Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
144 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 2, a water-soluble sulfonate amide copolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR16## in a proportion of 60 wt.% to 80 wt.% of the weight of the copolymer, and ##STR17## in a proportion of 20 wt.% to 40 wt.% of the weight of the copolymer, wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) 0.25 lbs./bbl. to 6 lbs./bbl. of an acrylate polymer of the formula ##STR18## wherein said acrylate polymer has a molecular weight less than 50,000, and wherein the weight ratio of said sulfonate amide copolymer to said acrylate polymer is about 3:1.
Claim 2
Dependent Claim
144 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 2, a water-soluble sulfonate amide copolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR16## in a proportion of 60 wt.% to 80 wt.% of the weight of the copolymer, and ##STR17## in a proportion of 20 wt.% to 40 wt.% of the weight of the copolymer, wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) 0.25 lbs./bbl. to 6 lbs./bbl. of an acrylate polymer of the formula ##STR18## wherein said acrylate polymer has a molecular weight less than 50,000, and wherein the weight ratio of said sulfonate amide copolymer to said acrylate polymer is about 3:1.
Claim 3
Dependent Claim
145 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 2, a water-soluble copolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR19## in a proportion of 60 wt.% to 80 wt.% of the weight of the copolymer, and ##STR20## in a proportion of 20 wt.% to 40 wt.% of the weight of the copolymer, and wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) 0.25 lbs./bbl. to 6 lbs./bbl. of a water-soluble acrylate propylene glycol copolymer of the formula ##STR21## having a molecular weight of less than 50,000, and wherein the weight ratio of said sulfonate amide copolymer to said acrylate propylene glycol copolymer is about 3:1.
Claim 4
Dependent Claim
145 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 2, a water-soluble copolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR19## in a proportion of 60 wt.% to 80 wt.% of the weight of the copolymer, and ##STR20## in a proportion of 20 wt.% to 40 wt.% of the weight of the copolymer, and wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) 0.25 lbs./bbl. to 6 lbs./bbl. of a water-soluble acrylate propylene glycol copolymer of the formula ##STR21## having a molecular weight of less than 50,000, and wherein the weight ratio of said sulfonate amide copolymer to said acrylate propylene glycol copolymer is about 3:1.
Claim 5
Dependent Claim
158 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 1, a water-soluble terpolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR22## in a proportion of 35 wt.% to 70 wt.% of the weight of the terpolymer, ##STR23## in a proportion of 15 wt.% to 35 wt.% of the weight of the terpolymer, and ##STR24## in a proportion of 10 wt.% to 30 wt.% of the terpolymer, wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) from 0.25 lbs./bbl. to 6 lbs./bbl. of a water-soluble acrylate propylene glycol copolymer of the formula ##STR25## having a molecular weight of less than 50,000, and wherein the weight ratio of said sulfonate amide terpolymer to said acrylate propylene glycol copolymer is about 3:1.
Claim 6
Dependent Claim
158 words
A water-based clay drilling fluid containing from 0.25 lbs./bbl. to 6 lbs./bbl. of (A) sulfonate amide polymer 1, a water-soluble terpolymer, having a molecular weight of about 200,000 to 2 million and consisting of a random distribution of units of the formulae ##STR22## in a proportion of 35 wt.% to 70 wt.% of the weight of the terpolymer, ##STR23## in a proportion of 15 wt.% to 35 wt.% of the weight of the terpolymer, and ##STR24## in a proportion of 10 wt.% to 30 wt.% of the terpolymer, wherein R 1 and R 2 are the same or different and each is hydrogen, methyl, or ethyl, and X + is a cation, and (B) from 0.25 lbs./bbl. to 6 lbs./bbl. of a water-soluble acrylate propylene glycol copolymer of the formula ##STR25## having a molecular weight of less than 50,000, and wherein the weight ratio of said sulfonate amide terpolymer to said acrylate propylene glycol copolymer is about 3:1.
Claim 7
Dependent Claim
66 words
In a method of drilling a well wherein a drilling fluid is circulated in the well while drilling at a temperature up to about 220° C., the improvement of employing as said drilling fluid an aqueous clay base drilling fluid having a pH from 8 to 11.5 which contains the composition of any one of claims 1, 2 or 3 as a fluid loss reducing agent.