METHOD OF ISOLATION OF INTAKE FORMATIONS IN WELL Russian patent published in 2003 - IPC

FIELD: oil production, particularly, methods of isolation of intake formations in well; applicable, in elimination of intake zones in repair of producing and injection wells with low formation pressure, in control of injectivity profile of injection wells and shutoff of water inflows to oil producing wells. SUBSTANCE: method includes simultaneous-separate injection into formation water-encroached part of organic additive and hydrochloric acid solution in form of two flows. Organic additive is used in form of product based on saponified still bottoms from production of fat acids, containing, at least, 30% of solid residue, at least, 1.7 mg-equiv./l of sodium soaps of synthetic fat acids and not in excess of 0.1% of free alkali in terms of solid residue. Aqueous solution of hydrochloric acid is of 5-10% concentration For best method realization, said organic additive is used in form of aqueous solution of 10-15% concentration. Technical result of invention consists in increase of isolation degree of intensive absorption zones, higher plugging-back ability of formed isolating material due to instantaneous formation of homogeneous thick lumpy sediment formed in contact of injected components with high mobility capable of motion in flow of fluid to absorption zone with formation of plugging effect and also due to high adhesive ability of surface layer of that sediment to formation rock, resistant to effect of formation waters and formation temperatures up to plus 80C. EFFECT: higher efficiency of claimed method. 2 cl, 1 tbl