U.S. patent application number 11/210519 was filed with the patent office on 2005-12-22 for methods of consolidating subterranean zones and compositions therefor.
This patent application is currently assigned to Halliburton Energy Services, Inc.. Invention is credited to Barton, Johnny A., Nguyen, Philip D..
Application Number | 20050282973 11/210519 |
Document ID | / |
Family ID | 33564690 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050282973 |
Kind Code |
A1 |
Nguyen, Philip D. ; et
al. |
December 22, 2005 |
Methods of consolidating subterranean zones and compositions
therefor
Abstract
Methods of consolidating subterranean zones and hardenable resin
compositions are provided. A hardenable resin composition of the
invention basically comprises a furan liquid resin mixture
comprising a 2-furanmethanol homopolymer and furfuryl alcohol, an
organosilane coupling agent and an acid catalyst.
Inventors: |
Nguyen, Philip D.; (Duncan,
OK) ; Barton, Johnny A.; (Marlow, OK) |
Correspondence
Address: |
Robert A. Kent
2600 S. 2nd Street
Duncan
OK
73536-0440
US
|
Assignee: |
Halliburton Energy Services,
Inc.
|
Family ID: |
33564690 |
Appl. No.: |
11/210519 |
Filed: |
August 24, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11210519 |
Aug 24, 2005 |
|
|
|
10616052 |
Jul 9, 2003 |
|
|
|
Current U.S.
Class: |
525/410 |
Current CPC
Class: |
C09K 8/5083 20130101;
C09K 8/512 20130101; C09K 8/5753 20130101; C09K 8/5756
20130101 |
Class at
Publication: |
525/410 |
International
Class: |
C08G 065/32 |
Claims
What is claimed is:
1. A hardenable resin composition comprising: a furan liquid resin
mixture comprising a 2-furanmethonal homopolymer and furfuryl
alcohol; an organosilane coupling agent; and an acid catalyst.
2. The composition of claim 1 wherein said 2-furanmethonal
homopolymer is present in said furan liquid resin mixture in an
amount in the range of from about 55% to about 60% by weight
thereof and said furfuryl alcohol is present in said mixture in an
amount in the range of from about 40% to about 45% by weight
thereof.
3. The composition of claim 1 wherein said furan liquid resin
mixture is present in said hardenable resin composition in an
amount in the range of from about 20% to about 60% by weight
thereof.
4. The composition of claim 1 wherein said solvent is selected from
the group consisting of furfuryl acetate, C.sub.1-C.sub.8 alkyl
acetates, 2-butoxy ethanol, diethylene glycol methyl ether,
diethylene glycol dimethyl ether, and dipropylene glycol methyl
ether.
5. The composition of claim 1 wherein said solvent is furfuryl
acetate.
6. The composition of claim 1 wherein said solvent is present in
said hardenable resin composition in an amount in the range of from
about 40% to about 80% by weight thereof.
7. The composition of claim 1 wherein said organosilane coupling
agent is selected from the group consisting of
N-2-(aminoethyl)-3-aminopropyltrime- thoxysilane,
3-glycidoxypropyltrimethoxysilane and n-beta-(aminoethyl)-gam-
ma-aminopropyltrimethoxysilane.
8. The composition of claim 1 wherein said organosilane coupling
agent is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.
9. The composition of claim 1 wherein said organosilane coupling
agent is present in said hardenable resin composition in an amount
in the range of from about 0.1% to about 2% by weight thereof.
10. The composition of claim 1 wherein said acid catalyst is
selected from the group consisting of salicylic acid,
ethylenediaminetriacetic acid, benzoic acid, oxalic acid, maleic
acid, alkyl benzenesulfonic acid and salts thereof.
11. The composition of claim 1 wherein said acid catalyst is an
alkyl benzenesulfonic acid.
12. The composition of claim 1 wherein said acid catalyst is
present in said hardenable resin composition in an amount in the
range of from about 0.01% to about 10% by weight thereof.
Description
[0001] This application is a divisional of application Ser. No.
10/616,052 filed on Jul. 9, 2003
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention provides methods of consolidating
subterranean zones and hardenable resin compositions therefor.
