U.S. patent application number 10/945487 was filed with the patent office on 2005-02-17 for cement compositions with improved fluid loss characteristics and methods of cementing in surface and subterranean applications.
Invention is credited to Caveny, William J., Koch, Ronney R., Morgan, Rickey L..
Application Number | 20050034864 10/945487 |
Document ID | / |
Family ID | 35423329 |
Filed Date | 2005-02-17 |
United States Patent
Application |
20050034864 |
Kind Code |
A1 |
Caveny, William J. ; et
al. |
February 17, 2005 |
Cement compositions with improved fluid loss characteristics and
methods of cementing in surface and subterranean applications
Abstract
An improved fluid loss control additive and methods of using
such compositions in surface and subterranean applications are
provided. A method of cementing in a subterranean formation, that
comprises providing a cement composition that comprises a cement,
water, and a fluid loss control additive, the fluid loss control
additive comprising an acrylic acid copolymer derivative, an iron
compound, and at least one of a hydratable polymer or a dispersant,
placing the cement composition into the subterranean formation, and
permitting the cement composition to set therein, is provided. Also
provided are methods of reducing the fluid loss from a cement
composition, cement compositions, and fluid loss control
additives.
Inventors: |
Caveny, William J.; (Rush
Springs, OK) ; Morgan, Rickey L.; (Duncan, OK)
; Koch, Ronney R.; (Duncan, OK) |
Correspondence
Address: |
CRAIG W. RODDY
HALLIBURTON ENERGY SERVICES
P.O. BOX 1431
DUNCAN
OK
73536-0440
US
|
Family ID: |
35423329 |
Appl. No.: |
10/945487 |
Filed: |
September 20, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10945487 |
Sep 20, 2004 |
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10891384 |
Jul 14, 2004 |
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10891384 |
Jul 14, 2004 |
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10608748 |
Jun 27, 2003 |
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Current U.S.
Class: |
166/293 |
Current CPC
Class: |
C04B 28/02 20130101;
C04B 28/02 20130101; C04B 40/0039 20130101; C04B 40/0039 20130101;
C04B 14/047 20130101; C04B 14/047 20130101; C04B 2103/0014
20130101; C04B 24/2652 20130101; C04B 14/047 20130101; C04B 24/20
20130101; C04B 24/163 20130101; C04B 24/163 20130101; C04B 22/12
20130101; C04B 24/163 20130101; C04B 2103/408 20130101; C04B 24/383
20130101; C04B 14/047 20130101; C04B 2103/408 20130101; C04B 14/047
20130101; C04B 14/108 20130101; C04B 14/062 20130101; C04B 14/062
20130101; C04B 14/108 20130101; C04B 2103/0014 20130101; C04B 24/18
20130101; C04B 14/062 20130101; C04B 14/108 20130101; C04B 24/2641
20130101; C04B 22/124 20130101; C04B 24/163 20130101; C04B 2103/408
20130101; C04B 14/062 20130101; C04B 24/383 20130101; C04B
2103/0014 20130101; C04B 24/22 20130101; C04B 14/062 20130101; C04B
24/163 20130101; C04B 14/108 20130101; C04B 14/108 20130101; C04B
24/04 20130101; C04B 2103/408 20130101; C04B 24/383 20130101; C04B
24/06 20130101; C09K 8/487 20130101; C04B 40/0039 20130101; C04B
40/0039 20130101; C04B 28/02 20130101; C04B 28/02 20130101; C04B
2103/46 20130101; C04B 28/02 20130101 |
Class at
Publication: |
166/293 |
International
Class: |
E21B 033/13 |
Claims
What is claimed is:
1. A method of cementing in a subterranean formation comprising:
providing a cement composition comprising a cement, water, and a
fluid loss control additive, the fluid loss control additive
comprising: an acrylic acid copolymer derivative, an iron compound,
and at least one of a hydratable polymer or a dispersant; placing
the cement composition into the subterranean formation; and
permitting the cement composition to set therein.
2. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a copolymer or a copolymer salt that comprises
first monomers formed from N,N-dimethylacrylamide, and second
monomers formed from 2-acrylamido-2-methylpropane sulfonic acid or
a derivative thereof.
3. The method of claim 2 wherein the copolymer or the copolymer
salt has a N,N-dimethylacrylamide to 2-acrylamido-2-methylpropane
sulfonic acid or a derivative thereof mole ratio of from about 1:4
to about 4:1.
4. The method of claim 2 wherein the copolymer or the copolymer
salt has a weight average molecular weight of between about 75,000
daltons and about 300,000 daltons.
5. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a graft polymer comprising a backbone
comprising at least one of a lignin, a lignite, or their salts and
a grafted pendant group comprising monomers formed from at least
one of 2-acrylamido-2-methylprop- ane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
6. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a graft polymer comprising a backbone
comprising at least one of derivatized cellulose, polyvinyl
alcohol, polyethylene oxide, or polypropylene oxide, and a grafted
pendant group comprising monomers formed from at least one of
2-acrylamido-2-methylpropane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
7. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a copolymer or a copolymer salt comprising
first monomers formed from 2-acrylamido-2-methylpropane sulfonic
acid or a derivative thereof.
8. The method of claim 7 wherein the copolymer or the copolymer
salt comprises first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof,
second monomers formed from maleic acid or a salt thereof, third
monomers formed from N-vinyl caprolactam, and fourth monomers
formed from 4-hydroxybutyl vinyl ether.
9. The method of claim 7 wherein the copolymer or the copolymer
salt comprises a copolymer comprising first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof,
and second monomers formed from hydrolyzed acrylamide.
10. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a copolymer or copolymer salt comprising a
waffle tannin having monomers formed from at least one of
2-acrylamido-2-methylpropane sulfonic acid or acrylamide grafted
thereto.
11. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises 1 part by weight of a polymer comprising 70
mole % of AMPS, 17 mole % of N, N-dimethylacrylamide, and 13 mole %
of acrylamide, and 2 parts by weight of hydroxyethylcellulose
having 1.5 moles of ethylene oxide substitution.
12. The method of claim 1 wherein the acrylic acid copolymer
derivative comprises a copolymer or copolymer salt of a vinylamide
morpholine derivative and least one branched N-vinylamide
derivative, wherein the vinylamide morpholine derivative is
selected from compounds represented by the formula: 4wherein
R.sub.1--H or --CH.sub.3 and R.sub.2 is --H, --CH.sub.3, or
--CH.sub.2CH.sub.3 and is positioned on any of the four carbon
atoms in the morpholine ring, and the N-vinylamide derivative is
selected from the compounds represented by the formula: 5wherein
R.sub.3 is R.sub.1--H or --CH.sub.3; R.sub.4 is --H, --CH.sub.3,
--CH.sub.2CH.sub.3, --CH(CH.sub.3).sub.2, --C(CH.sub.3).sub.3, or
--CH(CH.sub.3).sub.2SO.sub.3X, wherein X is --Na, --NH.sub.4, or
--Ca1/2, and R.sub.5 is --H, --CH.sub.3, or --CH.sub.2CH.sub.3.
13. The method of claim 12 wherein the vinylamide derivative is
acryloylmorpholine, and the branched N-vinylamide derivative is a
sodium salt of 2-acrylamido-2-methylpropanesulfonic acid.
14. The method of claim 12 wherein the vinylamide derivative is
acryloylmorpholine, a first vinylamide derivative is a sodium salt
of 2-acrylamido-2-methylpropanesulfonic acid, and a second
vinylamide derivative is acrylamide.
15. The method of claim 1 wherein the hydratable polymer comprises
carboxymethylcellulose, hydroxyethylcellulose,
carboxymethylhydroxyethylc- ellulose, a vinyl sulfonated polymer, a
hydratable graft polymer, or a mixture thereof.
16. The method of claim 1 wherein the hydratable polymer is present
in the fluid loss control additive in an amount in the range of
from about 0.1% to about 15% by weight of the fluid loss control
additive.
17. The method of claim 1 wherein the dispersant comprises a sodium
salt of napthalene sulfonic acid, or a water-soluble polymer
prepared by the caustic-catalyzed condensation of formaldehyde with
acetone wherein the polymer contains sodium sulfate groups.
18. The method of claim 1 wherein the dispersant is present in the
fluid loss control additive in an amount sufficient to prevent
gelation of the cement composition.
19. The method of claim 1 wherein the dispersant is present in the
fluid loss control additive in an amount in the range of from about
5% to about 70% by weight of the fluid loss control additive.
20. The method of claim 1 wherein the iron compound is present in
the fluid loss control additive in an amount in the range of from
about 5% to about 25% by weight of the fluid loss control
additive.
21. The method of claim 1 wherein the iron compound is present in
the fluid loss control additive in an amount in the range of from
about 10% to about 15% by weight of the fluid loss control
additive.
22. The method of claim 1 wherein the iron compound is an iron
chloride or an iron gluconate.
23. The method of claim 22 wherein the iron chloride is ferrous
chloride, ferric chloride, or a mixture thereof.
24. The method of claim 1 wherein the fluid loss control additive
further comprises a zeolite.
25. The method of claim 24 wherein the zeolite further comprises
chabazite and amorphous silica.
26. The method of claim 24 wherein the zeolite is present in the
fluid loss control additive in an amount in the range of from about
0.1% to about 15% by weight of the fluid loss control additive.
27. The method of claim 24 wherein the fluid loss control additive
further comprises an organic acid, a deaggregation agent, silica,
or a combination thereof.
28. The method of claim 1 wherein the fluid loss control additive
further comprises a shale.
29. The method of claim 28 wherein the shale comprises vitrified
shale.
30. The method of claim 28 wherein the shale is present in the
fluid loss control additive in an amount in the range of from about
0.1% to about 15% by weight of the fluid loss control additive.
31. The method of claim 28 wherein the fluid loss control additive
further comprises an organic acid, a deaggregation agent, silica,
or a combination thereof.
32. The method of claim 31 wherein the organic acid is present in
the fluid loss control additive in an amount sufficient to provide
a desired degree of viscosity control.
33. The method of claim 31 wherein the organic acid is present in
the fluid loss control additive in an amount in the range of from
about 0.01% to about 5% by weight of the fluid loss control
additive.
34. The method of claim 31 wherein the deaggregation agent is
present in the fluid loss control additive in an amount sufficient
to enable the fluid loss control additive to flow freely as a
powder.
35. The method of claim 31 wherein the deaggregation agent is
present in the fluid loss control additive in an amount in the
range of from about 1% to about 15% by weight of the fluid loss
control additive.
36. The method of claim 31 wherein the silica is high surface area
amorphous silica.
37. The method of claim 36 wherein the high surface area amorphous
silica is present in the fluid loss control additive in an amount
sufficient to provide a desired after-set compressive strength.
38. The method of claim 36 wherein the high surface area amorphous
silica is present in the fluid loss control additive in an amount
in the range of from about 0.1% to about 15% by weight of the fluid
loss control additive.
39. The method of claim 1 wherein the cement comprises a Portland
cement, a pozzolanic cement, a gypsum cement, a high alumina
content cement, a silica cement, or a high alkalinity cement.
40. The method of claim 1 wherein the water is present in the
cement composition in an amount sufficient to form a pumpable
slurry.
41. The method of claim 1 wherein the water is present in the
cement composition in an amount in the range of from about 15% to
about 200% by weight of cement.
42. The method of claim 1 wherein the cement composition has a
density in the range of from about 5 pounds per gallon to about 30
pounds per gallon.
43. The method of claim 1 wherein the fluid loss control additive
is present in the cement composition in an amount sufficient to
provide a desired degree of fluid loss control.
44. The method of claim 1 wherein the fluid loss control additive
is present in the cement composition in an amount in the range of
from about 0.01% to about 5% by weight of cement.
45. The method of claim 1 wherein the acrylic acid copolymer
derivative is present in the fluid loss control additive in an
amount in the range of from about 1% to about 99% by weight.
46. The method of claim 1 wherein the fluid loss control additive
is present in the cement composition in an amount in the range of
from about 0.01% to about 5% by weight of cement, the iron compound
is present in the fluid loss control additive in an amount in the
range of from about 10% to about 15% by weight of the fluid loss
control additive, the hydratable polymer is present in the fluid
loss control additive in an amount in the range of from about 1% to
about 5% by weight of the fluid loss control additive, and the
dispersant is present in the fluid loss control additive in an
amount in the range of from about 20% to about 45% by weight of the
fluid loss control additive.
47. A method of reducing the fluid loss from a cement composition,
comprising adding to the cement composition a fluid loss control
additive comprising: an acrylic acid copolymer derivative, an iron
compound, and at least one of a dispersant or a hydratable
polymer.
48. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a copolymer or a copolymer salt that comprises
first monomers formed from N,N-dimethylacrylamide, and second
monomers formed from 2-acrylamido-2-methylpropane sulfonic acid or
a derivative thereof.
49. The method of claim 48 wherein the copolymer or the copolymer
salt has a N,N-dimethylacrylamide to 2-acrylamido-2-methylpropane
sulfonic acid or a derivative thereof mole ratio of from about 1:4
to about 4:1.
50. The method of claim 48 wherein the copolymer or the copolymer
salt has a weight average molecular weight of between about 75,000
daltons and about 300,000 daltons.
51. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a graft polymer comprising a backbone
comprising at least one of a lignin, a lignite, or their salts and
a grafted pendant group comprising monomers formed from at least
one of 2-acrylamido-2-methylprop- ane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
52. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a graft polymer comprising a backbone
comprising at least one of derivatized cellulose, polyvinyl
alcohol, polyethylene oxide, or polypropylene oxide, and a grafted
pendant group comprising monomers formed from at least one of
2-acrylamido-2-methylpropane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
53. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a copolymer or a copolymer salt comprising
first monomers formed from 2-acrylamido-2-methylpropane sulfonic
acid or a derivative thereof.
54. The method of claim 53 wherein the copolymer or the copolymer
salt comprises first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof,
second monomers formed from maleic acid or a salt thereof, third
monomers formed from N-vinyl caprolactam, and fourth monomers
formed from 4-hydroxybutyl vinyl ether.
55. The method of claim 53 wherein the copolymer or the copolymer
salt comprises a copolymer comprising first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof,
and second monomers formed from hydrolyzed acrylamide.
56. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a copolymer or copolymer salt comprising a
waffle tannin having monomers formed from at least one of
2-acrylamido-2-methylpropane sulfonic acid or acrylamide grafted
thereto.
57. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises 1 part by weight of a polymer comprising 70
mole % of AMPS, 17 mole % of N, N-dimethylacrylamide, and 13 mole %
of acrylamide, and 2 parts by weight of hydroxyethylcellulose
having 1.5 moles of ethylene oxide substitution.
58. The method of claim 47 wherein the acrylic acid copolymer
derivative comprises a copolymer or copolymer salt of a vinylamide
morpholine derivative and least one branched N-vinylamide
derivative, wherein the vinylamide morpholine derivative is
selected from compounds represented by the formula: 6wherein
R.sub.1--H or --CH.sub.3 and R.sub.2 is --H, --CH.sub.3, or
--CH.sub.2CH.sub.3 and is positioned on any of the four carbon
atoms in the morpholine ring, and the N-vinylamide derivative is
selected from the compounds represented by the formula: 7wherein
R.sub.3 is R.sub.1--H or --CH.sub.3; R.sub.4 is --H, --CH.sub.3,
--CH.sub.2CH.sub.3, --CH(CH.sub.3).sub.2, --C(CH.sub.3).sub.3, or
--CH(CH.sub.3).sub.2SO.sub.3X, wherein X is --Na, --NH.sub.4, or
--Ca1/2, and R.sub.5 is --H, --CH.sub.3, or --CH.sub.2CH.sub.3.
59. The method of claim 58 wherein the vinylamide derivative is
acryloylmorpholine and the branched N-vinylamide derivative is a
sodium salt of b 2-acrylamido-2-methylpropanesulfonic acid.
60. The method of claim 58 wherein the vinylamide derivative is
acryloylmorpholine, a first vinylamide derivative is a sodium salt
of 2-acrylamido-2-methylpropanesulfonic acid, and a second
vinylamide derivative is acrylamide.
61. The method of claim 47 wherein the hydratable polymer comprises
carboxymethylcellulose, hydroxyethylcellulose,
carboxymethylhydroxyethylc- ellulose, a vinyl sulfonated polymer, a
hydratable graft polymer, or a mixture thereof.
62. The method of claim 47 wherein the dispersant comprises a
sodium salt of napthalene sulfonic acid, or a water-soluble polymer
prepared by the caustic-catalyzed condensation of formaldehyde with
acetone wherein the polymer contains sodium sulfate groups.
63. The method of claim 47 wherein the dispersant is present in the
fluid loss control additive in an amount sufficient to prevent
gelation of the cement composition.
64. The method of claim 47 wherein the iron compound is an iron
chloride or an iron gluconate.
65. The method of claim 64 wherein the iron chloride is ferrous
chloride, ferric chloride, or a mixture thereof.
66. The method of claim 47 wherein the fluid loss control additive
further comprises a zeolite.
67. The method of claim 66 wherein the zeolite further comprises
chabazite and amorphous silica.
68. The method of claim 66 wherein the zeolite is present in the
fluid loss control additive in an amount in the range of from about
0.1% to about 15% by weight of the fluid loss control additive.
69. The method of claim 66 wherein the fluid loss control additive
further comprises an organic acid, a deaggregation agent, silica,
or a combination thereof.
70. The method of claim 47 wherein the fluid loss control additive
further comprises a shale.
71. The method of claim 70 wherein the shale comprises vitrified
shale.
72. The method of claim 70 wherein the fluid loss control additive
further comprises a deaggregation agent, silica, or a combination
thereof.
73. The method of claim 72 wherein the silica is high surface area
amorphous silica.
74. The method of claim 73 wherein the high surface area amorphous
silica is present in the fluid loss control additive in an amount
sufficient to provide a desired after-set compressive strength.
75. The method of claim 47 wherein the fluid loss control additive
is present in the cement composition in an amount in the range of
from about 0.01% to about 5% by weight of cement.
76. The method of claim 47 wherein the acrylic acid copolymer
derivative is present in the fluid loss control additive in an
amount in the range of from about 30% to about 60% by weight.
77. The method of claim 47 wherein the fluid loss control additive
is present in the cement composition in an amount in the range of
from about 0.01% to about 5% by weight of cement, the iron compound
is present in the fluid loss control additive in an amount in the
range of from about 10% to about 15% by weight of the fluid loss
control additive, the hydratable polymer is present in the fluid
loss control additive in an amount in the range of from about 1% to
about 5% by weight of the fluid loss control additive, and the
dispersant is present in the fluid loss control additive in an
amount in the range of from about 20% to about 45% by weight of the
fluid loss control additive.
78. A cement composition comprising a cement, water, and a fluid
loss control additive, the fluid loss control additive comprising:
an acrylic acid copolymer derivative; an iron compound; and at
least one of a dispersant or a hydratable polymer.
79. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a copolymer or a copolymer salt that
comprises first monomers formed from N,N-dimethylacrylamide, and
second monomers formed from 2-acrylamido-2-methylpropane sulfonic
acid or a derivative thereof.
80. The cement composition of claim 79 wherein the copolymer or the
copolymer salt has a N,N-dimethylacrylamide to
2-acrylamido-2-methylpropa- ne sulfonic acid or a derivative
thereof mole ratio of from about 1:4 to about 4:1.
81. The cement composition of claim 79 wherein the copolymer or the
copolymer salt has a weight average molecular weight of between
about 75,000 daltons and about 300,000 daltons.
82. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a graft polymer comprising a
backbone comprising at least one of a lignin, a lignite, or their
salts and a grafted pendant group comprising monomers formed from
at least one of 2-acrylamido-2-methylpropane sulfonic acid,
acrylonitrile, N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylat- e.
83. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a graft polymer comprising a
backbone comprising at least one of derivatized cellulose,
polyvinyl alcohol, polyethylene oxide, or polypropylene oxide, and
a grafted pendant group comprising monomers formed from at least
one of 2-acrylamido-2-methylpropane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
84. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a copolymer or a copolymer salt
comprising first monomers formed from 2-acrylamido-2-methylpropane
sulfonic acid or a derivative thereof.
85. The cement composition of claim 84 wherein the copolymer or the
copolymer salt comprises first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof,
second monomers formed from maleic acid or a salt thereof, third
monomers formed from N-vinyl caprolactam, and fourth monomers
formed from 4-hydroxybutyl vinyl ether.
86. The cement composition of claim 84 wherein the copolymer or the
copolymer salt comprises a copolymer comprising first monomers
formed from 2-acrylamido-2-methylpropane sulfonic acid or a
derivative thereof, and second monomers formed from hydrolyzed
acrylamide.
87. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a copolymer or copolymer salt
comprising a waffle tannin having monomers formed from at least one
of 2-acrylamido-2-methylpropane sulfonic acid or acrylamide grafted
thereto.
88. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises 1 part by weight of a polymer
comprising 70 mole % of AMPS, 17 mole % of N, N-dimethylacrylamide,
and 13 mole % of acrylamide, and 2 parts by weight of
hydroxyethylcellulose having 1.5 moles of ethylene oxide
substitution.
89. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative comprises a copolymer or copolymer salt of a
vinylamide morpholine derivative and least one branched
N-vinylamide derivative, wherein the vinylamide morpholine
derivative is selected from compounds represented by the formula:
8wherein R.sub.1--H or --CH.sub.3 and R.sub.2 is --H, --CH.sub.3,
or --CH.sub.2CH.sub.3 and is positioned on any of the four carbon
atoms in the morpholine ring, and the N-vinylamide derivative is
selected from the compounds represented by the formula: 9wherein
R.sub.3 is R.sub.1--H or --CH.sub.3; R.sub.4 is --H, --CH.sub.3,
--CH.sub.2CH.sub.3, --CH(CH.sub.3).sub.2, --(CH.sub.3).sub.3, or
--CH(CH.sub.3).sub.2SO.sub.3X, wherein X is --Na, --NH.sub.4, or
--Ca1/2, and R.sub.5 is --H, --CH.sub.3, or --CH.sub.2CH.sub.3.
90. The cement composition of claim 89 wherein the vinylamide
derivative is acryloylmorpholine, and the branched N-vinylamide
derivative is a sodium salt of 2-acrylamido-2-methylpropanesulfonic
acid.
91. The cement composition of claim 89 wherein the vinylamide
derivative is acryloylmorpholine, a first vinylamide derivative is
a sodium salt of 2-acrylamido-2-methylpropanesulfonic acid, and a
second vinylamide derivative is acrylamide.
92. The cement composition of claim 78 wherein the hydratable
polymer comprises carboxymethylcellulose, hydroxyethylcellulose,
carboxymethylhydroxyethylcellulose, a vinyl sulfonated polymer, a
hydratable graft polymer, or a mixture thereof.
93. The cement composition of claim 78 wherein the hydratable
polymer is present in the fluid loss control additive in an amount
in the range of from about 0.1% to about 15% by weight of the fluid
loss control additive.
94. The cement composition of claim 78 wherein the dispersant
comprises a sodium salt of napthalene sulfonic acid, or a
water-soluble polymer prepared by the caustic-catalyzed
condensation of formaldehyde with acetone wherein the polymer
contains sodium sulfate groups.
95. The cement composition of claim 78 wherein the dispersant is
present in the fluid loss control additive in an amount sufficient
to prevent gelation of the cement composition.
96. The cement composition of claim 78 wherein the dispersant is
present in the fluid loss control additive in an amount in the
range of from about 5% to about 70% by weight of the fluid loss
control additive.
97. The cement composition of claim 78 wherein the iron compound is
present in the fluid loss control additive in an amount in the
range of from about 5% to about 25% by weight of the fluid loss
control additive.
98. The cement composition of claim 78 wherein the iron compound is
present in the fluid loss control additive in an amount in the
range of from about 10% to about 15% by weight of the fluid loss
control additive.
99. The cement composition of claim 78 wherein the iron compound is
an iron chloride or an iron gluconate.
100. The cement composition of claim 99 wherein the iron chloride
is ferrous chloride, ferric chloride, or a mixture thereof.
101. The cement composition of claim 78 wherein the fluid loss
control additive further comprises a zeolite.
102. The cement composition of claim 101 wherein the zeolite
further comprises chabazite and amorphous silica.
103. The cement composition of claim 101 wherein the zeolite is
present in the fluid loss control additive in an amount in the
range of from about 0.1% to about 15% by weight of the fluid loss
control additive.
104. The cement composition of claim 101 wherein the fluid loss
control additive further comprises an organic acid, a deaggregation
agent, silica, or a combination thereof.
105. The cement composition of claim 78 wherein the fluid loss
control additive further comprises a shale.
106. The cement composition of claim 105 wherein the shale
comprises vitrified shale.
107. The cement composition of claim 105 wherein the shale is
present in the fluid loss control additive in an amount in the
range of from about 0.1% to about 15% by weight of the fluid loss
control additive.
