydrophobically modified polymer, a
hydrophobically modified water-soluble polymer and hydrophobically
modified copolymers thereof. For example, the relative permeability
modifier may be selected from the group consisting of a polymer of
at least one of acrylamide, 2-acrylamido-2-methyl propane sulfonic
acid, N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl
methacrylate, acrylic acid, dimethylaminopropylmethacrylamide,
trimethylammoniumethyl methacrylate chloride, methacrylamide, and
hydroxyethyl acrylate combined with at least one of alkyl
acrylates, alkyl methacrylates, alkyl acrylamides, alkyl
methacrylamides, alkyl dimethylammoniumethyl methacrylate bromide,
alkyl dimethylammoniumethyl methacrylate chloride, alkyl
dimethylammoniumethyl methacrylate iodide, alkyl dimethylammonium
propylmethacrylamide bromide, alkyl dimethylammonium
propylmethacrylamide chloride and alkyl dimethylammonium
propylmethacrylamide iodide. As another example, the relative
permeability modifier may be selected from the group consisting of
hydrophobically modified polydimethylaminoethyl methacrylate,
hydrophobically modified polyacrylamide and hydrophobically
modified copolymers of dimethylaminoethyl methacrylate and vinyl
pyrollidone.
[0010] In another aspect, the present invention is directed to a
method for reducing water production in a hydrocarbon producing
well. The method includes treating a filtering medium with a
relative permeability modifier, disposing the filtering medium
proximate a production zone of the well, producing fluids from the
production zone and reducing the permeability of the filtering
medium if the relative permeability modifier contacts water
production.
[0011] In a further aspect, the present invention is directed to a
completion system for use in a hydrocarbon producing well having
multiple production zones. The completion system comprises a
production tubing string extending along a substantial length of
the well and an isolation and filtration subassembly disposed
proximate each of the production zones. Each isolation and
filtration subassembly is operably associated with the production
tubing string such that fluid from the respective production zones
is produced through one of the isolation and filtration
subassemblies into the production tubing string. In addition, each
isolation and filtration subassembly provides substantial zonal
isolation of the respective production zones. The isolation and
filtration subassemblies include at least one filtering medium
treated with a relative permeability modifier such that the
relative permeability modifier reduces the permeability of the
associated filtering medium if the associated filtering medium
contacts water production, thereby reducing the production of water
from the associated production zone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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:
[0013] FIG. 1 is a schematic illustration of an offshore oil and
gas platform operating a completion system for reducing water
production from a hydrocarbon producing well of the present
invention;
[0014] FIG. 2 is partial cut away view of an apparatus for reducing
water production from a hydrocarbon producing well of the present
invention;
[0015] FIG. 3 is partial cut away view of an apparatus for reducing
water production from a hydrocarbon producing well of the present
invention;
[0016] FIG. 4 is partial cut away view of an apparatus for reducing
water production from a hydrocarbon producing well of the present
invention;
[0017] FIG. 5 is a schematic illustration of a completion system
for reducing water production from a cased hydrocarbon producing
well of the present invention; and
[0018] FIG. 6 is a schematic illustration of a completion system
for reducing water production from a horizontal, open hole
hydrocarbon producing well of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] 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.
[0020] Referring initially to FIG. 1, a completion system for
reducing water production from a hydrocarbon producing well is
being installed from an offshore oil and gas platform that is
schematically illustrated and generally designated 10. A
semi-submersible platform 12 is centered over a submerged oil and
gas formation 14 located below sea floor 16. A subsea conduit 18
extends from deck 20 of platform 12 to wellhead installation 22
including blowout preventers 24. Platform 12 has a hoisting
apparatus 26 and a derrick 28 for raising and lowering pipe strings
such as production tubing string 30.
[0021] A wellbore 32 extends through the various earth strata
including formation 14. A casing 34 is cemented within wellbore 32
by cement 36. Production tubing 30 includes various tools such as a
plurality of isolation and filtration subassemblies that are
disposed proximate formation 14 and divide formation 14 into a
plurality of isolated or substantially isolated production zones.