[0004] 2. Description of the Prior Art
[0005] Hydrocarbon producing wells are often completed in
unconsolidated formations containing loose and incompetent
particulate solids which migrate with hydrocarbons or hydrocarbons
and water produced by the wells. The presence of the particulate
solids in the produced fluids is highly undesirable in that the
solid particles abrade tublar goods, pumping equipment, valves and
other producing equipment and reduce the fluid production
capabilities of the producing zones in the wells. Incompetent
subterranean formations include those which contain loose
particulate solids that are readily entrained by produced fluids
and those wherein the particulate solids making up the formations
are bonded together with insufficient strength to withstand the
forces produced by the production of fluids from the formations. A
technique which is often used for minimizing particulate solid
production from unconsolidated formations has been to produce
fluids from the formations at low flow rates whereby the near well
stabilities of particulate solid bridges and the like in the
formations are preserved. However, the collapse of such particulate
solid bridges often occurs as a result of unintentional high
production rates and/or pressure cycling. Pressure cycling occurs
from frequent shut-ins and start-ups of a well. The frequency of
the pressure cycling is very critical to the longevity of the near
well formation, especially during the depletion stage of the well
when the pore pressure of the formation has already been
significantly reduced.
[0006] Heretofore, unconsolidated formations have been treated by
injecting hardenable resin compositions into the formation and then
allowing the resin compositions to harden whereby the
unconsolidated formations are consolidated. While such heretofore
utilized consolidating techniques have been used successfully, in
high temperature subterranean zones, i.e., subterranean zones
having temperatures above about 200.degree. F., the hardenable
resins have been broken down by chemical attack and/or thermal
degradation thereby again allowing particulate solids to migrate
with produced fluids. Also, to ensure that particulate solids are
not produced, costly gravel packs, sand screens and the like have
been installed in subterranean producing formations. However,
because gravel packs and sand screens filter out particulate solids
from the produced fluids, the presence of the filtered particulate
solids adds to the flow resistance thereby producing additional
pressure draw down which causes portions of the unconsolidated
formations to break down.
[0007] Thus, there are needs for improved methods and hardenable
resin compositions for consolidating unconsolidated subterranean
zones whereby particulate solids do not migrate with produced
fluids.
SUMMARY OF THE INVENTION
[0008] The present invention provides improved methods and
compositions for consolidating subterranean zones including those
having high temperatures which meet the needs described above and
overcome the deficiencies of the prior art.
[0009] A method of this invention for consolidating a subterranean
zone comprises the following steps. A brine preflush containing a
cationic surfactant is introduced into the subterranean zone around
and adjacent to the well bore penetrating it. A hardenable resin
composition is next introduced into the subterranean zone around
and adjacent to the well bore. The hardenable resin composition
comprises a furan liquid resin mixture, a solvent, an organosilane
coupling agent and an acid catalyst. Thereafter, a brine overflush
containing a cationic surfactant is introduced into the
subterranean zone to displace the resin composition from the pore
space in the subterranean zone, and the hardenable resin
composition is allowed to harden whereby the subterranean zone
around and adjacent to the well bore is consolidated into a
permeable mass.
[0010] Another method of consolidating a subterranean zone includes
the following steps. A brine preflush containing a cationic
surfactant is introduced into the subterranean zone around and
adjacent to the well bore penetrating the zone. A hardenable resin
composition is next introduced into the subterranean zone around
and adjacent to the well bore. The hardenable resin composition
comprises a furan liquid resin mixture, a solvent, an organosilane
coupling agent and an acid catalyst. A clean-up brine is next
circulated in the well bore penetrating the subterranean zone to
remove the hardenable resin composition from the well bore without
significantly disturbing the hardenable resin composition in the
subterranean zone. The hardenable resin composition is then allowed
to harden whereby the subterranean zone around and adjacent to the
well bore including in the pore spaces thereof is consolidated into
a solid impermeable mass. Thereafter, the subterranean zone is
fractured and particulate proppant material is placed in the
fractures to provide flow channels through the solid impermeable
mass.
