FIELD: drilling of wells.
SUBSTANCE: invention relates to heat-resistant polymer compositions of scale formation inhibitors and their use. Method of treating fresh water or a salt solution used in an oil, gas or geothermal production well or subterranean formation, for scale formation inhibition, comprising a step of introducing an aqueous composition for inhibiting scale formation into an oil, gas or geothermal production well or into a subterranean formation, wherein said aqueous composition contains a copolymer of carboxylic acids containing the following monomers: i) two or more monoethylenically unsaturated acids and/or anhydrides thereof and/or one of their salts and ii) styrene sulphonic acid and/or one of its salts, in which i) two or more monoethylenically unsaturated acids and/or anhydrides thereof and/or one of their salts are a) acrylic acid and b) methacrylic acid and ii) styrene sulphonic acid and/or one of its salts is 4-styrene sulphonic acid, and in which ia) acrylic acid is present in amount of 50 to 70 wt %, ib) methacrylic acid is present in amount of 25 to 25 wt % and ii) styrenesulphonic acid and/or one of its salts is present in amount of 15 to 25 wt %, wherein WT % is expressed relative to total weight of polymerised monomers.
EFFECT: technical result is high heat resistance at high-pressure/high-temperature applications and in salt solutions with high concentration of calcium.
6 cl, 5 tbl, 2 ex
