FIELD: physico-chemical emulsion-suspension compositions for selective isolation of lost circulation zones and shutoff of formation waters in oil and gas wells; applicable in oil and gas industry in isolation-reconditioning operations in well overhauls. SUBSTANCE: composition includes wastes of oil treatment process and organic solvent with additional nonionic surfactant. Waste of oil treatment process is used in the form of oil sludge cake thinned on press-filter. Organic solvent is used in the form of mixture of nefras AR 120/200 with density of 870 kg/cu.m and mixture of halogen derivatives of hydrocarbons - composition APK with density of 1550 kg/cu.m with the following ratio, wt.%: nonionic surfactant, 7.5-25.0; oil sludge cake thinned on press-filters, 25.0-50.0; organic solvent, the balance. Density of organic solvent is equal to that of fresh and mineralized water phase used for preparation from composition of aqueous emulsion-suspension system, and solvent concentration when introduced into aqueous phase for formation of aqueous emulsion-suspension system varies within 0.1-5.0 wt.%. Method of preparation of claimed composition consists in preliminary dissolving with stirring of nonionic surfactant in organic solvent. Density of organic solvent equals density of fresh and mineralized water phase used for preparation from said composition of aqueous emulsion-suspension system and organic solvent concentration when introduced into water phase for formation of aqueous emulsion suspension system, varies within 0.1-5.0 wt.%. EFFECT: production of sedimentation-stable finely dispersed emulsion-suspension system capable of self-formation in fresh and mineralized water and featuring effect of water shutoff of the most permeable sections of formation. 6 cl, 1 tbl