[0011] The hardenable resin composition of this invention basically
comprises a furan liquid resin mixture comprising a 2-furanmethanol
homopolymer and furfuryl alcohol, a solvent, an organosilane
coupling agent and an acid catalyst.
[0012] The objects, features and advantages of the present
invention will be readily apparent to those skilled in the art upon
a reading of the description of preferred embodiments which
follows.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The present invention provides methods of consolidating
unconsolidated subterranean zones penetrated by well bores and
hardenable resin compositions that are useful therefor. A method of
the invention for consolidating a subterranean zone penetrated by a
well bore comprises the following steps. A brine preflush
containing a cationic surfactant is introduced into the
subterranean zone around and adjacent to the well bore to remove
debris and fines from the pore spaces in the subterranean zone. A
hardenable resin composition is next introduced into the
subterranean zone around and adjacent to the well bore. The
hardenable resin composition comprises a furan liquid resin
mixture, a solvent, an organosilane coupling agent and an acid
catalyst. Thereafter, a brine overflush containing a cationic
surfactant is introduced into the subterranean zone to displace the
resin composition from the pore spaces in the subterranean zone,
and the hardenable resin composition is allowed to harden whereby
the subterranean zone around and adjacent to the well bore is
consolidated into a permeable mass.
[0014] The brine preflush and overflush utilized in accordance with
this invention are preferably sodium chloride brines. The sodium
chloride is generally present in the brines in an amount of about
15% by weight of the brines.
[0015] The cationic surfactant included in the brine preflush and
overflush is selected from the group consisting of ethoxylated
nonyl phenol phosphate ester, C.sub.12 to C.sub.22 alkyl
phosphonate surfactants and mixtures of one or more cationic
surfactants and one or more non-ionic surfactants. Of these, a
C.sub.12-C.sub.22 alkyl phosphonate surfactant is preferred. The
cationic surfactant in the brine preflush functions to improve the
contact of the hardenable resin composition with surfaces in the
subterranean zone. The cationic surfactant in the overflush
functions to water-wet the surfaces in the pore spaces. The
cationic surfactant utilized is present in the brine preflush and
overflush in an amount in the range of from about 0.01% to about 3%
by weight of the preflush and overflush.
[0016] The furan liquid resin mixture in the hardenable resin
composition comprises a 2-furanmethanol homopolymer present in the
mixture in an amount in the range of from about 55% to about 60% by
weight thereof and furfuryl alcohol present in the mixture in an
amount in the range of from about 40% to about 45% by weight
thereof. The furan liquid mixture is present in the hardenable
resin composition in an amount in the range of from about 20% to
about 60% by weight thereof.
[0017] The solvents that can be utilized in the hardenable resin
composition include, but are not limited to, hydrolyzable alkyl
esters, glycol ethers and mixtures thereof. Examples of
hydrolyzable esters are furfuryl acetate and C.sub.1 to C.sub.8
alkyl acetates such as butyl acetate. Examples of glycol ethers are
2-butoxy ethanol, diethylene glycol methyl ether, dithylene glycol
dimethyl ether and dipropylene glycol methyl ether. Of these,
furfuryl acetate is preferred. The solvent utilized is present in
the hardenable resin composition in an amount in the range of from
about 40% to about 80% by weight of the hardenable resin
composition.
[0018] Examples of organosilane coupling agents that can be
utilized in the hardenable resin composition include, but are not
limited to, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane,
3-glycidoxypropyltrimetho- xysilane and
n-beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane. Of these,
N-2-(aminoethyl)-3-aminopropyltrimethoxysilane is preferred. The
organosilane coupling agent utilized is present in the hardenable
resin composition in an amount in the range of from about 0.1% to
about 2% by weight thereof.
[0019] The furan liquid resin mixture solvent and organosilane
coupling agent of the hardenable resin composition can be
preblended as a single component that has a long shelf life ranging
from several months to a few years and that can be transported to
the well site ready for use without additional preparation. The
acid catalyst utilized is mixed with the furan liquid resin mixture
and organosilane coupling agent component just prior to introducing
the hardenable resin composition into the subterranean zone to be
consolidated. Preferably, the acid catalyst is metered into the
furan liquid resin and organosilane coupling agent mixture as the
mixture is pumped into the well bore and the subterranean zone.
