METHOD FOR PREPARING ACRYLIC LIGNOSULFONATE REAGENT FOR DRILLING FLUID TREATMENT Russian patent published in 2023 - IPC C09K8/35 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, namely the production of chemicals for the treatment of drilling fluids. A method for preparing an acrylic lignosulfonate reagent for treating drilling fluids includes the interaction of lignosulfonate with an acrylic series modifying agent in an aqueous medium with preliminary blowing of the mass with argon during heating by radical graft copolymerization of the lignosulfonate and modifying agent in the presence of a reaction initiator, cooling the mass to 25°C, followed by drying to obtain dry matter. Modification is carried out at a temperature of 65-85°C. As a modifying agent of the acrylic series, maleic anhydride is used at a mass ratio of lignosulfonate and maleic anhydride of 10:6.8-10:1.36, and hydroperite is used as the reaction initiator in an amount of 0.4-3.2 wt.pts.

EFFECT: improving the quality of the acrylic lignosulfonate drilling fluid treatment agent by simultaneously enhancing its effect on the filtration, rheological and inhibitory properties of the drilling fluid.

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