U.S. patent application number 11/033005 was filed with the patent office on 2006-07-13 for methods of making and using sulfonated carboxylated polysaccharide gelling agents.
This patent application is currently assigned to Halliburton Energy Services, Inc.. Invention is credited to Robert E. JR. Hanes, Jim D. Weaver.
Application Number | 20060151172 11/033005 |
Document ID | / |
Family ID | 36190438 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060151172 |
Kind Code |
A1 |
Hanes; Robert E. JR. ; et
al. |
July 13, 2006 |
Methods of making and using sulfonated carboxylated polysaccharide
gelling agents
Abstract
One embodiment of the present invention provides a method of
treating a subterranean formation comprising: providing a treatment
fluid comprising a sulfonated polysaccharide gelling agent wherein
the sulfonated polysaccharide gelling agent is produced by reacting
a cyclic sultone with a polysaccharide; and, introducing the
treatment fluid into a portion of a subterranean formation. Another
embodiment provides a method of treating a subterranean formation,
comprising: providing a treatment fluid comprising a carboxylated
polysaccharide gelling agent wherein the carboxylated
polysaccharide gelling agent is produced by reacting a
polysaccharide with at least one of the following: a cyclic lactone
or a cyclic phosphonate acid; and introducing the treatment fluid
into a portion of a subterranean formation. Another embodiment
provides a method of derivatizing a polysaccharide comprising
reacting a polysaccharide with at least one of the following: a
cyclic sultone, a cyclic lactone, or a cyclic phosphonate acid.
Inventors: |
Hanes; Robert E. JR.;
(Oklahoma City, OK) ; Weaver; Jim D.; (Duncan,
OK) |
Correspondence
Address: |
Robert A. Kent
2600 S. 2nd Street
Duncan
OK
73536-0440
US
|
Assignee: |
Halliburton Energy Services,
Inc.
|
Family ID: |
36190438 |
Appl. No.: |
11/033005 |
Filed: |
January 11, 2005 |
Current U.S.
Class: |
166/300 ;
166/278; 166/305.1; 166/308.5; 507/211; 507/237; 507/238; 507/244;
507/257; 507/267; 507/269; 507/903 |
Current CPC
Class: |
C09K 8/68 20130101; C09K
8/685 20130101; C09K 8/90 20130101 |
Class at
Publication: |
166/300 ;
166/278; 166/305.1; 166/308.5; 507/211; 507/237; 507/238; 507/244;
507/257; 507/267; 507/269; 507/903 |
International
Class: |
E21B 43/25 20060101
E21B043/25; E21B 43/04 20060101 E21B043/04 |
Claims
1. A method of treating a subterranean formation comprising:
providing a treatment fluid comprising a sulfonated polysaccharide
gelling agent wherein the sulfonated polysaccharide gelling agent
is produced by reacting a cyclic sultone with a polysaccharide;
and, introducing the treatment fluid into a portion of a
subterranean formation.
2. The method of claim 1 wherein the cyclic sultone comprises at
least one of the following: 1,3-propylsultone, 1,4-butylsultone, a
derivative of 1,3-propylsultone, a derivative of 1,4-butylsultone,
or a derivative of a cyclic sultone.
3. The method of claim 1 wherein the cyclic sultone and
polysaccharide are reacted under alkaline solid phase
conditions.
4. The method of claim 1 wherein the cyclic sultone and
polysaccharide are reacted under alkaline aqueous conditions.
5. The method of claim 1 wherein the treatment fluid further
comprises a crosslinking agent and wherein the crosslinking agent
comprises at least one of: N,N'-methylenebisacrylamide, boric acid,
disodium octaborate tetrahydrate, sodium diborate, a pentaborate,
ulexite, colemanite, a compound that can supply zirconium IV ions,
a compound that can supply titanium IV ions, an aluminum compound,
an antimony compound; a chromium compound; an iron compound; a
copper compound; or a zinc compound.
6. The method of claim 1 wherein the treatment fluid further
comprises a gel stabilizer, gel breaker, fluid loss control
additive, clay stabilizer, or bactericide.
7. The method of claim 1 wherein the treatment fluid further
comprises particulates.
