COMPOUND FOR ISOLATION OF FORMATION FLUSHED ZONES Russian patent published in 1996 - IPC

FIELD: oil producing industry. SUBSTANCE: compound for isolation of formation flushed zones has the following qualitative and quantitative composition, mas. %: lignosulfonate 5.0-20.0; bichromate of alkali metal 0.5-5.0; water-soluble salts of alkali metals and/or alkali-earth metals 9.0-24.0; mineral acid 0.005-0.5; the balance, water. Compound provides for efficient and long-term isolation in low-permeable reservoirs with the use of secondary material resources (lignosulfonates). EFFECT: higher efficiency of isolation of formation due to increased viscosity of compound with simultaneous preservation of structural and rheological properties of protective shield in time. 2 tbl