108. The cement composition of claim 105 wherein the fluid loss
control additive further comprises an organic acid, a deaggregation
agent, silica, or a combination thereof.
109. The cement composition of claim 108 wherein the organic acid
is present in the fluid loss control additive in an amount
sufficient to provide a desired degree of viscosity control.
110. The cement composition of claim 108 wherein the organic acid
is present in the fluid loss control additive in an amount in the
range of from about 0.01% to about 5% by weight of the fluid loss
control additive.
111. The cement composition of claim 108 wherein the deaggregation
agent is present in the fluid loss control additive in an amount
sufficient to enable the fluid loss control additive to flow freely
as a powder.
112. The cement composition of claim 108 wherein the deaggregation
agent is present in the fluid loss control additive in an amount in
the range of from about 1% to about 15% by weight of the fluid loss
control additive.
113. The cement composition of claim 108 wherein the silica is high
surface area amorphous silica.
114. The cement composition of claim 113 wherein the high surface
area amorphous silica is present in the fluid loss control additive
in an amount sufficient to provide a desired after-set compressive
strength.
115. The cement composition of claim 113 wherein the high surface
area amorphous silica is present in the fluid loss control additive
in an amount in the range of from about 0.1% to about 15% by weight
of the fluid loss control additive.
116. The cement composition of claim 78 wherein the cement
comprises a Portland cement, a pozzolanic cement, a gypsum cement,
a high alumina content cement, a silica cement, or a high
alkalinity cement.
117. The cement composition of claim 78 wherein the water is
present in the cement composition in an amount sufficient to form a
pumpable slurry.
118. The cement composition of claim 78 wherein the water is
present in the cement composition in an amount in the range of from
about 15% to about 200% by weight of cement.
119. The cement composition of claim 78 wherein the cement
composition has a density in the range of from about 5 pounds per
gallon to about 30 pounds per gallon.
120. The cement composition of claim 78 wherein the cement
composition further comprises a weighting agent, a defoamer, a
surfactant, mica, fiber, bentonite, microspheres, fumed silica, a
salt, vitrified shale, fly ash, a dispersant, a retardant, or an
accelerant.
121. The cement composition of claim 78 wherein the fluid loss
control additive is present in the cement composition in an amount
sufficient to provide a desired degree of fluid loss control.
122. The cement composition of claim 78 wherein the fluid loss
control additive is present in the cement composition in an amount
in the range of from about 0.01% to about 5% by weight of
cement.
123. The cement composition of claim 78 wherein the acrylic acid
copolymer derivative is present in the fluid loss control additive
in an amount in the range of from about 1% to about 99% by
weight.
124. The cement composition of claim 78 wherein the fluid loss
control additive is present in the cement composition in an amount
in the range of from about 0.01% to about 5% by weight of cement,
the iron compound is present in the fluid loss control additive in
an amount in the range of from about 10% to about 15% by weight of
the fluid loss control additive, the hydratable polymer is present
in the fluid loss control additive in an amount in the range of
from about 1% to about 5% by weight of the fluid loss control
additive, and the dispersant is present in the fluid loss control
additive in an amount in the range of from about 20% to about 45%
by weight of the fluid loss control additive.
125. A fluid loss control additive comprising: an acrylic acid
copolymer derivative; an iron compound; and at least one of a
dispersant or a hydratable polymer.
126. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a copolymer or a
copolymer salt that comprises first monomers formed from
N,N-dimethylacrylamide, and second monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative
thereof.
127. The fluid loss control additive of claim 126 wherein the
copolymer or the copolymer salt has a N,N-dimethylacrylamide to
2-acrylamido-2-methylpropane sulfonic acid or a derivative thereof
mole ratio of from about 1:4 to about 4:1.
128. The fluid loss control additive of claim 126 wherein the
copolymer or the copolymer salt has a weight average molecular
weight of between about 75,000 daltons and about 300,000
daltons.
129. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a graft polymer
comprising a backbone comprising at least one of a lignin, a
lignite, or their salts and a grafted pendant group comprising
monomers formed from at least one of 2-acrylamido-2-methylpropane
sulfonic acid, acrylonitrile, N,N-dimethylacrylamide, acrylic acid,
or N,N-dialkylaminoethylmethacrylat- e.
130. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a graft polymer
comprising a backbone comprising at least one of derivatized
cellulose, polyvinyl alcohol, polyethylene oxide, or polypropylene
oxide, and a grafted pendant group comprising monomers formed from
at least one of 2-acrylamido-2-methylprop- ane sulfonic acid,
acrylonitrile, N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate.
131. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a copolymer or a
copolymer salt comprising first monomers formed from
2-acrylamido-2-methylpropane sulfonic acid or a derivative
thereof.
132. The fluid loss control additive of claim 131 wherein the
copolymer or the copolymer salt comprises first monomers formed
from 2-acrylamido-2-methylpropane sulfonic acid or a derivative
thereof, second monomers formed from maleic acid or a salt thereof,
third monomers formed from N-vinyl caprolactam, and fourth monomers
formed from 4-hydroxybutyl vinyl ether.
133. The fluid loss control additive of claim 131 wherein the
copolymer or the copolymer salt comprises a copolymer comprising
first monomers formed from 2-acrylamido-2-methylpropane sulfonic
acid or a derivative thereof, and second monomers formed from
hydrolyzed acrylamide.
134. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a copolymer or
copolymer salt comprising a waffle tannin having monomers formed
from at least one of 2-acrylamido-2-methylpropane sulfonic acid or
acrylamide grafted thereto.
135. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises 1 part by weight of a
polymer comprising 70 mole % of AMPS, 17 mole % of N,
N-dimethylacrylamide, and 13 mole % of acrylamide, and 2 parts by
weight of hydroxyethylcellulose having 1.5 moles of ethylene oxide
substitution.
136. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative comprises a copolymer or
copolymer salt of a vinylamide morpholine derivative and least one
branched N-vinylamide derivative, wherein the vinylamide morpholine
derivative is selected from compounds represented by the formula:
10wherein R.sub.1--H or --CH.sub.3 and R.sub.2 is --H, --CH.sub.3,
or --CH.sub.2CH.sub.3 and is positioned on any of the four carbon
atoms in the morpholine ring, and the N-vinylamide derivative is
selected from the compounds represented by the formula: 11wherein
R.sub.3 is R.sub.1--H or --CH.sub.3; R.sub.4 is --H, --CH.sub.3,
--CH.sub.2CH.sub.3, --CH(CH.sub.3).sub.2, --C(CH.sub.3).sub.3, or
--CH(CH.sub.3).sub.2SO.sub.3X, wherein X is --Na, --NH.sub.4, or
--Ca1/2, and R.sub.5 is --H, --CH.sub.3, or --CH.sub.2CH.sub.3.
137. The fluid loss control additive of claim 136 wherein the
vinylamide derivative is acryloylmorpholine and the branched
N-vinylamide derivative is a sodium salt of
2-acrylamido-2-methylpropanesulfonic acid.
138. The fluid loss control additive of claim 136 wherein the
vinylamide derivative is acryloylmorpholine, a first vinylamide
derivative is a sodium salt of 2-acrylamido-2-methylpropanesulfonic
acid, and a second vinylamide derivative is acrylamide.
139. The fluid loss control additive of claim 125 wherein the
hydratable polymer comprises carboxymethylcellulose,
hydroxyethylcellulose, carboxymethylhydroxyethylcellulose, a vinyl
sulfonated polymer, a hydratable graft polymer, or a mixture
thereof.
140. The fluid loss control additive of claim 125 wherein the
hydratable polymer is present in the fluid loss control additive in
an amount in the range of from about 0.1% to about 15% by weight of
the fluid loss control additive.
141. The fluid loss control additive of claim 125 wherein the
dispersant comprises a sodium salt of napthalene sulfonic acid, or
a water-soluble polymer prepared by the caustic-catalyzed
condensation of formaldehyde with acetone wherein the polymer
contains sodium sulfate groups.
142. The fluid loss control additive of claim 125 wherein the
dispersant is present in the fluid loss control additive in an
amount sufficient to prevent gelation of the fluid loss control
additive.
143. The fluid loss control additive of claim 125 wherein the
dispersant is present in the fluid loss control additive in an
amount in the range of from about 5% to about 70% by weight of the
fluid loss control additive.
144. The fluid loss control additive of claim 125 wherein the iron
compound is present in the fluid loss control additive in an amount
in the range of from about 5% to about 25% by weight of the fluid
loss control additive.
145. The fluid loss control additive of claim 125 wherein the iron
compound is an iron chloride or an iron gluconate.
146. The fluid loss control additive of claim 145 wherein the iron
chloride is ferrous chloride, ferric chloride, or a mixture
thereof.
147. The fluid loss control additive of claim 125 wherein the fluid
loss control additive further comprises a zeolite.
148. The fluid loss control additive of claim 147 wherein the
zeolite further comprises chabazite and amorphous silica.
149. The fluid loss control additive of claim 147 wherein the
zeolite is present in the fluid loss control additive in an amount
in the range of from about 0.1% to about 15% by weight of the fluid
loss control additive.
150. The fluid loss control additive of claim 147 wherein the fluid
loss control additive further comprises an organic acid, a
deaggregation agent, silica, or a combination thereof.
151. The fluid loss control additive of claim 125 wherein the fluid
loss control additive further comprises a shale.
152. The fluid loss control additive of claim 151 wherein the shale
comprises vitrified shale.
153. The fluid loss control additive of claim 151 wherein the shale
is present in the fluid loss control additive in an amount in the
range of from about 0.1% to about 15% by weight of the fluid loss
control additive.
154. The fluid loss control additive of claim 151 wherein the fluid
loss control additive further comprises an organic acid, a
deaggregation agent, silica, or a combination thereof.
155. The fluid loss control additive of claim 154 wherein the
organic acid is present in the fluid loss control additive in an
amount sufficient to provide a desired degree of viscosity
control.
156. The fluid loss control additive of claim 154 wherein the
organic acid is present in the fluid loss control additive in an
amount in the range of from about 0.01% to about 5% by weight of
the fluid loss control additive.
157. The fluid loss control additive of claim 154 wherein the
deaggregation agent is present in the fluid loss control additive
in an amount sufficient to enable the fluid loss control additive
to flow freely as a powder.
158. The fluid loss control additive of claim 154 wherein the
deaggregation agent is present in the fluid loss control additive
in an amount in the range of from about 1% to about 15% by weight
of the fluid loss control additive.
159. The fluid loss control additive of claim 154 wherein the
silica is high surface area amorphous silica.
160. The fluid loss control additive of claim 159 wherein the high
surface area amorphous silica is present in the fluid loss control
additive in an amount sufficient to provide a desired after-set
compressive strength.
161. The fluid loss control additive of claim 159 wherein the high
surface area amorphous silica is present in the fluid loss control
additive in an amount in the range of from about 0.1% to about 15%
by weight of the fluid loss control additive.
162. The fluid loss control additive of claim 125 wherein the
acrylic acid copolymer derivative is present in the fluid loss
control additive in an amount in the range of from about 1% to
about 99% by weight.
163. The fluid loss control additive of claim 125 wherein the fluid
loss control additive is present in the cement composition in an
amount in the range of from about 0.01% to about 5% by weight of
cement, the iron compound is present in the fluid loss control
additive in an amount in the range of from about 10% to about 15%
by weight of the fluid loss control additive, the hydratable
polymer is present in the fluid loss control additive in an amount
in the range of from about 1% to about 5% by weight of the fluid
loss control additive, and the dispersant is present in the fluid
loss control additive in an amount in the range of from about 20%
to about 45% by weight of the fluid loss control additive.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 10/891,384 entitled "Compositions Comprising
Set Retarder Compositions and Associated Methods," filed on Jul.
14, 2004, which is a continuation-in-part of U.S. application Ser.
No. 10/608,748 entitled "Cement Compositions With Improved Fluid
Loss Characteristics and Methods of Cementing in Surface and
Subterranean Applications," filed on Jun. 27, 2003.
BACKGROUND
[0002] The present invention relates to cementing operations, and
more particularly, to cement compositions comprising an improved
fluid loss control additive, and methods of using such compositions
in surface and subterranean applications.
[0003] Hydraulic cement compositions are commonly utilized in
subterranean operations, particularly subterranean well completion
and remedial operations. For example, hydraulic cement compositions
are used in primary cementing operations whereby pipe strings such
as casings and liners are cemented in well bores. In performing
primary cementing, hydraulic cement compositions are pumped into
the annular space between the walls of a well bore and the exterior
surface of the pipe string disposed therein. The cement composition
is permitted to set in the annular space, thereby forming an
annular sheath of hardened substantially impermeable cement therein
that substantially supports and positions the pipe string in the
well bore and bonds the exterior surface of the pipe string to the
walls of the well bore. Hydraulic cement compositions also are used
in remedial cementing operations such as plugging highly permeable
zones or fractures in well bores, plugging cracks and holes in pipe
strings, and the like.