As illustrated, production zone 38 is defined by annular barriers
40, 42 and screen assembly 44, production zone 46 is defined by
annular barriers 42, 48 and screen assembly 50 and production zone
52 is defined by annular barriers 48, 54 and screen assembly 56.
Once production commences from formation 14, fluid may be produced
into production zone 38 via perforations 58, into production zone
46 via perforations 60 and into production zone 52 via perforations
62.
[0022] As explained in more detail below, the completion system of
the present invention is capable of reducing water production,
including any water produced with hydrocarbons from formation 14
such as salt water and brines, without reducing the production of
hydrocarbons and without the need for intervention. Specifically,
screen assemblies 44, 50, 56 have each been treated with a relative
permeability modifier that reduces the permeability of a screen
assembly 44, 50, 56 if that screen assembly 44, 50, 56 contacts
water production. Importantly, the relative permeability modifier
used in the present invention is substantially inert to
hydrocarbons such that the permeability of a screen assembly 44,
50, 56 is not adversely affected by hydrocarbon production. In
addition, the action of the relative permeability modifier is
initiated by contact with water production, thereby not requiring
intervention by field personnel.
[0023] Even though FIG. 1 depicts a vertical well, it should be
understood by those skilled in the art that the completion system
of the present invention is equally well-suited for use in deviated
wells, inclined wells or horizontal wells. Also, even though FIG. 1
depicts an offshore operation, it should be noted by one skilled in
the art that the completion system of the present invention is
equally well-suited for use in onshore operations. Further, even
though FIG. 1 depicts three production zones, it should be
understood by those skilled in the art that the completion system
of the present invention is equally well-suited for use with any
number of production zones whether those production zones are
adjacent to one another and sharing a common annular barrier, as
depicted, or separated from one another.
[0024] Referring now to FIG. 2, therein is depicted a partial cut
away view of a screen assembly for reducing water production from a
hydrocarbon producing well of the present invention that is
generally designated 100. Screen assembly 100 includes a base pipe
102 that has a plurality of openings 104 that allow the flow of
production fluids into the production tubing. The exact number,
size and shape of openings 104 are not critical to the present
invention, so long as sufficient area is provided for fluid
production and the integrity of base pipe 102 is maintained. Spaced
around base pipe 102 is a plurality of ribs 106. Ribs 106 are
generally symmetrically distributed about the axis of base pipe
102. Ribs 106 are depicted as having a cylindrical cross section,
however, it should be understood by one skilled in the art that
ribs 106 may alternatively have a rectangular or triangular cross
section or other suitable geometry. Additionally, it should be
understood by one skilled in the art that the exact number of ribs
106 will be dependent upon the diameter of base pipe 102 as well as
other design characteristics that are well known in the art.
[0025] Wrapped around ribs 106 is a screen wire 108. Screen wire
108 forms a plurality of turns, such as turn 110, turn 112 and turn
114. Between each of the turns is a gap through which formation
fluids flow. The number of turns and the gap between the turns are
determined based upon the characteristics of the formation from
which fluid is being produced and the amount expansion experienced
by the selected relative permeability modifier. Together, ribs 106
and screen wire 108 may form a screen jacket which is attached to
base pipe 102 by welding or other suitable techniques. As will be
recognized by those skilled in the art, screen assembly 100 may
typically be used in sand control operations wherein particulate
materials such as sand are produced during the production of
hydrocarbons from the well. Screen assembly 100 of the present
invention, however, is not only suitable for sand control
operations but is alternatively or additionally suitable for
reducing water production from the well. Specifically, as explained
in more detail below, screen wire 108 has been treated with a
relative permeability modifier which expands when it comes in
contact with water. As such, the gaps between the turns of screen
wire 108 are reduced or eliminated when the relative permeability
modifier is exposed to water which reduces the permeability of
screen assembly 100 and, in some embodiments, can effectively shut
off production from screen assembly 100.