8. A method of treating a subterranean formation, comprising:
providing a treatment fluid comprising a carboxylated
polysaccharide gelling agent wherein the carboxylated
polysaccharide gelling agent is produced by reacting a
polysaccharide with at least one of the following: a cyclic lactone
or a cyclic phosphonate acid; and introducing the treatment fluid
into a portion of a subterranean formation.
9. The method of claim 8 wherein the cyclic lactone comprises
butyrolactone, .beta.-propiolactone, a derivative of butyrolactone,
a derivative of .beta.-propiolactone, or a derivative of a cyclic
lactone.
10. The method of claim 8 wherein the cyclic phosphonate acid
comprises 1,2-oxaphospholane, a phosphonate ester, or a derivative
of a cyclic phosphonic acid.
11. The method of claim 8 wherein the cyclic lactone and
polysaccharide are reacted under alkaline solid phase
conditions.
12. The method of claim 8 wherein the cyclic lactone and
polysaccharide are reacted under alkaline aqueous conditions.
13. The method of claim 8 wherein the treatment fluid further
comprises a crosslinking agent and wherein the crosslinking agent
comprises at least one of: N,N'-methylenebisacrylamide, boric acid,
disodium octaborate tetrahydrate, sodium diborate, a pentaborate,
ulexite, colemanite, a compound that can supply zirconium IV ions,
a compound that can supply titanium IV ions, an aluminum compound,
an antimony compound; a chromium compound; an iron compound; a
copper compound; or a zinc compound.
14. The method of claim 8 wherein the treatment fluid further
comprises a gel stabilizer, gel breaker, fluid loss control
additive, clay stabilizer, or bactericide.
15. The method of claim 8 wherein the treatment fluid further
comprises particulates.
16. A method of derivatizing a polysaccharide comprising reacting a
polysaccharide with at least one of the following: a cyclic
sultone, a cyclic lactone, or a cyclic phosphonate acid.
17. The method of claim 16 wherein the cyclic sultone comprises at
least one of the following: 1,3-propylsultone, 1,4-butylsultone, a
derivative of 1,3-propylsultone, a derivative of 1,4-butylsultone,
or a derivative of a cyclic sultone.
18. The method of claim 16 wherein the cyclic lactone comprises
butyrolactone, .beta.-propiolactone, a derivative of butyrolactone,
a derivative of .beta.-propiolactone, or a derivative of a cyclic
lactone.
19. The method of claim 16 wherein the cyclic phosphonate acid
comprises 1,2-oxaphospholane, a phosphonate ester, or a derivative
of a cyclic phosphonic acid.
20. The method of claim 16 wherein the reaction occurs under either
alkaline solid phase conditions or alkaline aqueous conditions.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to subterranean treatment
fluids comprising sulfonated or carboxylated polysaccharide gelling
agents and methods of using such treatment fluids.
[0002] Treatment fluids are used in a variety of operations
performed in oil and gas wells, including production stimulation
operations (such as fracturing) and well completion operations
(such as gravel packing). An example of a production stimulation
operation using a treatment fluid is hydraulic fracturing. That is,
a type of treatment fluid, referred to in the art as a fracturing
fluid, is pumped through a well bore into a subterranean zone to be
stimulated at a rate and pressure such that fractures are formed or
enhanced in a desired subterranean zone. The fracturing fluid is
generally a gel, emulsion, or foam that may comprise a particulate
material often referred to as proppant. When used, proppant is
deposited in the fracture and functions, inter alia, to hold the
fracture open while maintaining conductive channels through which
produced fluids can flow upon completion of the fracturing
treatment and release of the attendant hydraulic pressure.
