Drilling fluid composition and process for the filtrate reduction of drilling fluid compositions containing mixed metal hydroxides

摘要

PCT No. PCT/EP92/02920 Sec. 371 Date Nov. 12, 1993 Sec. 102(e) Date Nov. 12, 1993 PCT Filed Dec. 16, 1992 PCT Pub. No. WO93/12194 PCT Pub. Date Jun. 24, 1993.In order to reduce the filtrate of aqueous drilling fluid compositions based on clay minerals containing mixed metal hydroxides, a polysaccharide that is partially etherified with hydroxyethyl and/or hydroxypropyl groups is used as the filtrate-reducing agent.