[0026] Referring now to FIG. 3, therein is depicted a partial cut
away view of a screen assembly for reducing water production from a
hydrocarbon producing well of the present invention that is
generally designated 120. Screen assembly 120 includes a base pipe
122 that has a plurality of openings 124 which allow the flow of
production fluids into the production tubing. The exact number,
size and shape of openings 124 are not critical to the present
invention, so long as sufficient area is provided for fluid
production and the integrity of base pipe 120 is maintained.
[0027] Positioned around base pipe 122 is a fluid-porous,
particulate restricting, metal filter having a plurality of layers
of a wire mesh that are sintered or diffusion bonded together to
form a porous wire mesh screen 126. As should be understood by
those skilled in the art, screen 126 allows fluid flow therethrough
but prevent the flow of particulate materials of a predetermined
size from passing therethrough. The layers of wire mesh may include
drain layers that have a mesh size that is larger than the mesh
size of the filter layers. For example, a drain layer may
preferably be positioned as the outermost layer and the innermost
layer of wire mesh screen 126 with the filter layer or layers
positioned therebetween.
[0028] Positioned around screen 126 is a screen wrapper 128 that
has a plurality of openings 130 which allow the flow of production
fluids therethrough. The exact number, size and shape of openings
130 is not critical to the present invention, so long as sufficient
area is provided for fluid production and the integrity of screen
wrapper 128 is maintained. Typically, various sections of screen
126 and screen wrapper 128 are manufactured together as a unit by,
for example, sintering or diffusion bonding a number layers of wire
mesh that form screen 126 together with screen wrapper 128, then
rolling the unit into a tubular configuration. The two ends of the
tubular unit are then seam welded together. Several tubular units
of the screen and screen wrapper combination may then be placed
over each joint of base pipe 122 and secured thereto by welding or
other suitable technique.
[0029] As with screen assembly 100, screen assembly 120 of the
present invention is not only suitable for sand control operations
but is alternatively or additionally suitable for reducing water
production from the well. Specifically, as explained in more detail
below, wire mesh screen 126 has been treated with a relative
permeability modifier which expands when it comes in contact with
water. As such, when wire mesh screen 126 is exposed to water, the
permeability of screen assembly 120 is reduced and in some
embodiments, production through screen assembly 120 can be
effectively shut off.
[0030] Referring now to FIG. 4, therein is depicted a partial cut
away view of a screen assembly for reducing water production from a
hydrocarbon producing well of the present invention that is
generally designated 140. Screen assembly 140 includes a base pipe
142 that has a plurality of openings 144 that allow the flow of
production fluids into the production tubing. The exact number,
size and shape of openings 144 are not critical to the present
invention, so long as sufficient area is provided for fluid
production and the integrity of base pipe 142 is maintained. Spaced
around base pipe 142 is a plurality of ribs 146. Ribs 146 are
generally symmetrically distributed about the axis of base pipe
142. Ribs 146 are depicted as having a cylindrical cross section,
however, it should be understood by one skilled in the art that
ribs 146 may alternatively have a rectangular or triangular cross
section or other suitable geometry. Additionally, it should be
understood by one skilled in the art that the exact number of ribs
146 will be dependent upon the diameter of base pipe 142 as well as
other design characteristics that are well known in the art.
[0031] Wrapped around ribs 146 is a screen wire 148. Screen wire
148 forms a plurality of turns, such as turn 150, turn 152 and turn
154. Between each of the turns is a gap through which formation
fluids flow. The number of turns and the gap between the turns are
determined based upon the characteristics of the formation from
which fluid is being produced as well as other factors known to
those skilled in the art. Positioned around screen wire 148 is a
prepack sand 156 that may be a baked-resin of sand, gravel,
engineered proppants or other pack material that is highly
permeable to the flow of hydrocarbon fluids but blocks the flow of
the particulates carried in the hydrocarbon fluids. As should be
understood by one skilled in the art, the thickness of the layer of
prepack sand 156 and the size of the sand forming the layer of
prepack sand 156 is determined based upon the characteristic of the
particular implementation.
