Additives for oil-based drilling muds and compositions containing such additives

摘要

A novel ammonium salt of quebracho prepared by reacting quebracho with alkyl quaternary ammonium salts is an effective fluid loss control agent when used in oil base drilling fluids for use in drilling oil and gas wells, especially in water in oil emulsion drilling mud formulations, controlling filtrate loss of the oil-base mud under high temperature and high pressure conditions.