[0004] For such well cementing operations to be successful, the
cement compositions utilized should include a fluid loss control
additive to reduce the loss of fluid, e.g., water, from the cement
compositions when they contact permeable subterranean formations
and zones. Excessive fluid loss, inter alia, causes a cement
composition to be prematurely dehydrated, which limits the amount
of cement composition that can be pumped, decreases the compressive
strength of the set cement composition, and prevents or reduces
bond strength between the set cement composition and the
subterranean zone, the walls of pipe, and/or the walls of the well
bore. Fluid loss control agents may also be used in surface cement
compositions.
[0005] Conventional contemporary synthetic fluid loss control
additives are large, water-soluble polymers that are capable of
functioning at a wider range of temperatures. An example of such
synthetic fluid loss control additive is a fluid loss control
additive consisting of hydrolyzed copolymers of acrylamide ("AA")
and 2-acrylamido-2-methylpropa- ne sulfonic acid ("AMPS"). However,
certain of these AA/AMPS copolymers are useful only in operations
where the bottom hole circulating temperature ("BHCT") ranges from
about 90.degree. F. to about 125.degree. F., whereas BHCT ranges
encountered in such operations are often outside such a range.
Still further, certain of these copolymers have a salt tolerance of
only up to about 10%.
[0006] The temperature limitations of certain of the AA/AMPS
copolymers, e.g., ineffectiveness at temperatures above about
125.degree. F. BHCT, are believed to be the result of hydrolysis of
the amide groups. The carboxylate groups formed by such hydrolysis
convert the copolymers to materials, which lead to retarding of the
setting of the cement and losses in the compressive strength of the
set cement. Further, in the lower portion of the above-mentioned
temperature range (between about 90.degree. F. to about 100
.degree. F.), certain of the AA/AMPS copolymers are less effective
as a fluid loss control additive, requiring inclusion of larger
amounts of the AA/AMPS copolymers than at higher temperatures. The
inclusion of a sufficiently large amount of a fluid loss control
additive to create a cement composition with acceptable fluid loss
often creates viscosity and pumpability problems, since the
addition of such copolymer directly affects the resultant slurry
rheology. Certain AA/AMPS copolymers exhibit high viscosity and
poor mixability, resulting in cement slurries having poor
pumpability characteristics during cementing operations. Mixability
is a subjective term used to describe how well the components in
the cement composition wet and mix with each other, as well as the
energy required to create a generally homogeneous slurry.
SUMMARY
[0007] The present invention relates to cementing operations, and
more particularly, to cement compositions comprising an improved
fluid loss control additive, and methods of using such compositions
in surface and subterranean applications.
[0008] In one embodiment, the present invention provides a cement
composition that comprises a cement, water, and a fluid loss
control additive, the fluid loss control additive comprising an
acrylic acid copolymer derivative, an iron compound, and at least
one of a dispersant or a hydratable polymer.
[0009] In another embodiment, the present invention provides a
fluid loss control additive that comprises an acrylic acid
copolymer derivative, an iron compound, and at least one of a
dispersant or a hydratable polymer.
[0010] In another embodiment, the present invention provides a
method of cementing in a subterranean formation that comprises
providing a cement composition comprising a cement, water, and a
fluid loss control additive, the fluid loss control additive
comprising an acrylic acid copolymer derivative, an iron compound,
and at least one of a hydratable polymer or a dispersant; placing
the cement composition into the subterranean formation; and
permitting the cement composition to set therein.
[0011] In yet another embodiment, the present invention provides a
method of reducing the fluid loss from a cement composition that
comprises adding to the cement composition a fluid loss control
additive comprising an acrylic acid copolymer derivative, an iron
compound, and at least one of a dispersant or a hydratable
polymer.
[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 the specific embodiments, which
follows.
DESCRIPTION
[0013] The present invention relates to cementing operations, and
more particularly, to cement compositions comprising an improved
fluid loss control additive, and methods of using such compositions
in surface and subterranean applications. While the compositions
and methods of the present invention are useful in a variety of
applications, they are particularly useful for subterranean well
completion and remedial operations, such as primary cementing,
e.g., cementing casings and liners in well bores, including those
in production wells, which include multi-lateral subterranean
wells. They are also useful for surface cementing operations,
including construction cementing operations.
[0014] The cement compositions of the present invention generally
comprise a cement, water, and a fluid loss control additive of the
present invention. A wide variety of optional additives may be
included in the cement compositions of the present invention if
desired. The cement compositions of the present invention may range
in density from about 5 lb/gallon to about 30 lb/gallon. In one
embodiment, the cement compositions of the present invention range
in density from about 8 lb/gallon to about 20 lb/gallon.
[0015] Any cements suitable for use in subterranean applications
are suitable for use in the present invention. Furthermore, any
cements suitable for use in surface applications, e.g.,
construction cements, are suitable for use in the present
invention. In one embodiment, the improved cement compositions of
the present invention comprise a hydraulic cement. A variety of
hydraulic cements are suitable for use, including those comprised
of calcium, aluminum, silicon, oxygen, and/or sulfur, which set and
harden by reaction with water. Such hydraulic cements include, but
are not limited to, Portland cements, pozzolanic cements, gypsum
cements, high alumina content cements, silica cements, and high
alkalinity cements.
[0016] The water present in the cement compositions of the present
invention may be from any source, provided that it does not contain
an excess of compounds that adversely affect other compounds in the
cement compositions. For example, a cement composition of the
present invention can comprise fresh water, saltwater (e.g., water
containing one or more salts dissolved therein), brine (e.g.,
saturated saltwater), or seawater. The water may be present in an
amount sufficient to form a pumpable slurry. Generally, the water
is present in the cement compositions of the present invention in
an amount in the range of from about 15% to about 200% by weight of
cement ("bwoc") therein. In certain embodiments, the water is
present in the cement compositions of the present invention in an
amount in the range of from about 25% to about 60% bwoc
therein.
[0017] The fluid loss control additives of the present invention
generally comprise an acrylic acid copolymer derivative, an iron
compound, and at least one of a hydratable polymer or a dispersant.
Certain embodiments comprise an acrylic acid copolymer derivative,
an iron compound, and a hydratable polymer. Certain other
embodiments comprise an acrylic acid copolymer derivative, an iron
compound, and a dispersant. Optionally, the fluid loss control
additives of the present invention may further comprise zeolites,
shales, organic acids, deaggregation agents, or combinations
thereof.
[0018] The fluid loss control additives of the present invention
comprise an acrylic acid copolymer derivative. As referred to
herein, the term "copolymer" will be understood to mean a polymer
comprising two or more different compounds. For example, a
"copolymer" may comprise, inter alia, a graft polymer wherein one
monomer is grafted onto a backbone comprising another monomer. Any
copolymer or copolymer salt of acrylic acid or a derivative thereof
will be an "acrylic acid copolymer derivative" as that term is used
herein. Examples of suitable acrylic acid derivatives include, but
are not limited to, acrylamides, acrylates, acrylonitrile, AMPS,
N,N-dimethylacrylamide, N,N-dialkylaminoethylmethacrylate, and acid
salts thereof. An example of a suitable acrylic acid copolymer
derivative comprises a copolymer, or copolymer salt, comprising
first monomers formed from N,N-dimethylacrylamide and second
monomers formed from AMPS or derivatives thereof (e.g., acid salts
of AMPS). Generally, monomers formed from AMPS or derivatives
thereof are represented by formula (1): 1
[0019] wherein M is hydrogen, ammonium, sodium, or potassium.
[0020] Another example of a suitable acrylic acid copolymer
derivative comprises a graft polymer comprising a backbone
comprising at least one of a lignin, a lignite, or their salts, and
a grafted pendant group comprising monomers formed from at least
one of 2-acrylamido-2-methylprop- ane sulfonic acid, acrylonitrile,
N,N-dimethylacrylamide, acrylic acid, or
N,N-dialkylaminoethylmethacrylate. Another example of a suitable
acrylic acid copolymer derivative comprises a graft polymer
comprising a backbone comprising at least one of derivatized
cellulose, polyvinyl alcohol, polyethylene oxide, polypropylene
oxide, and a grafted pendant group comprising monomers formed from
at least one of AMPS, acrylonitrile, N,N-dimethylacrylamide,
acrylic acid, or N,N-dialkylaminoethylmethacrylat- e. In these
embodiments, the alkyl groups in the N,N-dialkylaminoethylmeth-
acrylate may comprise at least one of methyl, ethyl, or propyl
radicals. Another example of a suitable acrylic acid copolymer
derivative comprises copolymers, or copolymer salts, comprising
first monomers formed from AMPS or derivatives thereof, second
monomers formed from maleic acid or salts thereof, third monomers
formed from N-vinyl caprolactam, and fourth monomers formed from
4-hydroxybutyl vinyl ether. An additional example of a suitable
acrylic acid copolymer derivative comprises copolymers, or
copolymer salts, comprising first monomers formed from AMPS or
derivatives thereof and second monomers formed from hydrolyzed
acrylamide. In these embodiments, the acrylamide may be either
completely or partially hydrolyzed. Another example of a suitable
acrylic acid copolymer derivative comprises copolymers, or
copolymer salts, comprising a waffle tannin grafted with at least
one backbone having monomers formed from at least one of AMPS or
acrylamide grafted thereto. Yet another example of a suitable
acrylic acid copolymer derivative comprises a polymer complex
comprising 1 part by weight of a polymer comprising 70 mole % of
AMPS, 17 mole % of N, N-dimethylacrylamide, and 13 mole % of
acrylamide, and 2 parts by weight of hydroxyethylcellulose having
1.5 moles of ethylene oxide substitution. In one embodiment, an
acrylic acid copolymer derivative of the present invention
comprises a copolymer, or copolymer salt, of a vinylamide
morpholine derivative and least one branched N-vinylamide
derivative. Generally, the vinylamide morpholine derivatives that
may be present in the copolymer, or copolymer salt, are selected
from compounds represented by formula (2): 2
[0021] wherein R.sub.1--H or --CH.sub.3 and R.sub.2 is --H,
--CH.sub.3, or --CH.sub.2CH.sub.3 and is positioned on any of the
four carbon atoms in the morpholine ring. Generally, the
N-vinylamide derivatives that may be present in copolymer, or
copolymer salt, are selected from the compounds represented by
formula (3): 3
[0022] wherein R.sub.3 is R.sub.1--H or --CH.sub.3; R.sub.4 is --H,
--CH.sub.3, --CH.sub.2CH.sub.3, --CH(CH.sub.3).sub.2,
--C(CH.sub.3).sub.3, or --CH(CH.sub.3).sub.2SO.sub.3X, wherein X is
--Na, --NH.sub.4, or --Ca1/2, and R.sub.5 is --H, --CH.sub.3, or
--CH.sub.2CH.sub.3. In one certain embodiment, the vinylamide
derivative is acryloylmorpholine and the branched N-vinylamide
derivative is the sodium salt of AMPS. In another embodiment, the
vinylamide derivative is acryloylmorpholine and a first vinylamide
derivative is the sodium salt of AMPS and a second vinylamide
derivative is acrylamide.
[0023] Generally, the acrylic acid copolymer derivatives included
in the fluid loss control additives of the present invention may be
manufactured in accordance with any suitable technique for polymer
manufacture, such as a variety of techniques for free radical
polymerization. Examples of suitable acrylic acid copolymer
derivatives are described in U.S. Pat. Nos. 4,015,991; 4,515,635;
4,555,269; 4,676,317; 4,703,801; 5,134,215; 5,147,964; 5,134,215;
5,986,276; 6,085,840; 6,089,318, 6,268,406; 6,715,552; and
6,767,867, the relevant disclosures of which are incorporated
herein by reference. Examples of suitable commercially available
acrylic acid copolymer derivatives include, inter alia, those
commercially available from Halliburton Energy Services, Inc.,
Duncan, Okla., under the trade names "HALAD.RTM.-344";
"HALAD.RTM.-413"; "HALAD.RTM.-4," "HALAD.RTM.-567" and
"HALAD.RTM.-700". In certain embodiments where the acrylic acid
copolymer derivative comprises a copolymer or copolymer salt of
N,N-dimethylacrylamide and AMPS or derivatives thereof, the
copolymer, or copolymer salt, may have a N,N-dimethylacrylamide to
AMPS (or derivatives thereof) mole ratio of from about 1:4 to about
4:1. In certain embodiments, the copolymer, or copolymer salt, may
have a weight average molecular weight of between about 75,000
daltons and about 300,000 daltons.