[0032] A plurality of ribs 158 is disposed within the exterior
portion of the layer of prepack sand 156. Ribs 158 are generally
symmetrically distributed about the axis of base pipe 142. Ribs 158
are depicted as having a cylindrical cross section, however, it
should be understood by one skilled in the art that ribs 158 may
alternatively have a rectangular or triangular cross section or
other suitable geometry. Additionally, it should be understood by
one skilled in the art that the exact number of ribs 158 will be
dependent upon the diameter of base pipe 142 as well as other
design characteristics that are well known in the art.
[0033] Wrapped around ribs 156 is a screen wire 160. Screen wire
160 forms a plurality of turns, such as turn 162, turn 164 and turn
166. Between each of the turns is a gap through which formation
fluids flow. The number of turns and the gap between the turns are
determined based upon the characteristics of the formation from
which fluid is being produced as well as other factor known to
those skilled in the art. Together, ribs 146, screen wire 148,
prepacked sand 156, ribs 158 and screen wire 160 may form a screen
jacket which is attached to base pipe 142 by welding or other
suitable techniques.
[0034] As will be recognized by those skilled in the art, screen
assembly 140 may typically be used in sand control operations
wherein particulate materials such as sand are produced during the
production of hydrocarbons from the well. Screen assembly 140 of
the present invention, however, is not only suitable for sand
control operations but is alternatively or additionally suitable
for reducing water production from the well. Specifically, as
explained in more detail below, one or more of screen wire 148,
prepacked sand 156 and screen wire 160 has been treated with a
relative permeability modifier which expands when it comes in
contact with water. As such, when a treated filtering medium is
exposed to water, the permeability of screen assembly 140 is
reduced and, in some embodiments, production through screen
assembly 140 can be effectively shut off.
[0035] As previously alluded to, the filtering media 108, 126, 148,
156, 160 of the above described screen assemblies 100, 120, 140 may
be treated with a relative permeability modifier such that the
permeability of the screen assemblies 100, 120, 140 can be reduced
if the filtering media 108, 126, 148, 156, 160 comes in contact
with water. As an example, the relative permeability modifier may
be comprised of a polymer made from a combination of at least one
hydrophilic monomer and at least one hydrophobically modified
hydrophilic monomer that attaches to the permeable sites on the
filtering media 108, 126, 148, 156, 160. The presence of the
polymer in the filtering media 108, 126, 148, 156, 160 reduces the
flow of water therethrough.
[0036] 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,
dimethylaminopropylmethacrylamide, trimethylammoniumethyl
methacrylate chloride, methacrylamide and hydroxyethyl acrylate. Of
these, acrylamide, 2-acrylamido-2-methyl propane sulfonic acid,
acrylic acid, dimethylaminoethyl methacrylate and vinyl pyrrolidone
are preferred.
[0037] 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. Of these,
octadecyldimethylammoniumethyl methacrylate bromide,
hexadecyldimethyl-ammoniumethyl methacrylate bromide,
hexadecyldimethylammoniumpropyl methacrylamide bromide,
2-ethylhexyl methacrylate and hexadecyl methacrylamide are
preferred.
[0038] 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 U.S.
Pat. No. 6,476,169 which is hereby incorporated by reference for
all purposes.
[0039] 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 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. Particularly suitable polymers having
molecular weights and mole ratios in the ranges set forth above
include, but are not limited to, an
acrylamide/octadecyldimethylammoniumethyl methacrylate bromide
copolymer, a dimethylaminoethyl
methacrylate/hexadecyldimethylammoniumethyl methacrylate bromide
copolymer, a dimethylaminoethyl methacrylate/vinyl
pyrrolidone/hexadecyldimethylammoniumethyl methacrylate bromide
terpolymer and an acrylamide/2-acrylamido-2-methyl propane sulfonic
acid/2-ethylhexyl methacrylate terpolymer. Of these, an
acrylamide/octadecyl dimethylammoniumethyl methacrylate bromide
copolymer having a mole ratio of hydrophilic monomer to
hydrophobically modified hydrophilic monomer of 96:4 is presently
preferred.