[0003] An example of a well completion operation using a treatment
fluid is gravel packing. Gravel packing treatments are used, inter
alia, to reduce the migration of unconsolidated formation
particulates into the well bore. In gravel packing operations,
particulates, referred to in the art as gravel, are carried to a
portion of a well bore by a treatment fluid. That is, the
particulates are suspended in a treatment fluid, which may be
viscosified, and the treatment fluid is pumped into a well bore in
which the gravel pack is to be placed. As the particulates are
placed in the zone, the treatment fluid leaks off into the
subterranean zone and/or is returned to the surface. The resultant
gravel pack acts as a filter to separate formation solids from
produced fluids while permitting the produced fluids to flow into
and through the well bore. While screenless gravel packing
operations are becoming more common, traditional gravel pack
operations involve placing a gravel pack screen in the well bore
and packing the surrounding annulus between the screen and the well
bore with gravel designed to prevent the passage of formation
particulates through the pack with produced fluids, wherein the
well bore may be oriented from vertical to horizontal and may
extend from hundreds to thousands of feet.
[0004] In some situations the processes of hydraulic fracturing and
gravel packing are combined into a single treatment to provide both
stimulated production and an annular gravel pack. Such treatments
are often referred to as "frac pack" operations. In some cases the
treatments are completed with a gravel pack screen assembly in
place with the hydraulic fracturing treatment being pumped through
the annular space between the casing and screen. In this situation,
the hydraulic fracturing treatment ends in a screen-out condition
creating an annular gravel pack between the screen and casing. This
allows both the hydraulic fracturing treatment and gravel pack to
be placed in a single operation. In other cases the fracturing
treatment may be performed prior to installing the screen and
placing a gravel pack.
[0005] A variety of methods are used to create the viscosified
treatment fluids typically used in subterranean operation.
Generally, a polysaccharide or synthetic polymer gelling agent is
used to impart viscosity to the treatment fluid to, among other
things, enhance particulate transport and reduce fluid loss from
the treatment fluid into the formation. Frequently, a crosslinking
agent, such as a metallic compound, is also added to further
enhance the viscosity of the treatment fluid by coupling, or
"crosslinking," gelling agent molecules. One class of gelling
agents employed in hydrocarbon production is sulfonated and
carboxylated polysaccharides, which provide unique properties for
crosslinking at higher temperatures and tolerate higher brine
concentrations in source waters. Previous sulfonation or
carboxylation processes typically involved reacting polysaccharides
with alkyl halides and pendant sulfonates or carboxylates,
respectively, under alkaline aqueous conditions. However, these
reactions have been inhibited by the fact that pendant sulfonates
or carboxylates decompose under aqueous conditions, often before
they react with the polysaccharides. Hence, the sulfonation or
carboxylation reactions suffered from low yields, low degrees of
substitution, and a lack of consistency in reaction products from
batch to batch. These problems limit the commercial viability of
sulfonated or carboxylated gelling agents in treatment fluids.
SUMMARY OF THE INVENTION
[0006] The present invention relates to subterranean treatment
fluids comprising sulfonated or carboxylated polysaccharide gelling
agents and methods of using such treatment fluids.
[0007] One embodiment of the present invention provides a method of
treating a subterranean formation comprising: providing a treatment
fluid comprising a sulfonated polysaccharide gelling agent wherein
the sulfonated polysaccharide gelling agent is produced by reacting
a cyclic sultone with a polysaccharide; and, introducing the
treatment fluid into a portion of a subterranean formation.
[0008] Another embodiment of the present invention provides a
method of treating a subterranean formation, comprising: providing
a treatment fluid comprising a carboxylated polysaccharide gelling
agent wherein the carboxylated polysaccharide gelling agent is
produced by reacting a polysaccharide with at least one of the
following: a cyclic lactone or a cyclic phosphonate acid; and
introducing the treatment fluid into a portion of a subterranean
formation.
[0009] Another embodiment of the present invention provides a
method of derivatizing a polysaccharide comprising reacting a
polysaccharide with at least one of the following: a cyclic
sultone, a cyclic lactone, or a cyclic phosphonate acid.
[0010] The features and advantages of the present invention will be
readily apparent to those skilled in the art upon a reading of the
description of the preferred embodiments that follows.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 shows the results of a .sup.13C NMR DEPT spectroscopy
test run on a sulfonated gelling agent of the present
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] The present invention relates to subterranean treatment
fluids comprising sulfonated or carboxylated polysaccharide gelling
agents and methods of using such treatment fluids.
