METHOD FOR EXPLOITATION LAYERED OIL STRATA INHOMOGENEOUS IN PERMEABILITY Russian patent published in 1996 - IPC

FIELD: oil production. SUBSTANCE: first oil is produced under natural operation at the expense of elastic strata stock. After decreasing stratum pressure to the preset minimum level, oil production is stopped and hydrodynamic lamination of the strata begins in abandoned oil wells by flooding productive portions of their shafts by slightly-filtering liquid, for example, clay mortar to the level that is higher a little than productive interval. Water, produced oil etc. may be used as buffer liquid to flood the well above the level of slightly filtering liquid up to the well mouth. Then displacing agent (water, gas etc.) is pumped in the strata, until elastic strata stock is restored up to the primary level. Cycles of oil extraction from the strata and pumping displacing agent in the strata are repeated many times during all the period of well development. Then agent pumping is stopped and oil extraction is kept until strata pressure is decreased to the level of benefit oil production. EFFECT: higher oil production. 2 dwg