[0040] 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.
[0041] Referring next to FIG. 5, therein is depicted a completion
system for reducing water production from a substantially vertical
section of a hydrocarbon producing well of the present invention
that is generally designated 200. Completion system 200 is disposed
with cased wellbore 202 that traverses hydrocarbon bearing
subterranean formation 204. Completion system 200 includes a
production tubing 206 that extends from the surface to formation
204. Completion system 200 also includes a plurality of isolation
and filtration subassemblies disposed proximate formation 204
dividing formation 204 into a plurality of isolated or
substantially isolated production zones. As illustrated, production
zone 208 is defined by annular barriers 210, 212 and screen
assembly 214, production zone 216 is defined by annular barriers
212, 218 and screen assembly 220 and production zone 222 is defined
by annular barriers 218, 224 and screen assembly 226. Fluid
communication from formation 204 into production zones 208, 216,
222 is allowed, respectively, via perforations 228, 230, 232. In
the illustrated embodiment, screen assemblies 214, 220, 226 may
represent any of the screen assemblies discussed above or other
suitable type of screen assembly wherein the filtering medium is
treated with any of the relative permeability modifiers discussed
above or other suitable relative permeability modifier. In the
illustrated embodiment, annular barriers 210, 212, 218, 224 may
represent any suitable annular flow restriction means commonly
known in the art such as mechanical set packers, hydrostatic set
packers, hydraulic set packers, differential set packers, inflation
set packers, swelling elastomer set packers and the like.
[0042] In operation, completion system 200 allows for the
production of hydrocarbons from formation 204 into production
tubing 206 from each of the production zones 208, 216, 222. In the
event that water production occurs from formation 204 into one of
the production zones 208, 216, 222, the screen assembly associated
with that production zone will have a reduced permeability. For
example, if water encroachment occurs from the lower end of
formation 204, the produced water will first enter production zone
222. When the relative permeability modifier treating the filter
medium of screen assembly 226 is contacted by the water, the
relative permeability modifier swells to reduce the permeability of
screen assembly 226, which reduces and, in some embodiments,
eliminates water production into production tubing 206 through
screen assembly 226. In this example, the hydrocarbon production
into production zones 208, 216 is not affected by the water
production into production zone 222 and the resulting permeability
reduction of screen assembly 226. Over time as the water
encroachment continues, water production may commence in production
zone 216. When the relative permeability modifier treating the
filter medium of screen assembly 220 is contacted by the water, the
relative permeability modifier swells to reduce the permeability of
screen assembly 220, which reduces and, in some embodiments,
eliminates water production into production tubing 206 through
screen assembly 220. In the illustrated embodiment, the hydrocarbon
production into production zone 208 and any other production zone
uphole of production zone 208 are not affected by the water
production into production zone 216 and the resulting permeability
reduction of screen assembly 220.
[0043] This process may continue as the water progressively
encroaches into the upper production zones of the well, however,
the water being produced into production tubing 206 is minimized as
the water production in each successively encountered production
zone is reduced or eliminated. As should be recognized by those
skilled in the art, the greater the number of production zones in a
well using the completion system of the present invention, the
greater the control over the hydrocarbon to water production ratio.
In addition, it should be noted by those skilled in the art that
complete zonal isolation is not required with the present
invention, rather, in certain embodiments, annular barriers 210,
212, 218, 224 need only to provide a suitable restriction or
substantial isolation. For example, as long as suitable friction is
created to fluid flow from one zone to the next due to a long
distance, a small annular size or the like, water production into
production tubing 206 will be suitably minimized. Likewise, if the
various zones have been gravel packed, the particulate material
that forms the gravel pack can provide such friction against
inter-zonal fluid flow.
