METHOD OF OIL RECOVERY AT LATE STAGES OF OIL DEPOSIT DEVELOPMENT AND DEVICE ITS EMBODIMENT Russian patent published in 2001 - IPC

FIELD: oil producing industry; applicable in operation of oil fields with considerable rate of water encroachment of formations. SUBSTANCE: method includes perforation of casing in oil saturated and water zones of formation; setting of packer in casing at level of water-oil contact; injection of a part of well fluid into formation water zone from formation oil-saturated zone to form fringe from water-oil emulsion which screens water in region of perforation of formation water zone. Device for the method embodiment has a body and packer connected with tubings. The body accommodates two plungers, suction and pressure valves. The first plunger with pressure valve is connected with sucker rod string. Fixed pressure valve is located in device lower part. Located between them on side of fixed valve is movable the second plunger with suction valves in upper and lower parts of plunger. Made in middle part of the second plunger is bore hole over diameter with length not smaller than the second plunger stroke and holes in region of bore hole to pass well fluid. Located higher than the second plunger is limiter of its stroke. EFFECT: higher oil recovery from formation. 2 cl, 1 dwg