[0013] In accordance with the present invention, a sulfonated or
carboxylated polysaccharide gelling agent may be used to increase
the viscosity of a treatment fluid. Generally, these gelling agents
are produced by reacting a polysaccharide with a cyclic sultone or
lactone, respectively, in a ring-opening reaction to sulfonate or
carboxylate the polysaccharide. Such sulfonated or carboxylated
polysaccharides may be crosslinked at higher temperatures and may
tolerate higher brine levels than their non-sulfonated or
non-carboxylated counterparts and thus they are useful in a variety
of treatment fluids. Furthermore, sulfonation and carboxylation via
ring-opening reactions may offer greater yields and higher degrees
of substitution that previous sulfonation or carboxylation
methods.
[0014] Generally, any form of an aqueous treatment fluid suitable
for a use in a subterranean operation such as fracturing or gravel
packing may be used in accordance with the teachings of the present
invention, including aqueous gels, foams, and emulsions. Suitable
aqueous gels are generally comprised of water and one or more
gelling agents. The emulsions can be comprised of two immiscible
liquids such as an aqueous gelled liquid and a liquefied, normally
gaseous fluid, such as nitrogen. In exemplary embodiments of the
present invention, the treatment fluids are aqueous gels comprised
of water, a sulfonated or carboxylated gelling agent for gelling
the water and increasing its viscosity, and, optionally, a
crosslinking agent for crosslinking the gelling agent and further
increasing the viscosity of the fluid. The increased viscosity of
the gelled, or gelled and crosslinked, treatment fluid, inter alia,
reduces fluid loss and may allow the treatment fluid to transport
significant quantities of suspended particulates. The water used to
form the treatment fluid may be fresh water, sea water, salt water,
brine, or any other aqueous liquid that does not adversely react
with the other components (such as the gelling agent or
crosslinking agent).
[0015] Any gelling agent that is capable of being sulfonated or
carboxylated may be used in accordance with the present invention,
including hydratable polymers that contain one or more functional
groups such as hydroxyl, carboxyl, sulfate, sulfonate, amino, or
amide groups. The gelling agent may be a hydrated guar split, a
guar flour, a cellulose pulp, or any polysaccharide. Suitable
materials may range from relatively raw materials, such as a guar
splits, to processed materials such as derivatized guar flours.
Particularly useful are polysaccharides that contain one or more of
the monosaccharide units such as galactose, mannose, glucoside,
glucose, xylose, arabinose, fructose, glucuronic acid, or pyranosyl
sulfate. Examples of natural hydratable polymers containing the
foregoing functional groups and units that are suitable for use in
accordance with the present invention include, but are not limited
to, guar, guar derivatives, hydroxypropyl guar, carboxymethyl guar,
xanthan, chitosan, schleroglucan, succinoglycan, starch,
biopolymers, cellulose, cellulose derivatives, and hydroxyethyl
cellulose. Hydratable synthetic polymers and copolymers that
contain the above-mentioned functional groups (e.g., hydroxyl,
carboxyl, sulfate, sulfonate, amino, or amide groups) may also be
used. Examples of such synthetic polymers include, but are not
limited to, acrylamido-methyl-propane sulfonate ("AMPS"),
polyacrylate, polymethacrylate, polyacrylamide, polyvinyl alcohol,
and polyvinylpyrrolidone. With the benefit of this disclosure, it
should be within the ability of one skilled in the art to select an
appropriate gelling agent for use in accordance with the present
invention. Particularly preferred gelling agents include guars,
guar derivatives, and natural polysaccharides.
[0016] As mentioned above, the gelling agents of the present
invention are either sulfonated or carboxylated. This allows the
gelling agents to exhibit unique properties for crosslinking at
higher temperatures and tolerating higher levels of brine in the
subterranean formation. Furthermore, the ring-opening sulfonation
and carboxylation reactions offer higher yields and more consistent
degrees of substitution than previous sulfonation or carboxylation
methods.
[0017] In particular embodiments of the present invention where the
gelling agents are sulfonated, the polysaccharide gelling agents
may be prepared by sulfonating a polysaccharide with a cyclic
sultone or a derivative of a cyclic sultone. Generally, these
reactions involve an entropically-favored, single-step,
ring-opening reaction with a sultone. Suitable sultones include,
but are not limited to, 1,3-propyl sultone, 1,4-butyl sultone, and
derivatives thereof.