[0020] The acid catalyst utilized in the hardenable resin
composition is preferably an oil soluble acid or a slightly water
soluble acid. Examples of such acids include, but are not limited
to, salicylic acid, ethylenediaminetriacetic acid, benzoic acid,
oxalic acid, maleic acid, alkyl benzenesulfonic acids such as
toluene sulfonic acid, dodecyl benzene sulfonic acid, and the salts
of such acids. Of these, alkyl benzenesulfonic acid is preferred.
The acid catalyst is included in the hardenable resin composition
in an amount in the range of from about 0.01% to about 10% by
weight thereof, preferably in an amount of about 4%.
[0021] The brine preflush described above is preferably introduced
into the subterranean zone to be consolidated at a pressure below
the fracture pressure of the zone and at a rate in the range of
from about 0.1 to about 5 barrels per minute. A total volume of the
brine preflush introduced into the subterranean zone is preferably
at least about 20 gallons of the brine preflush per foot of the
well bore interval in the subterranean zone being consolidated.
[0022] The brine overflush introduced into the subterranean zone
after the hardenable resin composition has been introduced therein
is at a pressure below the fracture pressure of the zone and a rate
in the range of from about 0.1 to about 5 barrels per minute. The
total volume of the brine overflush introduced into the
subterranean zone is preferably a volume of about three times the
volume of the brine preflush that was introduced into the zone.
[0023] As mentioned above, after the brine overflush has been
introduced into the subterranean zone to remove hardenable resin
composition from the pore spaces in the zone, the hardenable resin
composition is allowed to harden whereby the subterranean zone
around and adjacent to the well bore is formed into a consolidated
permeable mass. The consolidated permeable mass around and adjacent
to the well bore prevent loose and incompetent sands and fines from
flowing into the well bore with produced fluids.
[0024] An alternate method of this invention for consolidating a
subterranean zone penetrated by a well bore that can be utilized is
comprised of the following steps. A brine preflush containing a
cationic surfactant is introduced into the subterranean zone around
and adjacent to the well bore. A hardenable resin composition is
next introduced into the subterranean zone around and adjacent to
the well bore. The hardenable resin composition is comprised of a
furan liquid resin mixture, a solvent, an organosilane coupling
agent and an acid catalyst. A clean-up brine is next circulated in
the well bore penetrating the subterranean zone to remove
hardenable resin composition therefrom without significantly
disturbing the hardenable resin composition in the subterranean
zone. The hardenable resin composition is then allowed to harden in
the subterranean zone around and adjacent to the well bore
including in the pore spaces thereof whereby the subterranean zone
is consolidated into a solid impermeable mass. Thereafter, the
subterranean zone is perforated and fractured and particulate
proppant material is placed in the fractures to provide flow
channels through the solid impermeable mass that prevent
unconsolidated sands and fines from being carried into the well
bore with produced fluids.
[0025] The procedures utilized in fracturing subterranean zones and
placing particulate proppant material in the fractures to thereby
form fluid conductive channels therein are well known to those
skilled in the art. The particulate proppant material utilized can
be coated with a hardenable resin composition whereby after being
placed in the fractures, the particulate proppant material is
formed into hard permeable packs which prevent unconsolidated sands
and fines from flowing through the fractures with produced
fluids.
[0026] The brine preflush and clean-up solutions utilized in
accordance with the alternate method are formed of the same
components in the same amounts as those in the first method
described above. Also, the components and amounts of components in
the hardenable resin composition are the same as those described
above.
[0027] A preferred method of this invention for consolidating a
subterranean zone penetrated by a well bore comprises the steps of:
(a) introducing a brine preflush containing a cationic surfactant
into the subterranean zone around and adjacent to the well bore;
(b) introducing a hardenable resin composition into the
subterranean zone around and adjacent to the well bore, the
hardenable resin composition comprising a furan liquid resin
mixture, a solvent, an organosilane coupling agent and an acid
catalyst; (c) introducing a brine overflush containing a cationic
surfactant into the subterranean zone to displace the resin
composition from the pore spaces in the subterranean zone; and (d)
allowing the hardenable resin composition to harden and form the
subterranean zone around and adjacent to the well bore into a
consolidated permeable mass.
