REAGENT FOR TREATING HIGH-MINERALIZED DRILLING MUD Russian patent published in 2003 - IPC

FIELD: well drilling. SUBSTANCE: reagent is prepared by modifying carboxymethylcellulose through mixing the latter with alkali and epichlorohydrin (modifying agent), carboxymethylcellulose being preliminarily prepared esterification of mercerized cellulose with sodium monochloroacetate in water-organic liquid composed of 45-65% benzene and toluene, 30-50% ethanol and isopropyl alcohol, and 4-5% water. Carboxymethylcellulose is modified in the same reactor and in the same medium and reagent is then separated from reaction mixture using centrifuge or filter-press. EFFECT: increased content of main substance (80-90%) and achieved technologically suitable polymerization degrees, not superior to 700, and substitution degree not superior to 80. 2 tbl