Diamond Shamrock Chemicals Company

Diamond Shamrock Chemical

Christopher M Garvey

Arpad Savoly

Albert L Resnick

Thomas M Weatherford

Jose L Villa

An aqueous drilling fluid having present in an amount sufficient to disperse the fluid and to provide resistance to high temperatures and solids contamination of the drilling fluid, at least one salt of a polymer or copolymer of acrylic or methacrylic acid with alkanolamine, alkylamine, mixtures of alkanolamine and alkylamine, mixtures of lithium and alkanolamine, mixtures of lithium and alkylamine and mixtures of lithium, alkanolamine and alkylamine, the polymer having a weight average molecular weight of between about 2,000 and about 15,000 and a pH of from about 6 to about 8.5 and where mixtures of lithium and alkanolamine, lithium and alkylamine or mixtures of lithium, alkanolamine and alkylamine are used, the amount of lithium is present to give from about 30% to about 70% of the desired neutralization of the polymer and the alkanolamine and/or alkylamine is present to give from about 70% to about 30% of the desired neutralization of the polymer.

Drilling fluid dispersant

Drilling fluid compositions and methods of using such compositions in oil, gas and water well drilling fluid operations to reduce fluid loss from the composition to the formation are disclosed. Such compositions incorporate a terpolymer formed from (a) a vinyl containing alkyl or aromatic substituted sulfonate selected from the group consisting of 2-acrylamido, 2-methyl propane sulfonic acid (AMPS), sodium vinyl sulfonate or vinyl benzene sulfonate, and method salts thereof at about 10 to 75 weight percent in the polymer; (b) an unsaturated polybasic acid such as itaconic acid at about 1 to 60 weight percent; and metal salts thereof and (c) a nonionic monomer selected from the group consisting of acrylamide, N, N-dimethylacrylamide, N-vinyl pyrrolidone, N-vinyl acetamide, or dimethylamino ethyl methacrylate and metal salts thereof at about 10 to 76 weight percent. The terpolymer should have a molecular weight between 200,000 to 1,000,000. The preferred terpolymer comprises AMPS, acrylamide and itaconic acid. The polymers are used as fluid loss control additives for aqueous drilling fluids and are particularly advantageous when used with lime or gypsum based drilling muds containing soluble calcium ions.

Fluid loss control additives and drilling fluids containing same

Cementing compositions and methods of using such compositions in oil, gas and water well cementing operations to reduce fluid loss from the composition to the formation are disclosed. Such compositions incorporate a terpolymer formed from (a) an acid monomer selected from the group consisting of 2-acrylamido, 2-methyl propane sulfonic acid (AMPS), sodium vinyl sulfonate or vinyl benzene sulfonate, and metal salts thereof at about 10 to 75 weight percent in the polymer; (b) an unsaturated polybasic acid such as itaconic acid at about 1 to 60 weight percent; and metal salts thereof and (c) a nonionic monomer selected from the group consisting of acrylamide, N, N dimethylacrylamide, N-vinyl pyrrolidone, N-vinyl acetamide, or dimethylamino ethyl methacrylate and metal salts thereof at about 10 to 76 weight percent. The terpolymer should have a molecular weight between 200,000 to 1,000,000. The preferred terpolymer comprise AMPS, acrylamide and itaconic acid. The polymer is used as a fluid loss agent in oil well cementing in conjunction with dispersants, like naphthalene sulfonate formaldehyde condensate alkali salt, a polymer of ketone aldehyde sulfonate alkali salt, or lignosulfonate. At the same time, all of the above can be used in freshwater to saturated NaCl or seawater cement slurries where HEC fluid loss additive does not work.

Growing community of inventors

Princeton, NJ, United States of America

Christopher M Garvey