[0018] In other embodiments of the present invention, where the
gelling agents are carboxylated, the polysaccharide gelling agents
may be prepared by carboxylating the polysaccharides with a cyclic
lactone or a derivative of a cyclic lactone. Similar to the
sulfonation reactions mentioned above, these reactions typically
involve an entropically-favored, single-step, ring-opening reaction
with a lactone in place of the sultone. Suitable lactones include,
but are not limited to, butyrolactone, .beta.-propiolactone, and
derivatives thereof.
[0019] In other embodiments of the present invention, where the
gelling agents are carboxylated, the polysaccharide gelling agents
may be prepared by carboxylating the polysaccharides with a cyclic
phosphonate acid or a derivative of a cyclic phosphonate acid.
Similar to the sulfonation reactions mentioned above, these
reactions typically involve an entropically-favored, single-step,
ring-opening reaction with a cyclic phosphonate acid or a
derivative of a cyclic phosphonate acid in place of the sultone.
Suitable cyclic phosphonate acids and derivatives include, but are
not limited to, 1,2-oxaphospholane, phosphonate ester, or
derivatives of cyclic phosphonic acids.
[0020] Generally, the sulfonation and carboxylation reactions may
be performed under alkaline conditions, in either an aqueous or a
solid phase. As used herein, references to reaction done in the
"solid phase" refer to reactions with a polymer that has not been
previously dissolved. The polymer may be hydrated to achieve a
solution phase reaction. Once in the presence of alkaline caustic
agents, a sultone or lactone may be added, then heated to achieve a
sulfonation or carboxylation reaction, respectively. Once
sulfonated or carboxylated, the chosen gelling agent is generally
combined with the water to create a treatment fluid. In some
embodiments the sulfonated or carboxylated gelling agent is present
in the treatment fluid in an amount in the range of from about
0.01% to about 3% by weight of the water. In some embodiments the
sulfonated or carboxylated gelling agent is present in the
treatment fluid in an amount in the range of from about 0.01% to
about 2% by weight of the water.
[0021] In particular embodiments, the treatment fluids of the
present invention may also include a crosslinking agent.
Crosslinking agents typically comprise at least one ion that is
capable of crosslinking at least two gelling agent molecules.
Examples of suitable crosslinking agents include, but are not
limited to, N,N'-methylenebisacrylamide, boric acid, disodium
octaborate tetrahydrate, sodium diborate, pentaborates, ulexite and
colemanite, compounds that can supply zirconium IV ions (such as,
for example, zirconium lactate, zirconium lactate triethanolamine,
zirconium carbonate, zirconium acetylacetonate, zirconium malate,
zirconium citrate, and zirconium diisopropylamine lactate);
compounds that can supply titanium IV ions (such as, for example,
titanium lactate, titanium malate, titanium citrate, titanium
ammonium lactate, titanium triethanolamine, and titanium
acetylacetonate); aluminum compounds (such as, for example,
aluminum lactate or aluminum citrate); antimony compounds; chromium
compounds; iron compounds; copper compounds; zinc compounds; or a
combination thereof. An example of a suitable commercially
available zirconium-based crosslinker is "CL-24" available from
Halliburton Energy Services, Inc., Duncan, Okla. An example of a
suitable commercially available titanium-based crosslinking agent
is "CL-39" available from Halliburton Energy Services, Inc., Duncan
Okla. Suitable crosslinking agents generally are present in the
viscosified treatment fluids of the present invention in an amount
sufficient to provide, inter alia, the desired degree of
crosslinking between gelling agent molecules. In some embodiments
of the present invention, the crosslinking agent may be present in
an amount in the range from about 0.001% to about 10% by weight of
the water in the treatment fluid. In some embodiments of the
present invention, the crosslinking agent may be present in an
amount in the range from about 0.01% to about 1% by weight of the
water in the treatment fluid. Individuals skilled in the art, with
the benefit of this disclosure, will recognize the exact type and
amount of crosslinker to use depending on factors such as the
specific gelling agent, desired viscosity, and formation
conditions.