[0024] Generally, the acrylic acid copolymer derivative may be
present in the fluid loss control additives of the present
invention in an amount in the range of from about 1% to about 99%
by weight. In one embodiment, the acrylic acid copolymer derivative
is present in the fluid loss control additive in an amount in the
range of from about 30% to about 60% by weight.
[0025] Certain embodiments of the fluid loss control additives of
the present invention may comprise a dispersant. Where present, the
dispersant in the fluid loss control additive acts, inter alia, to
control the rheology of the cement composition and to stabilize the
cement composition over a broad density range. While a variety of
dispersants known to those skilled in the art may be used in
accordance with the present invention, one suitable dispersant is a
water-soluble polymer prepared by the caustic-catalyzed
condensation of formaldehyde with acetone wherein the polymer
contains sodium sulfate groups. Such a dispersant is commercially
available under the trade designation "CFR-3.TM." from Halliburton
Energy Services, Inc., Duncan, Okla. Another suitable dispersant is
a sodium salt of napthalene sulfonic acid, which is commercially
available under the trade designation "CFR-2.TM.," also from
Halliburton Energy Services, Inc., Duncan, Okla. Another source of
a suitable dispersant is a multi-purpose cement additive
commercially available under the trade designation "UNIVERSAL
CEMENT SYSTEMS.TM." from Halliburton Energy Services, Inc., Duncan,
Okla.; such additive is disclosed in U.S. Pat. Nos. 5,749,418;
5,968,255; and 5,972,103, the relevant disclosures of which are
incorporated herein by reference. Generally, in some embodiments,
Universal Cement Systems.TM. multi-purpose cement additive may
comprise in the range of from about 5% to about 70% of a dispersant
by weight. Where used, the dispersant is present in the fluid loss
control additive of the present invention in an amount sufficient
to prevent gelation of the cement composition. In some embodiments,
the dispersant is present in the fluid loss control additive of the
present invention in an amount in the range of from about 5% to
about 70% by weight. In one embodiment, the dispersant is present
in the fluid loss control additive of the present invention in an
amount in the range of from about 20% to about 40% by weight.
[0026] Certain embodiments of the fluid loss control additives of
the present invention may comprise a hydratable polymer. Where
present, the hydratable polymer in the fluid loss control additive
acts, inter alia, to increase the viscosity of the cement
composition in which the fluid loss control additive is used.
Various hydratable polymers can be utilized in the fluid loss
control additive, including, but not limited to,
carboxymethylcellulose, hydroxyethylcellulose,
carboxymethylhydroxyethylcellulose, vinyl sulfonated polymers, and
hydratable graft polymers. An example of a suitable hydratable
polymer is a cellulose derivative commercially available from Dow
Chemical Co., under the trade name "CARBOTRON 20." Another source
of a suitable hydratable polymer is a multi-purpose cement additive
commercially available under the trade dsignation "UNIVERSAL CEMENT
SYSTEMS.TM." from Halliburton Energy Services, Inc., Duncan, Okla.;
such additive is disclosed in U.S. Pat. Nos. 5,749,418; 5,968,255;
and 5,972,103, the relevant disclosures of which are herein
incorporated by reference. Generally, in some embodiments, the
Universal Cement Systems.TM. multi-purpose cement additive may
comprise in the range from about 1% to about 20% of a hydratable
polymer by weight. Where utilized, the hydratable polymer is
present in the fluid loss control additive of the present invention
in an amount sufficient to contribute a desired degree of viscosity
to the cement composition. Generally, the hydratable polymer is
present in the fluid loss control additive of the present invention
in an amount in the range of from about 0.1% to about 15% by
weight. In one embodiment, the hydratable polymer is present in the
fluid loss control additive of the present invention in an amount
in the range of from about 1% to about 5% by weight.
[0027] Optionally, the fluid loss control additives of the present
invention may comprise a zeolite. Where used, the zeolite
functions, inter alia, to improve the suspension of the fluid loss
control additive in a cement slurry. The zeolite further comprises
a mixture of chabazite and amorphous silica. The chabazite is
present in the zeolite in an amount in the range of from about 50%
by weight to about 75% by weight. In certain embodiments, the
chabazite is present in the zeolite in an amount in the range of
from about 65% by weight to about 70% by weight. The amorphous
silica is generally present in the zeolite in an amount in the
range of from about 25% by weight to about 50% by weight. In
certain embodiments, the amorphous silica is present in the zeolite
in an amount in the range of from about 30% by weight to about 35%
by weight. An example of a suitable source of zeolite is available
from the C2C Zeolite Corporation of Calgary, Canada. Where used,
the zeolite is generally present in the fluid loss control additive
of the present invention in an amount in the range of from about
0.1% by weight to about 15% by weight. In certain embodiments, the
zeolite is present in the fluid loss control additive of the
present invention in an amount in the range of from about 3% by
weight to about 7% by weight.
[0028] The fluid loss control additives of the present invention
also may optionally comprise shale. Where used, the shale
functions, inter alia, to improve the ability of the fluid loss
control additives of the present invention to flow freely as a
powder. A variety of shales are suitable, including those comprised
of silicon, aluminum, calcium, and/or magnesium. In some
embodiments, the shale comprises vitrified shale. In certain
embodiments, the vitrified shale may be fine grain vitrified shale,
wherein the fine grain vitrified shale has a particle size
distribution in the range of from about 2 micrometers to about
4,750 micrometers. An example of a suitable fine grain vitrified
shale is "PRESSURE-SEAL.RTM. FINE LCM," which is commercially
available from TXI Energy Services, Inc., Houston, Tex. In another
embodiment, the vitrified shale may be coarse grain vitrified
shale, wherein the coarse vitrified shale particles may have a
particle size distribution in the range of from about 2 micrometers
to about 4,750 micrometers. An example of a suitable coarse grain
vitrified shale is "PRESSUR-SEAL.RTM. COARSE LCM," which is
commercially available from TXI Energy Services, Inc., Houston,
Tex. Where used, the shale is generally present in the fluid loss
control additive of the present invention of the present invention
in an amount in the range of from about 0.1% to about 15% by
weight. In certain embodiments, the shale is present in the fluid
loss control additive of the present invention in an amount in the
range of from about 3% to about 7% by weight.
[0029] Optionally, in certain embodiments, the fluid loss control
additives of the present invention may comprise iron compounds.
Suitable iron compounds include any soluble iron compound that
functions, inter alia, in combination with other components that
may be present, to aid the cement composition in hydrating in a
predictable manner. Among other things, the iron compound may also
improve the compressive strength of the cement composition in which
it is used. Where used, the iron compound may be, among others, an
iron chloride or an iron gluconate. Generally, the iron chloride
may be ferrous chloride, ferric chloride, or mixtures thereof. In
one embodiment, the iron chloride used in the improved fluid loss
control additives of the present invention is anhydrous ferric
chloride. An example of a suitable source of anhydrous ferric
chloride is commercially available from BASF Corporation in
Germany. Another source of a suitable iron chloride is a
multi-purpose cement additive commercially available under the
trade designation "UNIVERSAL CEMENT SYSTEMS.TM." from Halliburton
Energy Services, Inc., Duncan, Okla.; such additive is disclosed in
U.S. Pat. Nos. 5,749,418; 5,968,255; and 5,972,103, the relevant
disclosures of which are herein incorporated by reference.
Generally, in some embodiments, Universal Cement Systems.TM.
multi-purpose cement additive may comprise in the range of from
about 0.5% to about 30% iron chloride by weight. Where used, the
iron compound is present in the fluid loss control additive of the
present invention in an amount sufficient to allow the cement to be
suitable for the subterranean environment of the well being
cemented. More particularly, the iron compound may be present in
the fluid loss control additive of the present invention of the
present invention in an amount in the range of from about 5% to
about 25% by weight. In certain embodiments, the iron chloride may
be present in the fluid loss control additive of the present
invention of the present invention in an amount in the range of
from about 10% to about 15% by weight.
[0030] In some embodiments, the fluid loss control additive of the
present invention may optionally comprise an organic acid. Where
present, the organic acid acts, inter alia, to maintain the
viscosity of the cement composition in which the fluid loss control
additive is used over a broad density range by helping to prevent
gelation of the cement composition. Various organic acids can be
utilized in the fluid loss control additive, including, but not
limited to, tartaric acid, citric acid, gluconic acid, oleic acid,
phosphoric acid, and uric acid. An example of a suitable organic
acid is commercially available from Halliburton Energy Services,
Inc., Duncan, Okla., under the trade name "HR.RTM.-25." A suitable
organic acid also may be included in Universal Cement Systems.TM.
multi-purpose cement additive in an amount in the range of from
about 0.01% to about 10% by weight. Other examples of suitable
organic acids include, for example, organic acids that should have
either minimal or no effect on retarding or accelerating the
setting of the cement. One of ordinary skill in the art, with the
benefit of this disclosure, will recognize the types of organic
acids that are appropriate for inclusion in the improved fluid loss
control additives of the present invention. Where used, the organic
acid is present in the fluid loss control additive of the present
invention in an amount sufficient to provide a desired degree of
viscosity control. Generally, the organic acid is present in the
fluid loss control additive of the present invention in an amount
in the range of from about 0.01% to about 5% by weight. In one
embodiment, the organic acid is present in the fluid loss control
additive of the present invention in an amount in the range of from
about 0.01% to about 2% by weight.
[0031] Optionally, the fluid loss control additive of the present
invention may contain a deaggregation agent. Where used, the
deaggregation agent functions, inter alia, to improve the ability
of the fluid loss control additive to flow freely as a powder. The
deaggregation agent may also contribute a minor source of silica to
the multi-purpose cement additive. An example of a suitable
deaggregation agent is commercially available from National Pigment
and Chemical Co. under the trade name Mica/Brite X150.
Alternatively, quartz or ground sand may be used, though the
spherical nature of Mica/Brite X150 particles is thought to
contribute to improved flow characteristics for the cement
composition. A suitable deaggregation agent also may be included in
Universal Cement Systems.TM. multi-purpose cement additive in an
amount in the range of from about 1% to about 30% by weight.
Generally, the deaggregation agent is present in the fluid loss
control additive of the present invention in an amount sufficient
to enable the fluid loss control additive of the present invention
to flow freely as a powder. In some embodiments, the deaggregation
agent is present in the fluid loss control additive of the present
invention in an amount in the range of from about 1% to about 15%
by weight. In one embodiment, the deaggregation agent is present in
the fluid loss control additive of the present invention in an
amount in the range of from about 1% to about 10% by weight.
[0032] Optionally, the fluid loss control additive of the present
invention may comprise a source of silica. Where present in the
fluid loss control additive, the silica assists in maintaining the
compressive strength of the cement composition after setting. An
example of a suitable source of high surface area amorphous silica
is commercially available from Halliburton Energy Services, Inc.,
Duncan, Okla., under the trade name "SILICALITE." A suitable source
of silica also may be included in Universal Cement Systems.TM.
multi-purpose cement additive in an amount in the range of from
about 1% to about 50% by weight. Where used, the high surface area
amorphous silica is present in the fluid loss control additive of
the present invention in an amount sufficient to provide a desired
after-set compressive strength. More particularly, the high surface
area amorphous silica is present in the fluid loss control additive
of the present invention in an amount in the range of from about
0.1% to about 15% by weight. In one embodiment, the high surface
area amorphous silica is present in the fluid loss control additive
of the present invention in an amount in the range of from about 1%
to about 5% by weight.
[0033] The improved fluid loss control additives of the present
invention may be prepared in a variety of forms, including, inter
alia, particulates, solutions, and suspensions. Generally, the
fluid loss control additives of the present invention are present
in the cement compositions of the present invention in an amount
sufficient to provide a desired level of fluid loss control. More
particularly, the fluid loss control additive of the present
invention may be present in the cement composition in an amount in
the range of from about 0.01% to about 10% bwoc. In certain
preferred embodiments, the fluid loss control additive of the
present invention is present in the cement composition in an amount
in the range of from about 0.01% to about 5% bwoc.
[0034] As will be recognized by those skilled in the art, the
cement compositions of this invention also can include additional
suitable additives, including, inter alia, accelerants, set
retarders, defoamers, microspheres, fiber, weighting materials,
salts, vitrified shale, fly ash, and the like. Any suitable
additive may be incorporated within the cement compositions of the
present invention. One of ordinary skill in the art, with the
benefit of this disclosure, will be able to recognize where a
particular additive is suitable for a particular application.
