METHOD FOR SELECTIVE ISOLATION OF HIGH-PERMEABLE INTERVALS IN OIL BED Russian patent published in 1999 - IPC

FIELD: oil production industry. SUBSTANCE: method relates to methods for isolation of high-permeable intervals of oil bed in injection and producing wells. According to method for selective isolation of high-permeable intervals in bed, injected into well is suspension of water-soluble polymer with cross-linking agent in hydrocarbon liquid. Also injected is buffer portion of water in amount of 100-150% of volume of inert liquid. In addition, injected is solution of polyhexamethyleneguamidine (metacide) in concentration of 0.5-1.0 mas.%. Volume of portion of metacide solution is calculated basing from fact, that amount of metacide as to dry product constitutes 10-20% of amount of polymer with subsequent pushing-down of composition by water in amount of not less than 100% of initial volume of inert liquid. Usable in function of water-soluble polymer are polyacrylamide, carboxylmethylcellulose and other materials. Usable as polymer cross-linking agent are reagent containing cations of polyvalent metals. Application of method allows for producing in high-permeable intervals of oil bed of strong bed of water-isolating material which retains its isolating properties for long period of time, thus prolonging isolating action. EFFECT: higher efficiency. 4 tbl