METHOD FOR PREPARING REAGENT FOR MUD TREATMENT Russian patent published in 2003 - IPC

FIELD: petroleum and gas industry. SUBSTANCE: invention relates to production of chemical reagents used in treatment of mud. Method involves interaction of lignosulfonate containing 0-7.5 mas. p. of iron with acrylic acid, methylacrylate, acrylonitrile as a modifying agent in an aqueous medium, at heating to temperature 97-100 C by grafted radical copolymerization of lignosulfonate and modifying agent in the presence of an initiating agent of reaction, cooling reaction mass to temperature 25 C followed by drying up to preparing dry substance. Lignosulfonate and modifying agent are blown-out with argon preliminary. Mass ratio of lignosulfonate to modifying agent is from 10:10 to 10:0.5 and amount of initiating agent is 0.15-2.8 mas. p. Invention allows the improvement of filtration properties of mud and to reduce nominal viscosity value of this solution simultaneously. EFFECT: improved preparing method. 2 cl, 1 tbl, 21 ex