[0028] Another method of the present invention for consolidating a
subterranean zone penetrated by a well bore comprises the steps of:
(a) introducing a brine preflush containing a cationic surfactant
into the subterranean zone around and adjacent to the well bore;
(b) introducing a hardenable resin composition into the
subterranean zone around and adjacent to the well bore, the
hardenable resin composition comprising a furan liquid resin
mixture, an organosilane coupling agent and an acid catalyst; (c)
circulating a clean-up brine in the well bore penetrating the
subterranean zone to remove hardenable resin composition therefrom
without significantly disturbing the hardenable resin composition
in the subterranean zone; (d) allowing the hardenable resin
composition to harden in the subterranean zone whereby the
subterranean zone around and adjacent to the well bore including in
the pore spaces thereof is consolidated into a solid impermeable
mass; and then (e) fracturing the subterranean zone and placing
particulate proppant material therein to provide flow channels
through the solid impermeable mass.
[0029] A hardenable resin composition of this invention comprises:
a furan liquid resin mixture comprising a 2-furanmethanol
homopolymer and furfuryl alcohol; a solvent; an organosilane
coupling agent; and an acid catalyst.
[0030] In order to further illustrate the methods of this
invention, the following examples are given.
EXAMPLE 1
[0031] Inside a brass cylinder flow cell which had an inside
diameter of 1.38 inches, 185 grams of 70/170 mesh-sand were packed
to a length of 4.63 inches. A 200 mL brine solution of 15% sodium
chloride which contained an alkyl phosphonate cationic surfactant
in a concentration of 0.25% by weight of the brine solution was
pre-flushed through the sand pack under vacuum. Next, 35 mL of a
resin mixture containing 40% of a furan liquid resin mixture, 48%
of furfuryl acetate, 1% of
N-2-(aminoethyl)-3-amino-propyltrimethoxy silane and 1% of an alkyl
phosphonate cationic surfactant were flushed through the sand pack
in a similar manner to that of the preflush. The packed sand was
then overflushed with 200 mL of 15% sodium chloride brine
containing an alkyl phosphonate cationic surfactant in a
concentration of 0.25% by weight of the brine solution. The sand
pack was allowed to be saturated with brine solution and the
cylinder was then placed in an oven at 325.degree. F. for a 20-hour
cure without applying closure stress. After curing, the sand pack
was removed from the cylinder and cores were tested for unconfined
compressive strength. An average unconfined compressive strength of
4,745 psi was obtained.
EXAMPLE 2
[0032] Inside the brass cylinder flow cell described above, 185
grams of 40/60-mesh Ottawa sand was packed to a length of 4.75
inches. A 150 mL brine solution of 15% sodium chloride which
contained an alkyl phosphonate cationic surfactant at a
concentration of 0.25% by weight of the brine solution was
pre-flushed through the sand pack under vacuum. Next, 100 mL of a
resin mixture containing 40% of a furan liquid resin mixture, 48%
of furfuryl acetate, 1% of N-2-(aminoethyl)-3-aminopropyltri-
methoxy silane and 1% of an alkyl phosphonate cationic surfactant
was flushed through the sand pack in a similar manner as that of
the preflush. The packed sand was then overflushed with 250 mL of
15% sodium chloride brine containing an alkyl phosphonate cationic
surfactant in a concentration of 0.25% by weight of the brine
solution. The sand pack was allowed to be saturated with brine
solution and the cylinder was then placed in an oven at 325.degree.
F. for a 22-hour cure without applying closure stress. After
curing, the sand pack was removed from the cylinder and cores were
tested to measure unconfined compressive strengths. The average
unconfined compressive strength was 4,630 psi.
[0033] Thus, the present invention is well adapted to attain the
objects and advantages mentioned as well as those which 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.
* * * * *