METHOD FOR LIMITING WATER INFLOW TO PRODUCTIVE BED Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: this can be used for limiting water inflow to productive bed made of dense low-permeable terrigenous rock with deep wells. According to method, injected into drowned well and subsequently pressure-forced into productive bed is plugging agent in the form of 0.5-1% solution of polyacrylamide in brine water and cross-linking agent which contains polyvalent cations. Used as cross-linking agent is 5-10% solution of sulfuric aluminium. Before injection into drowned well of 0.5-1% solution of polyacrylamide, successively injected into well are following materials: 3-15% solution of sodium tripolyphosphate and hydrocarbon-alkaline solution which contains butethal, methanol, 30-40% solution of alkaline metal hydroxide, and hydrocarbon solvent in following ratio of components, mass%: betathol - 1.5-2.5, 30-40% solution of alkaline metal hydroxide - - 0-15, methanol - 1-2, hydrocarbon solvent - the balance. Upon that, pressure in well is increased to 0.5-2,0 MPa and well is kept under pressure during 16-48 h. After pressure-forcing of cross-linking agent into productive bed, well is kept under down-forcing pressure during 8-16 h. Application of aforesaid method allows for creation of preliminary injectivity of well. EFFECT: higher efficiency. 2 cl