[0035] In one embodiment, the present invention provides a cement
composition that comprises a cement, water, and a fluid loss
control additive, the fluid loss control additive comprising an
acrylic acid copolymer derivative; an iron compound; and at least
one of a dispersant or a hydratable polymer.
[0036] In another embodiment, the present invention provides a
fluid loss control additive that comprises an acrylic acid
copolymer derivative; an iron compound; and at least one of a
dispersant or a hydratable polymer.
[0037] In another embodiment, the present invention provides a
method of cementing in a subterranean formation that comprises
providing a cement composition comprising a cement, water, and a
fluid loss control additive, the fluid loss control additive
comprising an acrylic acid copolymer derivative, an iron compound,
and at least one of a hydratable polymer or a dispersant; placing
the cement composition into the subterranean formation; and
permitting the cement composition to set therein.
[0038] In yet another embodiment, the present invention provides a
method of reducing the fluid loss from a cement composition that
comprises adding to the cement composition a fluid loss control
additive comprising an acrylic acid copolymer derivative; an iron
compound; and at least one of a dispersant or a hydratable
polymer.
[0039] To facilitate a better understanding of the present
invention, the following illustrative examples of certain
embodiments are given. In no way should such examples be read to
limit, or define, the scope of the invention.
EXAMPLE 1
[0040] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0041] Sample Composition No. 1 (comparative) comprises a 15.6
lb/gallon ("ppg") slurry of Texas Lehigh Class A cement, with no
fluid loss control additives. The fluid loss was found to be 1,574
cubic centimeters.
[0042] Sample Composition No. 2 (comparative) was prepared by
mixing 0.5% of Universal Cement Systems.TM. multi-purpose cement
additive bwoc with a 15.6 ppg slurry of Texas Lehigh Class A
cement. The fluid loss was found to be 1,175 cubic centimeters.
[0043] Sample Composition No. 3 (comparative) was prepared by
mixing 0.35% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 270 cubic centimeters.
[0044] Sample Composition No. 4 was prepared by mixing 0.7% of a
fluid loss control additive with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss control additive comprised a 1:1 mixture of
HALAD.RTM.-344 and Universal Cement Systems.TM. multi-purpose
cement additive. Accordingly, Sample Composition No. 4 contained
0.35% HALAD.RTM.-344 bwoc and 0.35% Universal Cement Systems.TM.
multi-purpose cement additive bwoc. The fluid loss was found to be
112 cubic centimeters.
[0045] Sample Composition No. 5 (comparative) was prepared by
mixing 0.5% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 80 cubic centimeters.
[0046] A summary of the fluid loss demonstrated by each of the
samples is depicted in Table 1, below.
1 TABLE 1 % Universal FLUID Cement % LOSS FLUID Systems .TM. HALAD
.RTM. -344 (cc) Sample 0 0 1,574 Composition No. 1 Sample 0.5 0
1,175 Composition No. 2 Sample 0 0.35 270 Composition No. 3 Sample
0.35 0.35 112 Composition No. 4 Sample 0 0.5 80 Composition No.
5
[0047] Thus, Example 1 demonstrates, inter alia, that the use of a
fluid loss control additive comprising a reduced dose of an acrylic
acid copolymer derivative delivers performance comparable to a
larger dose of an acrylic acid copolymer derivative.
EXAMPLE 2
[0048] Sample Composition No. 4 was then permitted to age for a
period of two days, and a period of ten days. After each time
period had elapsed, a fluid loss test was again performed for 30
minutes at 1,000 psi and 125.degree. F. After aging for a total of
two days, Sample Composition No. 4 demonstrated a fluid loss of 84
cubic centimeters. After aging for a total of ten days, Sample
Composition No. 4 demonstrated a fluid loss of 76 cubic
centimeters. This Example demonstrates, inter alia, that the use of
a fluid loss control additive comprising a reduced dose of an
acrylic acid copolymer derivative, can deliver performance equal to
or superior to a larger dose of an acrylic acid copolymer
derivative.
EXAMPLE 3
[0049] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0050] Sample Composition No. 6 (comparative) was prepared by
mixing 0.5% of HALAD.RTM.-413 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 615 cubic centimeters.
[0051] Sample Composition No. 7 was prepared by mixing a 15.8 ppg
slurry of an experimental cement bearing compositional similarities
to a Class H cement with 1.0% of a fluid loss control additive
comprising a 1:1 mixture of Universal Cement Systems.TM.
multi-purpose cement additive with HALAD.RTM.-413; accordingly,
Sample Composition No. 7 contained 0.5% HALAD.RTM.-413 bwoc and
0.5% Universal Cement Systems.TM. multi-purpose cement additive
bwoc. The fluid loss was found to be 212 cubic centimeters.
[0052] Sample Composition No. 8 (comparative) was prepared by
mixing 0.7% of HALAD.RTM.-413 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 188 cubic centimeters.
[0053] Sample Composition No. 9 (comparative) was prepared by
mixing 0.5% of HALAD.RTM.-4 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 196 cubic centimeters.
[0054] Sample Composition No. 10 was prepared by mixing a 15.8 ppg
slurry of an experimental cement bearing compositional similarities
to a Class H cement with 1.0% of a fluid loss control additive
comprising a 1:1 mixture of Universal Cement Systems.TM.
multi-purpose cement additive and HALAD.RTM.-4; accordingly, Sample
Composition No. 10 contained 0.5% HALAD.RTM.-4 bwoc and 0.5%
Universal Cement Systems.TM. multi-purpose cement additive bwoc.
The fluid loss was found to be 100 cubic centimeters.
[0055] Sample Composition No. 11 (comparative) was prepared by
mixing 0.7% of HALAD.RTM.-4 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss was found to be 64 cubic centimeters.
[0056] A summary of the fluid loss demonstrated by each of the
samples is depicted in Table 2, below.
2TABLE 2 % Universal FLUID Cement % % LOSS FLUID Systems .TM. HALAD
.RTM. -413 HALAD .RTM. -4 (cc) Sample 0 0.5 0 615 Composition No. 6
Sample 0.5 0.5 0 212 Composition No. 7 Sample 0 0.7 0 188
Composition No. 8 Sample 0 0 0.5 196 Composition No. 9 Sample 0.5 0
0.5 100 Composition No. 10 Sample 0 0 0.7 64 Composition No. 11
[0057] Universal Cement Systems.TM. multi-purpose cement additive
comprises a hydratable polymer and a dispersant. Example 3
demonstrates, inter alia, that the use of an improved fluid loss
control additive comprising a hydratable polymer, a dispersant, and
a reduced dose of an acrylic acid copolymer derivative provides
comparable fluid loss control to a fluid loss control additive
comprising a larger dose of an acrylic acid copolymer derivative.
Inter alia, Example 3 also demonstrates that a variety of an
acrylic acid copolymer derivatives are suitable for combination
with, inter alia, a hydratable polymer and a dispersant, in the
fluid loss control additives of the present invention.
EXAMPLE 4
[0058] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 190.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed per API Specification 10.7 for 30
minutes at 1,000 psi and 205.degree. F.
[0059] Sample Composition No. 12 (comparative) was prepared by
mixing 0.49% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss at 1,000 psi and 205.degree. F. was found to
be 220 cubic centimeters.
[0060] Sample Composition No. 13 was prepared by mixing 0.98% of a
fluid loss control additive of the present invention with a 15.8
ppg slurry of an experimental cement bearing compositional
similarities to a Class H cement. The fluid loss control additive
comprised a 1:1 mixture of Universal Cement Systems.TM.
multi-purpose cement additive and HALAD.RTM.-344; accordingly,
Sample Composition No. 13 contained 0.49% HALAD.RTM.-344 bwoc and
0.49% Universal Cement Systems.TM. multi-purpose cement additive
bwoc. The fluid loss at 1,000 psi and 205.degree. F. was found to
be 60 cubic centimeters.
[0061] Sample Composition No. 14 (comparative) was prepared by
mixing 0.7% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. The fluid loss at 1,000 psi and 205.degree. F. was found to
be 44 cubic centimeters.
[0062] A summary of the fluid loss demonstrated by each of the
samples is depicted in Table 3, below.
3 TABLE 3 % Universal FLUID Cement % LOSS FLUID Systems .TM. HALAD
.RTM. -344 (cc) Sample 0 0.49 220 Composition No. 12 Sample 0.49
0.49 60 Composition No. 13 Sample 0 0.7 44 Composition No. 14
[0063] Thus, Example 4 demonstrates, inter alia, that the use of a
fluid loss control additive comprising a reduced dose of an acrylic
acid copolymer derivative delivers performance comparable to a
larger dose of an acrylic acid copolymer derivative. Additionally,
Example 4 demonstrates that such fluid loss control additive is an
effective fluid loss control additive at elevated temperatures and
pressures.
EXAMPLE 5
[0064] A sample composition was prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. The sample was dry blended, then mixed for 35 seconds at
13,000 rpm in a blender. Next, the sample was conditioned to
400.degree. F. in 60 minutes in a stirring fluid loss cell. After
60 minutes, a fluid loss test was performed through a 325-mesh
screen at 1,000 psi and 400.degree. F. for 30 minutes.
[0065] Sample Composition No. 15 was prepared by mixing 0.84% of a
fluid loss control additive of the present invention with a 15.6
ppg slurry comprising 30% "SSA-1" bwoc, and the balance comprising
an experimental cement bearing compositional similarities to a
Class H cement. SSA-1 is a silica flour additive available from
Halliburton Energy Services, Inc., of Houston, Tex. The fluid loss
control additive comprised a 1:1 mixture of Universal Cement
Systems.TM. multi-purpose cement additive and HALAD.RTM.-344;
accordingly, Sample Composition No. 15 contained 0.42%
HALAD.RTM.-344 bwoc and 0.42% Universal Cement Systems.TM.
multi-purpose cement additive bwoc. The fluid loss at 1,000 psi and
400.degree. F. was found to be 400 cubic centimeters.
[0066] Among other things, Example 5 demonstrates that the fluid
loss control additive of the present invention provides fluid loss
control at elevated temperatures.
EXAMPLE 6
[0067] The transition time of a cement composition may be defined
as the time period starting when the cement composition has
sufficient gel strength to support itself yet cannot prevent influx
of formation fluids, and ending when the cement composition
achieves sufficient gel strength to prevent the influx of such
formation fluids. Experimentally, the transition time may be
approximated by measuring the time period in which the gel strength
of a cement composition progresses from about 100 lb per 100
ft.sup.2 to about 500 lb per 100 ft.sup.2.
[0068] The zero-gel time, which may also be referred to as the
delayed-gel time, refers to the time period starting when the
cement composition is placed in a subterranean formation and ending
when the gel strength of the cement composition progresses to about
100 lb per 100 ft.sup.2, i.e., ending when the cement composition
begins its transition time.
[0069] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 40
minutes to 125.degree. F. in a MiniMac.RTM. at 5,000 psi. Then, a
static gel strength test was performed.
[0070] Sample Composition No. 16 (comparative) was prepared by
mixing 0.7% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of an
experimental cement bearing compositional similarities to a Class H
cement. Sample Composition No. 16 demonstrated a zero gel time of
41 minutes, and a transition time of 17 minutes.
[0071] Sample Composition No. 17 was prepared by mixing 1.0% of a
fluid loss control additive of the present invention with a 15.8
ppg slurry of an experimental cement bearing compositional
similarities to a Class H cement. The fluid loss control additive
comprised a 1:1 mixture of Universal Cement Systems.TM.
multi-purpose cement additive and HALAD.RTM.-344; accordingly,
Sample Composition No. 17 contained 0.5% HALAD.RTM.-344 bwoc and
0.5% Universal Cement Systems.TM. multi-purpose cement additive
bwoc. Sample Composition No. 17 demonstrated a zero gel time of 1
hour 16 minutes and a transition time of 17 minutes.
[0072] A summary of the data from each of the samples is depicted
in Table 4, below.
4TABLE 4 % Universal Zero Gel Transition Cement % Time (hours: Time
FLUID Systems .TM. HALAD .RTM. -344 minutes) (minutes) Sample 0 0.7
0:41 17 Composition No. 16 Sample 0.5 0.5 1:16 17 Composition No.
17
[0073] Thus, Example 6 demonstrates, inter alia, that the use of a
fluid loss control additive comprising a reduced dose of an acrylic
acid copolymer derivative delivers performance comparable to a
larger dose of the acrylic acid copolymer derivative.
