METHOD FOR DEVELOPMENT OF OIL FORMATIONS OF DIFFERENT PERMEABILITY SEPARATED BY IMPERVIOUS ROCKS Russian patent published in 1995 - IPC

FIELD: oil producing industry. SUBSTANCE: wells are arranged to expose both formations according to design pattern of highly permeable formation. Additional producing wells are drilled between producing and injection wells. Water is injected to more permeable formation from the beginning of development, and at the same time, oil is recovered from all wells which have exposed less permeable formation, and also from more permeable formation from producing wells which have exposed both formations up to drop of pressure in less permeable formation equal to sum of bottom- hole pressure in highly permeable formation and pressure built up by fluid column characterized by the difference in elevations of formation occurrence. Water is started to be injected to less permeable formation exposed by injection wells. Formed in producing wells which have exposed both formations are accumulating caverns. Bottom-hole pressure is raised in less permeable formation up to formation pressure by regulating recovery of fluid from combined producing wells, and, simultaneously, oil is recovered from more permeable formation. Then, cycle is repeated. EFFECT: increased recovery of oil from less permeable formations and accelerated extraction of reserves. 1 dwg