Drilling fluids containing an admixture of polyethoxylated, sulfurized fatty acids and polyalkylene glycols

Claim 2

An aqueous drilling fluid consisting essentially of an aqueous phase containing clay solids dispersed therein by a ferrochrome lignosulfonate and containing an admixture of a water soluble polyethoxylated sulfurized unsaturated fatty acid containing from about 14 to about 18 carbon atoms and wherein the number of ethylene oxide groups therein is on an average of from about 10 to about 12 and wherein the sulfur content is from about 2 to about 6%, by weight, basis ethoxylated fatty acid moiety, and a water soluble polyethylene glycol having an average molecular weight in the range of from about 400 to about 1000, the ratio of said glycol to said polyethoxylated sulfurized fatty acid being from about 2 to about 4 parts by weight per part by weight of said fatty acid, said admixture being present in said drilling fluid in an amount of from about 0.5 to about 5 pounds per barrel and being effective to improve the lubricity of said drilling fluid without impairing its drilling fluid properties.

Claim 3

An aqueous drilling fluid as claimed in claim 1 wherein said admixture is present in said aqueous phase in an amount of from about 1 to 3 pounds per barrel.

Claim 4

An aqueous drilling fluid as claimed in claim 1 wherein said fatty acid is oleic acid.

Claim 5

An aqueous drilling fluid as claimed in claim 3 wherein the sulfur content of said fatty acid varies from about 3 to 5% by weight.

Claim 6

An aqueous drilling fluid as claimed in claim 1 wherein said fatty acid contains an average of about 10 ethylene oxide groups.

Claim 7

An aqueous drilling fluid as claimed in claim 1 wherein said glycol has an average molecular weight of from about 400 to about 600.

Claim 8

An aqueous drilling fluid as claimed in claim 6 wherein said glycol is polyethylene glycol 400.

Claim 9

An aqueous drilling fluid as claimed in claim 6 wherein said glycol is polyethylene glycol 600.

Claim 10

An aqueous drilling fluid as claimed in claim 6 wherein said glycol is polyethylene glycol 1000.

Claim 11

In a method of drilling wells wherein a drilling fluid is circulated in the well in contact with an earth formation during the drilling operation, the improvement which comprises contacting said earth formation with an aqueous drilling fluid consisting essentially of an aqueous phase containing clay solids dispersed therein by a ferrochrome lignosulfonate dispersant and containing an admixture of a water soluble polyethoxylated sulfurized unsaturated fatty acid containing from about 14 to about 18 carbon atoms and wherein the number of ethylene oxide groups therein is on an average of from about 10 to about 12 and wherein the sulfur content is from about 2 to about 6%, by weight, basis ethoxylated fatty acid moiety, and a water soluble polyethylene glycol having an average molecular weight in the range of from about 400 to about 1000, the ratio of said glycol to said polyethoxylated sulfurized fatty acid being from about 2 to 4 parts by weight per part by weight of said fatty acid, said admixture being present in an amount of from about 0.5 to about 5 pounds per barrel and being effective to improve the lubricity of said drilling fluid without impairing its drilling fluid properties.

Claim 12

In a method of drilling wells wherein a drilling fluid is circulated in the well in contact with an earth formation during the drilling operation, the improvement which comprises contacting said earth formation with an aqueous drilling fluid consisting essentially of an aqueous phase containing clay solids dispersed therein by a ferrochrome lignosulfonate dispersant and containing an admixture of a water soluble polyethoxylated sulfurized unsaturated fatty acid containing from about 14 to about 18 carbon atoms and wherein the number of ethylene oxide groups therein is on an average of from about 10 to about 12 and wherein the sulfur content is from about 2 to about 6%, by weight, basis ethoxylated fatty acid moiety, and a water soluble polyethylene glycol having an average molecular weight in the range of from about 400 to about 1000, the ratio of said glycol to said polyethoxylated sulfurized fatty acid being from about 2 to 4 parts by weight per part by weight of said fatty acid, said admixture being present in an amount of from about 0.5 to about 5 pounds per barrel and being effective to improve the lubricity of said drilling fluid without impairing its drilling fluid properties.

Claim 13

A method as claimed in claim 10 wherein said admixture is present in said aqueous phase in an amount of from about 1 to 3 pounds per barrel.

Claim 14

A method as claimed in claim 10 wherein said fatty acid is oleic acid.

Claim 15

A method as claimed in claim 10 wherein the sulfur content of said fatty acid varies from about 3 to 5% by weight.

Claim 16

A method as claimed in claim 10 wherein said fatty acid contains an average of about 10 ethylene oxide groups.

Claim 17

A method as claimed in claim 10, wherein said glycol is a polyethylene glycol having an average molecular weight of from about 400 to about 600.

Claim 18

A method as claimed in claim 15 wherein said glycol is polyethylene glycol 400.

Claim 19

A method as claimed in claim 15 wherein said polyethylene glycol is polyethylene glycol 600.

Claim 20

A method as claimed in claim 10 wherein said glycol is polyethylene glycol 1000.