Oil field cementing methods and compositions

Claim 1

A cementing composition for use in cementing operations for oil and gas wells having bottom hole circulating temperatures above about 200° F. comprising a salt water cement slurry, a water soluble form of borate, and a terpolymer, wherein said terpolymer is comprised of about 10-65 mole precent of a strong acid monomer selected from the group consisting of sodium vinylsulfonate, 2-acrylamido, 2-methyl propane sulfonic acid, and vinyl benzene sulfonic acid; about 10-60 mole percent of a weak acid monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid and vinyl acetic acid; and about 10-60 mole percent of a nonionic monomer selected from the group consisting of acrylamide, N-vinylpyrrolidone and N,N dimethylacrylamide; wherein the average molecular weight of said terpolymer is between about 10,000 and about 100,000.

Claim 13

A method of cementing a conduit in a borehole penetrating an earthen formation having a bottom hole circulating temperature above about 200° F. by introducing a cementing composition into the space between said conduit and said formation and allowing said composition to set wherein said cementing composition is comprised of a salt water, cement slurry, a water-soluble form of borate in an amount of from about 0.1% to about 3% by weight of cement, and from about 0.1% to about 3% by weight of cement of a terpolymer, wherein said terpolymer is comprised of from about 10-65 mole percent of a strong acid monomer selected from the group consisting of sodium vinylsulfonate, 2-acrylamido, 2-methyl propane sulfonic acid, and vinyl benzene sulfonic acid; about 10-60 mole percent of a weak acid monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid and vinyl acetic acid; and about 10-60 mole percent of a nonionic monomer selected from the group consisting of acrylamide, N-vinylpyrrolidone and N,N dimethylacrylamide; wherein the average molecular weight of said terpolymer is between about 10,000 and about 100,000.

Claim 14

A method of cementing a conduit in a borehole penetrating an earthen formation having a bottom hole circulating temperature above about 200° F. by introducing a cementing composition into the space between said conduit and said formation and allowing said composition to set wherein said cementing composition is comprised of a salt water, cement slurry, a water-soluble form of borate in an amount of from about 0.1% to about 3% by weight of cement, and from about 0.1% to about 3% by weight of cement of a terpolymer, wherein said terpolymer is comprised of from about 10-65 mole percent of a strong acid monomer selected from the group consisting of sodium vinylsulfonate, 2-acrylamido, 2-methyl propane sulfonic acid, and vinyl benzene sulfonic acid; about 10-60 mole percent of a weak acid monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid and vinyl acetic acid; and about 10-60 mole percent of a nonionic monomer selected from the group consisting of acrylamide, N-vinylpyrrolidone and N,N dimethylacrylamide; wherein the average molecular weight of said terpolymer is between about 10,000 and about 100,000.

Claim 19

A method of cementing a conduit in a borehole penetrating an earthen formation having a bottom hole circulating temperature above about 200° F. by introducing a cementing composition into the space between said conduit and said formation and allowing said composition to set wherein said cementing composition is comprised of a fresh water cement slurry, a water-soluble form of borate in an amount of from about 0.1% to about 3% by weight of cement, and from about 0.1% to about 3% by weight of cement of a terpolymer, wherein said terpolymer is comprised of from about 10-65 mole percent of a strong acid monomer selected from the group consisting of sodium vinylsulfonate, 2-acrylamido, 2-methyl propane sulfonic acid, and vinyl benzene sulfonic acid; about 10-60 mole percent of a weak acid monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid and vinyl acetic acid; and about 10-60 mole percent of a nonionic monomer selected from the group consisting of acrylamide, N-vinylpyrrolidone and N,N dimethylacrylamide; wherein the average molecular weight of said terpolymer is between about 10,000 and about 100,000.

Claim 20

A method of cementing a conduit in a borehole penetrating an earthen formation having a bottom hole circulating temperature above about 200° F. by introducing a cementing composition into the space between said conduit and said formation and allowing said composition to set wherein said cementing composition is comprised of a fresh water cement slurry, a water-soluble form of borate in an amount of from about 0.1% to about 3% by weight of cement, and from about 0.1% to about 3% by weight of cement of a terpolymer, wherein said terpolymer is comprised of from about 10-65 mole percent of a strong acid monomer selected from the group consisting of sodium vinylsulfonate, 2-acrylamido, 2-methyl propane sulfonic acid, and vinyl benzene sulfonic acid; about 10-60 mole percent of a weak acid monomer selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid and vinyl acetic acid; and about 10-60 mole percent of a nonionic monomer selected from the group consisting of acrylamide, N-vinylpyrrolidone and N,N dimethylacrylamide; wherein the average molecular weight of said terpolymer is between about 10,000 and about 100,000.