[0044] Also, it should be apparent to those skilled in the art that
the use of directional terms such as top, bottom, above, below,
upper, lower, upward, downward, etc. 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. As such, it is to be understood that the
downhole components described herein may be operated in vertical,
horizontal, inverted or inclined orientations without deviating
from the principles of the present invention.
[0045] For example, as best seen in FIG. 6, therein is depicted a
completion system for reducing water production from a
substantially horizontal section of a hydrocarbon producing well of
the present invention that is generally designated 240. Completion
system 240 is disposed within an open hole wellbore 242 that
traverses hydrocarbon bearing subterranean formation 244.
Completion system 240 includes an production tubing 246 that
extends from the surface to formation 244. Completion system 240
also includes a plurality of isolation and filtration subassemblies
disposed proximate formation 244 dividing formation 244 into a
plurality of isolated or substantially isolated production zones.
As illustrated, production zone 248 is defined by annular barriers
250, 252 and screen assembly 254, production zone 256 is defined by
annular barriers 252, 258 and screen assembly 260 and production
zone 262 is defined by annular barriers 258, 264 and screen
assembly 266. Screen assemblies 254, 260, 266 may represent any of
the screen assemblies discussed above or other suitable type of
screen assembly and preferably represent expandable screen
assemblies that are expanded downhole into contact with the
borehole, as illustrated. In addition, regardless of the type of
screen assembly, the filtering medium associated with screen
assemblies 254, 260, 266 is treated with any of the relative
permeability modifier discussed above or other suitable relative
permeability modifier. In the illustrated embodiment, annular
barriers 250, 252, 258, 264 may represent any suitable annular flow
restriction means commonly known in the art such as mechanical set
packers, hydrostatic set packers, hydraulic set packers,
differential set packers, inflation set packers, swelling elastomer
set packers and the like.
[0046] In operation, completion system 240 allows for the
production of hydrocarbons from formation 244 into production
tubing 246 from each of the production zones 248, 256, 252. In the
event that water production occurs from formation 244 into one of
the production zones 248, 256, 262, the screen assembly associated
with that production zone will have a reduced permeability. For
example, if water production occurs from production zone 256, when
the relative permeability modifier treating the filter medium of
screen assembly 260 is contacted by the water, the relative
permeability modifier swells to reduce the permeability of screen
assembly 260, which reduces and, in some embodiments, eliminates
water production into production tubing 246 through screen assembly
260. Likewise, if water production from production zone 248 occurs,
when the relative permeability modifier treating the filter medium
of screen assembly 254 is contacted by the water, the relative
permeability modifier swells to reduce the permeability of screen
assembly 254, which reduces and, in some embodiments, eliminates
water production into production tubing 246 through screen assembly
254. Further, if water production from production zone 262 occurs,
when the relative permeability modifier treating the filter medium
of screen assembly 266 is contacted by the water, the relative
permeability modifier swells to reduce the permeability of screen
assembly 266, which reduces and, in some embodiments, eliminates
water production into production tubing 246 through screen assembly
266.
[0047] The operation of each of the screen assembly 254, 260, 266
is independent of the others which allows for significant control
over the hydrocarbon to water production ratio. As such, the
hydrocarbon production into a production zone which is not
producing water is not affected by the water production into one of
the other production zones and the resulting permeability reduction
of the screen assembly in that production zone. Also, the greater
the number of isolated production zones in the well using the
completion system of the present invention, the greater the control
over the hydrocarbon to water production ratio. In addition, the
operation of each of the screen assembly 254, 260, 266 is in
response to contact with the water production and does not require
intervention by field personnel. In addition, it should be noted by
those skilled in the art that a complete fluid seal is not
required, rather, in certain embodiments, the annular barriers need
only to provide a suitable restriction or substantial isolation to
inter-zonal fluid flow.
[0048] 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.
* * * * *