A copolymer of acrylamide and K salt of acrylic acid was obtained by radical polymn., dried, crushed to about 1 mm granulation and then added to water (4.5-10 g/L) sep. or together with a biopolymer or bentonite. Technol. parameters of the fluids were detd. 15 min and 24 hr after mixing the components. The increase of copolymer concn. resulted in an increase in the rheol. properties of the fluids and in decrease in the filtration efficiency. The addn. of biopolymer and bentonite resulted in increasing the gel strength and plastic viscosity of the fluids, resp.