EXAMPLE 7
[0074] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0075] Sample Composition No. 18 was prepared by mixing 0.7% of a
fluid loss control additive of the present invention bwoc with a
15.8 ppg slurry of an experimental cement bearing compositional
similarities to a Class H cement. The fluid loss control additive
comprised a 1:1 mixture of Universal Cement Systems.TM.
multi-purpose cement additive with HALAD.RTM.-344; accordingly,
Sample Composition No. 18 contained 0.35% HALAD.RTM.-344 bwoc and
0.35% Universal Cement Systems.TM. multi-purpose cement additive
bwoc. The fluid loss was found to be 80 cubic centimeters.
[0076] Sample Composition No. 19 was prepared by mixing a 15.8 ppg
slurry of an experimental cement bearing compositional similarities
to a Class H cement with 0.7% of a fluid loss control additive
comprising 47.5% HALAD.RTM.-344 by weight, 47.5% Universal Cement
Systems.TM. multi-purpose cement additive by weight, and 5% zeolite
by weight. Accordingly, Sample Composition No. 19 contained 0.3325%
HALAD.RTM.-344 bwoc, 0.3325% Universal Cement Systems.TM.
multi-purpose cement additive bwoc, and 0.035% zeolite bwoc. The
fluid loss was found to be 96 cubic centimeters.
[0077] Thus, Example 7 demonstrates, inter alia, that the use of a
fluid loss control additive of the present invention provides
acceptable fluid loss control.
EXAMPLE 8
[0078] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0079] Sample Composition No. 20 (comparative) comprises a 15.8 ppg
slurry of TXI Class H cement, with no fluid loss control additives.
The fluid loss was found to be 1,529 cubic centimeters.
[0080] Sample Composition No. 21 (comparative) was prepared by
mixing 0.35% of Universal Cement Systems.TM. multi-purpose cement
additive bwoc with a 15.8 ppg slurry of TXI Class H cement. The
fluid loss was found to be 1,343 cubic centimeters.
[0081] Sample Composition No. 22 (comparative) was prepared by
mixing 0.35% of HALAD.RTM.-344 bwoc with a 15.8 ppg slurry of TXI
Class H cement. The fluid loss was found to be 64 cubic
centimeters.
[0082] Sample Composition No. 23 was prepared by mixing 0.35% of
HALAD.RTM.-344 bwoc and 0.0157% of a hydrated polymer (CARBOTRON
20) bwoc with a 15.8 ppg slurry of TXI Class H cement. The fluid
loss was found to be 60 cubic centimeters.
[0083] Sample Composition No. 24 was prepared by mixing 0.35% of
HALAD.RTM.-344 bwoc, 0.0157% of a hydrated polymer (CARBOTRON 20)
bwoc, and 0.204% of a dispersant (CFR-3.TM.) bwoc, with a 15.8 ppg
slurry of TXI Class H cement. The fluid loss was found to be 44
cubic centimeters.
[0084] Sample Composition No. 25 was prepared by mixing a 15.8 ppg
slurry of TXI Class H cement with 0.7% of a fluid loss control
additive comprising 47.5% of HALAD.RTM.-344 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% zeolite by weight. Accordingly, Sample Composition
No. 25 contained 0.3325% HALAD.RTM.-344 bwoc, 0.3325% Universal
Cement Systems.TM. multi-purpose cement additive bwoc, and 0.035%
zeolite bwoc. The fluid loss was found to be 44 cubic
centimeters.
[0085] Sample Composition No. 26 was prepared by mixing 0.35% of
HALAD.RTM.-344 bwoc and 0.204% of a dispersant (CFR-3.TM.) bwoc,
with a 15.8 ppg slurry of TXI Class H cement. The fluid loss was
found to be 48 cubic centimeters.
[0086] A summary of the data from each of the samples is depicted
in Table 5, below.
5TABLE 5 % Universal % FLUID Cement % % CARBOTRON % LOSS FLUID
Systems .TM. HALAD .RTM.-344 Zeolite 20 CFR-3 .TM. (cc) Sample 0 0
0 0 0 1,529 Composition No. 20 Sample 0.35 0 0 0 0 1,343
Composition No. 21 Sample 0 0.35 0 0 0 64 Composition No. 22 Sample
0 0.35 0 0.0157 0 60 Composition No. 23 Sample 0 0.35 0 0.0157
0.204 44 Composition No. 24 Sample 0.3325 0.33250 0.035 0 0 44
Composition No. 25 Sample 0 0.35 0 0 0.204 48 Composition No.
26
[0087] Among other things, Example 8 demonstrates that the addition
of, inter alia, a zeolite, a hydratable polymer, and a dispersant,
to an acrylic acid copolymer derivative provides improved fluid
loss control.
EXAMPLE 9
[0088] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0089] Sample Composition No. 27 (comparative) was prepared by
mixing 0.7% of HALAD.RTM.-413 bwoc with a 16.4 ppg slurry of
Capitol Class H cement. The fluid loss was found to be 44 cubic
centimeters.
[0090] Sample Composition No. 28 (comparative) was prepared by
mixing 0.475% of HALAD.RTM.-413 bwoc with a 16.4 ppg slurry of
Capitol Class H cement. The fluid loss was found to be 115 cubic
centimeters.
[0091] Sample Composition No. 29 was prepared by mixing 1.0% of a
fluid loss control additive of the present invention bwoc with a
16.4 ppg slurry of Capitol Class H cement. The fluid loss control
additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5% Universal
Cement Systems.TM. multi-purpose cement additive by weight, and 5%
zeolite by weight. Accordingly, Sample Composition No. 29 comprises
0.475% HALAD.RTM.-413 bwoc, 0.475% Universal Cement Systems.TM.
multi-purpose cement additive bwoc, and 0.05% zeolite bwoc. The
fluid loss was found to be 60 cubic centimeters.
[0092] Sample Composition No. 30 was prepared by mixing 1.0% of a
fluid loss control additive of the present invention bwoc with a
16.4 ppg slurry of Capitol Class H cement. The fluid loss control
additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5% Universal
Cement Systems.TM. multi-purpose cement additive by weight, and 5%
shale by weight. Accordingly, Sample Composition No. 30 comprises
0.475% HALAD.RTM.-413 bwoc, 0.475% Universal Cement Systems.TM.
multi-purpose cement additive bwoc, and 0.05% shale bwoc. The fluid
loss was found to be 72 cubic centimeters.
[0093] Sample Composition No. 31 was prepared by mixing 1.0% of a
fluid loss control additive bwoc with a 16.4 ppg slurry of Capitol
Class H cement. The fluid loss control additive comprised 47.5%
HALAD.RTM.-413 by weight, 47.5% Universal Cement Systems.TM.
multi-purpose cement additive by weight, and 5% vitrified by
weight. Accordingly, Sample Composition No. 31 comprises 0.475%
HALAD.RTM.-413 bwoc, 0.475% Universal Cement Systems.TM.
multi-purpose cement additive bwoc, and 0.05% vitrified bwoc. The
fluid loss was found to be 62 cubic centimeters.
[0094] A summary of the data from each sample is depicted in Table
6, below.
6TABLE 6 % Universal % FLUID Cement % % % Vitrified LOSS FLUID
Systems .TM. HALAD .RTM.-413 Zeolite Shale Shale (cc) Sample 0 0.7
0 0 0 44 Composition No. 27 Sample 0 0.475 0 0 0 115 Composition
No. 28 Sample 0.475 0.475 0.05 0 0 60 Composition No. 29 Sample
0.475 0.475 0 0.05 0 72 Composition No. 30 Sample 0.475 0.475 0 0
0.05 62 Composition No. 31
[0095] Thus, Example 9 demonstrates, inter alia, that the use of a
fluid loss control additive comprising a reduced dose of an acrylic
acid copolymer derivative delivers performance comparable to a
larger dose of the acrylic acid copolymer derivative.
EXAMPLE 10
[0096] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 180.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
180.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0097] Sample Composition No. 32 (comparative) was prepared by
mixing 2% of HALAD.RTM.-413 bwoc with a 17.7 ppg slurry that
comprised Capitol Class H cement, 35% SSA-1 bwoc, 17.5% sodium
chloride bwoc, 16% of a weighting material bwoc, and 0.25% of a set
retarder (HR.RTM.-5) bwoc. HR.RTM.-5 retarder is a cement set
retarder that is commercially available from Halliburton Energy
Services, Duncan, Okla. The fluid loss was found to be 26 cubic
centimeters.
[0098] Sample Composition No. 33 was prepared by mixing 2% of a
fluid loss control additive of the present invention bwoc with a
17.7 ppg slurry that comprised Capitol Class H cement, 35% SSA-1
bwoc, 37.2% salt by weight of water, 16% of a weighting material
bwoc, and 0.25% of a set retarder (HR.RTM.-5) bwoc. The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% zeolite by weight. Accordingly, Sample Composition
No. 33 comprised 0.95% HALAD.RTM.-413 bwoc, 0.95% Universal Cement
Systems.TM. multi-purpose cement additive bwoc, and 0.1% zeolite
bwoc. The fluid loss was found to be 82 cubic centimeters.
[0099] Sample Composition No. 34 was prepared by mixing 3% of a
fluid loss control additive of the present invention bwoc with a
17.7 ppg slurry that comprised Capitol Class H cement, 35% SSA-1
bwoc, 37.2% salt by weight of water, 16% of a weighting material
bwoc, and 0.25% of a set retarder (HR.RTM.-5) bwoc. The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% zeolite by weight. Accordingly, Sample Composition
No. 34 comprised 1.425% HALAD.RTM.-413 bwoc, 1.425% Universal
Cement Systems.TM. multi-purpose cement additive bwoc, and 0.15%
zeolite bwoc. The fluid loss was found to be 33 cubic
centimeters.
[0100] Sample Composition No. 35 was prepared by mixing 3% of a
fluid loss control additive of the present invention bwoc with a
17.7 ppg slurry that comprised Capitol Class H cement, 35% SSA-1
bwoc, 37.2% salt by weight of water, 16% of a weighting material
bwoc, and 0.25% of a set retarder (HR.RTM.-5) bwoc. The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% shale by weight. Accordingly, Sample Composition No.
35 comprised 1.425% HALAD.RTM.-413 bwoc, 1.425% Universal Cement
Systems.TM. multi-purpose cement additive bwoc, and 0.15% shale
bwoc. The fluid loss was found to be 20 cubic centimeters.
[0101] Sample Composition No. 36 was prepared by mixing 3% of a
fluid loss control additive of the present invention bwoc with a
17.7 ppg slurry that comprised Capitol Class H cement, 35% SSA-1
bwoc, 37.2% salt by weight of water, 16% of a weighting material
bwoc, and 0.25% of a set retarder (HR.RTM.-5) bwoc. The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% vitrified shale by weight. Accordingly, Sample
Composition No. 36 comprised 1.425% HALAD.RTM.-413 bwoc, 1.425%
Universal Cement Systems.TM. multi-purpose cement additive bwoc,
and 0.15% vitrified shale bwoc. The fluid loss was found to be 18
cubic centimeters.
[0102] A summary of the data for each of these samples is provided
below in Table 7.
7TABLE 7 % Universal % FLUID Cement % % % Vitrified LOSS FLUID
Systems .TM. HALAD .RTM.-413 Zeolite Shale Shale (cc) Sample 0 2.0
0 0 0 26 Composition No. 32 Sample 0.95 0.95 0.1 0 0 82 Composition
No. 33 Sample 1.425 1.425 0.15 0 0 33 Composition No. 34 Sample
1.425 1.425 0 0.15 0 20 Composition No. 35 Sample 1.425 1.425 0 0
0.15 18 Composition No. 36
[0103] Among other things, Example 10 demonstrates that the use of
a fluid loss control additive comprising a reduced dose of an
acrylic acid copolymer derivative delivers performance comparable
to a larger dose of the acrylic acid copolymer derivative.
EXAMPLE 11
[0104] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. Next, the sample was conditioned for 20
minutes at 125.degree. F. in an atmospheric consistometer. After
the sample was poured into a preheated cell with a 325 mesh screen,
a fluid loss test was performed for 30 minutes at 1,000 psi and
125.degree. F., in accordance with API RP 10B, Recommended
Practices for Testing Well Cements.
[0105] Sample Composition No. 37 (comparative) was prepared by
mixing 0.6% bwoc of an acrylic acid copolymer derivative with a
16.4 ppg slurry that comprised Lehigh Class H cement. The acrylic
acid copolymer derivative comprised a polymer complex comprising 1
part by weight of a polymer comprising 70 mole % of AMPS, 17 mole %
of N, N-dimethylacrylamide, and 13 mole % of acrylamide, and 2
parts by weight of hydroxyethylcellulose having 1.5 moles of
ethylene oxide substitution. The fluid loss was found to be 242
cubic centimeters.
