METHOD OF DEVELOPING OIL POOL Russian patent published in 1996 - IPC

FIELD: oil and gas production. SUBSTANCE: nonuniform oil pool is developed by way of drilling boreholes in row arrangement, withdrawing oil from productive wells, and pumping in working medium through injecting wells in a mode of reducing formation pressure to reaching 80-85% that of initial pressure. Flow lines of pumped in working medium are marked, which are perpendicular to rows of injection wells. Watered productive wells occurring on these flow lines are turned into injecting ones. Development is resumed under conditions of maintaining formation pressure. Then those oil pool zones are chosen that have reduced values of porosity, permeability, oil saturation, exhaustion degree, watering rate, and also increased clay content. Additional productive wells are drilled and placed inside the chosen zone and/or beyond this zone on opposite side from the nearest raw of injection wells. Additional productive wells are shot in confining part of their productive beds. Oil production is carried out under depression not lower than 85% based on initial formation pressure. As working medium, water (for instance, Devonian bed water) with density 1.08-1.10 g/cu.cm is used. Pumping in of working medium is carried out in cyclic mode: 10-20 days pumping, 10-20 days stand on condition of equality of volumes of taken out and pumped in fluid during four months of development. EFFECT: increased oil production. 3 cl