LUBRICATING ADDITIVE FOR CLAYEY DRILLING FLUIDS AND METHOD OF PREPARATION THEREOF Russian patent published in 1999 - IPC

FIELD: oil and gas production. SUBSTANCE: additive contains 97-99% of sodium salts of high-molecular carboxylic acids and 1-3% of special additive based on mixture of zinc dialkylphenyldithiophosphate with barium alkylphenolates or on barium dialkylphenyldithiophosphate or on their mixture. Preparation of additive consists in neutralizing raw material containing high-molecular carboxylic acids with 10-15% alcoholic solution of sodium hydroxide at 65-85 C and weight ratio of raw material to alkali solution (1.56-2,56): 1 in presence of above-indicated special additive. Raw material can be still residues from synthetic fatty acid production. EFFECT: improved antiwear, lubricating, and antifriction characteristics of additive. 4 cl, 1 tbl, 10 ex