[0106] Sample Composition No. 38 was prepared by mixing 0.8% of a
fluid loss control additive of the present invention bwoc with a
16.4 ppg slurry that comprised Lehigh Class H cement. The fluid
loss control additive comprised a 1:1 mixture of an acrylic acid
copolymer derivative and Universal Cement Systems.TM. multi-purpose
cement additive. The acrylic acid copolymer derivative comprised a
polymer complex comprising 1 part by weight of a polymer comprising
70 mole % of AMPS, 17 mole % of N, N-dimethylacrylamide, and 13
mole % of acrylamide, and 2 parts by weight of
hydroxyethylcellulose having 1.5 moles of ethylene oxide
substitution. Accordingly, Sample Composition No. 38 comprised 0.4%
of the first acrylic acid copolymer derivative bwoc and 0.4%
Universal Cement Systems.TM. multi-purpose cement additive bwoc.
The fluid loss was found to be 312 cubic centimeters.
[0107] Sample Composition No. 39 (comparative) was prepared by
mixing 0.6% of an acrylic acid copolymer derivative bwoc with a
16.4 ppg slurry that comprised Lehigh Class H cement. The acrylic
acid copolymer derivative comprised first monomers formed from
AMPS, second monomers formed from maleic acid, third monomers
formed from N-vinyl caprolactam, and fourth monomers formed from
4-hydroxybutyl vinyl ether. The fluid loss was found to be 64 cubic
centimeters.
[0108] Sample Composition No. 40 was prepared by mixing 0.8% of a
fluid loss control additive of the present invention bwoc with a
16.4 ppg slurry that comprised Lehigh Class H cement. The fluid
loss control additive comprised a 1:1 mixture of an acrylic acid
copolymer derivative and Universal Cement Systems.TM. multi-purpose
cement additive. The acrylic acid copolymer derivative comprised
first monomers formed from AMPS, second monomers formed from maleic
acid, third monomers formed from N-vinyl caprolactam, and fourth
monomers formed from 4-hydroxybutyl vinyl ether. Accordingly,
Sample Composition No. 38 comprised 0.4% of the acrylic acid
copolymer derivative bwoc and 0.4% Universal Cement Systems.TM.
multi-purpose cement additive bwoc. The fluid loss was found to be
64 cubic centimeters.
[0109] Sample Composition No. 41 (comparative) was prepared by
mixing 0.6% of an acrylic acid copolymer derivative (22% active)
bwoc with a 16.4 ppg slurry that comprised Lehigh Class H cement.
The acrylic acid copolymer derivative comprised a waffle tannin
having monomers formed from AMPS grafted thereto. The fluid loss
was found to be 30 cubic centimeters.
[0110] Sample Composition No. 42 was prepared by mixing 0.8% of a
fluid loss control additive of the present invention bwoc with a
16.4 ppg slurry that comprised Lehigh Class H cement. The fluid
loss control additive comprised a 1:1 mixture of an acrylic acid
copolymer derivative and Universal Cement Systems.TM. multi-purpose
cement additive. The acrylic acid copolymer derivative comprised a
waffle tannin having monomers formed from AMPS grafted thereto.
Accordingly, Sample Composition No. 42 comprised 0.4% the acrylic
acid copolymer derivative bwoc and 0.4% Universal Cement
Systems.TM. multi-purpose cement additive bwoc. The fluid loss was
found to be 28 cubic centimeters.
[0111] A summary of the data for each of these samples is provided
below in Table 8.
8 TABLE 8 % Universal % Acrylic Acid FLUID Cement Copolymer LOSS
FLUID Systems .TM. Derivative (cc) Sample 0 0.6.sup.1 242
Composition No. 37 Sample 0.4 0.4.sup.1 312 Composition No. 38
Sample 0 0.6.sup.2 64 Composition No. 39 Sample 0.4 0.4.sup.2 64
Composition No. 40 Sample 0 0.6.sup.3 30 Composition No. 41 Sample
0.4 0.4.sup.3 28 Composition No. 42 .sup.1The acrylic acid
copolymer derivative comprised a polymer complex comprising 1 part
by weight of a polymer comprising 70 mole % of AMPS, 17 mole % of
N,N-dimethylacrylamide, and 13 mole % of acrylamide, and 2 parts by
weight of hydroxyethylcellulose having 1.5 moles of ethylene oxide
substitution. .sup.2The acrylic acid copolymer derivative comprised
first monomers formed from AMPS, second monomers formed from maleic
acid, third monomers formed from N-vinyl caprolactam, and fourth
monomers formed from 4-hydroxybutyl vinyl ether. .sup.3The acrylic
acid copolymer derivative comprised a waffle tannin having monomers
formed from AMPS grafted thereto.
[0112] Thus, Example 11 demonstrates, among other things, that the
use of a fluid loss control additive comprising a reduced dose of
an acrylic acid copolymer derivative delivers performance
comparable to a larger dose of the acrylic acid copolymer
derivative.
EXAMPLE 12
[0113] Sample compositions were prepared according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. After sample preparation, compressive
strength tests were performed on each of the samples using an
ultrasonic cement analyzer according to API Specification 10A,
Twenty-Third Edition, April 2002. Furthermore, the time for each of
the samples to reach a compressive strength of 50 psi and 500 psi,
respectively, was recorded. Each sample was brought up to
220.degree. F. and 3,000 psi in 60 minutes. Next, the samples were
brought up to 250.degree. F. in 240 minutes while static.
[0114] Sample Composition No. 43 (comparative) was prepared by
mixing 0.5% of HALAD.RTM.-413 bwoc with a 16.9 ppg slurry that
comprised Texas Lehigh Class H cement, 35% SSA-1 bwoc and 0.7% of a
set retarder (HR.RTM.-601). HR-601.RTM. retarder is a set retarder
that is commercially available from Halliburton Energy Services,
Duncan, Okla.
[0115] Sample Composition No. 44 was prepared by mixing 0.73% of a
fluid loss control additive of the present invention bwoc with a
16.9 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc and 0.7% of a set retarder (HR.RTM.-601). The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% zeolite by weight. Accordingly, Sample Composition
No. 44 comprised 0.347% HALAD.RTM.-413 bwoc, 0.347% Universal
Cement Systems.TM. multi-purpose cement additive bwoc, and 0.036%
zeolite bwoc.
[0116] Sample Composition No. 45 was prepared by mixing 0.73% of a
fluid loss control additive of the present invention bwoc with a
16.9 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc and 0.7% of a set retarder (HR.RTM.-601). The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% shale by weight. Accordingly, Sample Composition No.
45 comprised 0.347% HALAD.RTM.-413 bwoc, 0.347% Universal Cement
Systems.TM. multi-purpose cement additive bwoc, and 0.036% shale
bwoc.
[0117] Sample Composition No. 46 was prepared by mixing 0.73% of a
fluid loss control additive of the present invention bwoc with a
16.9 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc and 0.7% of a set retarder (HR.RTM.-601). The fluid loss
control additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5%
Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% vitrified shale by weight. Accordingly, Sample
Composition No. 46 comprised 0.347% HALAD.RTM.-413 bwoc, 0.347%
Universal Cement Systems.TM. multi-purpose cement additive bwoc,
and 0.036% vitrified shale bwoc.
[0118] A summary of the data for each of these samples is provided
below in Table 9.
9 TABLE 9 Time for Time for 50 psi 500 psi 12 Hour 24 Hour
Compressive Compressive Compressive Compressive Strength Strength
Strength Strength at 250.degree. F. at 250.degree. F. at
250.degree. F. at 250.degree. F. (hr:min) (hr:min) (psi) (psi)
Sample 3:45 4:13 2,834 4,309 Composition No. 43 Sample 4:05 4:47
2,926 4,143 Composition No. 44 Sample 5:28 6:02 2,604 4,135
Composition No. 45 Sample 3:32 4:04 3,234 4,653 Composition No.
46
[0119] Thus, Example 12 demonstrates, inter alia, that cement
compositions of the present invention may provide acceptable levels
of compressive strength.
EXAMPLE 13
[0120] Sample compositions were prepared by mixing a cement slurry
with a fluid loss control additive according to the following
procedure. Each sample was dry blended, then mixed for 35 seconds
at 13,000 rpm in a blender. After preparation, the sample was
poured into a stirring fluid cell with a 325 mesh screen and
brought up to 325.degree. F. in about 1.5 hours. Next, a fluid loss
test was performed for 30 minutes at 1,000 psi and 325.degree. F.,
in accordance with API RP 10B, Recommended Practices for Testing
Well Cements.
[0121] Sample Composition No. 47 (comparative) was prepared by
mixing 2% of HALAD.RTM.-413 bwoc with a 18.5 ppg slurry that
comprised Texas Lehigh Class H cement, 35% SSA-1 bwoc, 17.4% Sodium
Chloride bwoc, 32% of a weighting material bwoc, 0.3% of
SUSPEND.TM. HT bwoc, 1% of a set retarder (HR.RTM.-12), and 0.5% of
a set retarder (HR.RTM.-25). HR.RTM.-12 retarder and HR.RTM.-25
retarder are cement set retarders that are commercially available
from Halliburton Energy Services, Duncan, Okla. SUSPEND.TM. HT is a
high temperature suspension agent that is commercially available
from Halliburton Energy Services, Duncan, Okla.
[0122] Sample Composition No. 48 was prepared by mixing 2.92% of a
fluid loss control additive of the present invention bwoc with a
18.5 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc, 17.4% Sodium Chloride bwoc, 32% of a weighting material
bwoc, 0.3% of SUSPEND.TM. HT bwoc, 1% of a set retarder
(HR.RTM.-12), and 0.5% of a set retarder (HR.RTM.-25). The fluid
loss control additive comprised 47.5% of HALAD.RTM.-413 by weight,
47.5% Universal Cement Systems.TM. multi-purpose cement additive by
weight, and 5% zeolite by weight. Accordingly, Sample Composition
No. 48 comprised 1.39% HALAD.RTM.-413 bwoc, 1.39% Universal Cement
Systems.TM. multi-purpose cement additive bwoc, and 0.15% zeolite
bwoc.
[0123] Sample Composition No. 49 was prepared by mixing 2.92% of a
fluid loss control additive of the present invention bwoc with a
18.5 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc, 17.4% Sodium Chloride bwoc, 32% of a weighting material
bwoc, 0.3% SUSPEND.TM. HT bwoc, 1% of a set retarder (HR.RTM.-12),
and 0.5% of a set retarder (HR.RTM.-25). The fluid loss control
additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5% Universal
Cement Systems.TM. multi-purpose cement additive by weight, and 5%
shale by weight. Accordingly, Sample Composition No. 49 comprised
1.39% HALAD.RTM.-413 bwoc, 1.39% Universal Cement Systems.TM.
multi-purpose cement additive bwoc, and 0.15% shale bwoc.
[0124] Sample Composition No. 50 was prepared by mixing 2.92% of a
fluid loss control additive of the present invention bwoc with a
18.5 ppg slurry that comprised Texas Lehigh Class H cement, 35%
SSA-1 bwoc, 17.4% Sodium Chloride bwoc, 32% of a weighting material
bwoc, 0.3% SUSPEND.TM. HT bwoc, 1% of a set retarder (HR.RTM.-12),
and 0.5% of a set retarder (HR.RTM.-25). The fluid loss control
additive comprised 47.5% HALAD.RTM.-413 by weight, 47.5% Universal
Cement Systems.TM. multi-purpose cement additive by weight, and 5%
vitrified shale by weight. Accordingly, Sample Composition No. 50
comprised 1.39% HALAD.RTM.-413 bwoc, 1.39% Universal Cement
Systems.TM. multi-purpose cement additive bwoc, and 0.15% vitrified
shale bwoc.
[0125] A summary of the data for each of these samples is provided
below in Table 10.
10 TABLE 10 % Universal % FLUID Cement % % % Vitrified LOSS Systems
.TM. HALAD .RTM.-413 Zeolite Shale Shale (cc) Sample 0 2 0 0 0 41
Composition No. 47 Sample 1.39 1.39 0.15 0 0 52 Composition No. 48
Sample 1.39 1.39 0 0.15 0 60 Composition No. 49 Sample 1.39 1.39 0
0 0.15 55 Composition No. 50
[0126] Thus, Example 13 demonstrates, among other things, that the
use of a fluid loss control additive comprising a reduced dose of
an acrylic acid copolymer derivative delivers performance
comparable to a larger dose of the acrylic acid copolymer
derivative.
[0127] Therefore, the present invention is well adapted to carry
out the objects and 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.
* * * * *