FIELD: treatment of produced water by heat method from crude oil production unit for attainment of water withdrawal and recirculation level from 80 to 100% with zero disposal. SUBSTANCE: method includes provision of incoming flow of water in recovery of crude oil from formation, heating of water in separator for formation of steam fraction and concentrated liquid fraction containing polluting impurities, compression of steam fraction in compressor for formation of temperature differential in evaporator-heat exchanger, monitoring of temperature differential and temperature in evaporator-heat exchanger, circulation of concentrated liquid fraction through evaporator-heat exchanger and heated separator, condensation of steam fraction and gathering of distillate, formation of high-pressure steam, injection of waste steam from steam turbine into formation, gathering of crude oil and produced water from formation, separation of crude oil and produced water, withdrawal of, at least, one part of concentrated liquid fraction containing polluting impurities. EFFECT: increased efficiency of withdrawal of formation water and its treatment for prevention of scale formation in distillation unit. 9 cl, 17 dwg, 1 tbl