[0022] The gelled or gelled and crosslinked treatment fluids may
also include internal delayed gel breakers such as enzyme,
oxidizing, acid buffer, or temperature-activated gel breakers. The
gel breakers cause the viscous treatment fluids to revert to
relatively thin fluids that can be produced back to the surface
after they have been used to, for example, place particulates in
subterranean fractures. The gel breaker used is typically present
in the servicing fluid in an amount in the range of from about 1%
to about 5% by weight of the gelling agent. The servicing fluids
may also include one or more of a variety of well-known additives,
such as gel stabilizers, fluid loss control additives, clay
stabilizers, bactericides, and the like.
[0023] Generally, the treatment fluids of the present invention are
suitable for use in hydraulic fracturing, frac-packing, and gravel
packing applications. In exemplary embodiments of the present
invention where the treatment fluids are used to carry
particulates, the particulates are generally of a size such that
formation fines that may migrate with produced fluids are prevented
from being produced from the subterranean zone. Any suitable
particulate may be used, including graded sand, bauxite, ceramic
materials, glass materials, walnut hulls, polymer beads, and the
like. Generally, the particulates have a size in the range of from
about 4 to about 400 mesh, U.S. Sieve Series. In some embodiments
of the present invention, the particulates are graded sand having a
particle size in the range of from about 10 to about 70 mesh, U.S.
Sieve Series. In particular embodiments of the present invention,
the particulates may be at least partially coated with a curable
resin, tackifying agents, or some other flowback control agent or
formation fine control agent.
[0024] To facilitate a better understanding of the present
invention, the following examples of preferred embodiments are
given. In no way should the following examples be read to limit or
define the scope of the invention.
EXAMPLES
[0025] FIG. 1 and Table 1 show the results of an experiment wherein
a polysaccharide (guar) was subjected to a ring-opening reaction
under alkaline conditions to sulfonate the polysaccharide.
Initially, a control was prepared by adding 100 g guar bean splits
to 60 g of water at 140.degree. F. followed by 10 g of potassium
chloride and 15 g of sodium hydroxide. Another sample was
identically prepared and then an additional 5 g of 1,3 propane
sultone was added to the second sample. Each sample was dried in a
roller oven for 2 hours at 150.degree. F. in an oxygen-free
environment. After grinding and dehydration, the samples were
sieved and tested for covalent attachment of the sultone.
[0026] To verify the sultone was covalently attached, the powder
was subjected to extraction with dichloromethane using a Soxhlet
apparatus. Evaporation and analysis of the extract demonstrated
that the sultone was not present. Next, characterization by
.sup.13C NMR DEPT spectroscopy unambiguously identified attachment
of the sultone onto the powder. The DEPT experiment distinguishes
between methyl (CH3), methylene (CH2) and methine (CH) carbons by
showing the opposite phase signal for the methylene as opposed to
the methyl and methine carbons. Successful attachment of the
sultone is demonstrated unambiguously by the identification of
three new methylene peaks shown in FIG. 1. The common methylene
signal as expected is from the native and derivatized guar. The
methylene peaks demonstrate the attachment of a sultone functional
group to the guar.
[0027] To further characterize the differences between the
derivatized and underivatized guar powders, a hydration test was
run by measuring the change in viscosity with time. A concentration
of 40 pounds per thousand gallons concentration was prepared for
each gelling agent in tap water containing 2% (wt/wt) KCl. The
change in viscosity with time was measured using a Fann 35
viscometer and the results are presented in Table 1. The difference
in base gel viscosities from otherwise identical samples
demonstrates the change in physical property from the
derivitization of the polymer. TABLE-US-00001 TABLE 1 visc cP time
visc cP derivatized with (min) control 1,3-propane sultone 2 14 13
3 16.8 17 4 18.7 19.9 5 20.2 22.3 10 24 27.7 20 25.4 30.25 30 25.6
30.8 60 25.9 32 120 25.9 32.5
[0028] Therefore, the present invention is well adapted to attain
the ends and advantages mentioned as well as those that are
inherent therein. While numerous changes may be made by those
skilled in the art, such changes are encompassed within the spirit
of this invention as defined by the appended claims.
* * * * *