DEVELOPMENT METHOD OF WATER-FLOODED OIL DEPOSIT Russian patent published in 2013 - IPC E21B43/00 E21B43/32 

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of a deposit with production wells crossing the formation with water-saturated and oil-saturated zones separated with a non-permeable natural interlayer, lowering of a casing string with further formation perforation, investigation of its water-oil saturation and their deposit intervals, dimensions of non-permeable natural interlayer, creation of a screen from an insulating compound, which separates water-saturated zone of the formation from oil-saturated zone, cutting of some part of the casing string, enlarging the well shaft at that interval; filling of the enlarged interval of the well shaft with insulating compound, drilling of insulating compound in the well so that the screen remains opposite to oil-saturated zone of the formation after waiting period of the insulating compound curing, perforation opposite to oil-saturated zone of the formation, and development of the well. At arrangement of non-permeable natural interlayer below oil-saturated zone of formation and thickness of non-permeable natural interlayer over 8 m at the bottom interval of non-permeable natural interlayer there installed is a blind packer, and temporary clogging of oil-saturated zone of formation is performed. Some part of the casing string is cut out to 1.0-1.5 m at height of 1.0 m above bottom of non-permeable natural interlayer, and in casing string interval at height 1.0-1.5 m below roof of non-permeable natural interlayer there made are holes across the casing string. Cementing casing string is lowered to well with through drillable packer, packer is installed in casing string opposite to non-permeable natural interlayer in interval between cut out part and holes in casing string, circulation of fresh water is induced on well head along cementing casing string under packer via casing string annulus and intertube space on well head by pumping of fresh water. If there is no fresh water circulation, impulse treatment of non-permeable natural interlayer by mud acid composition is performed. When circulation is available pumping of fresh water is stopped, then insulating compound is pumped via grout casing string and is forced into casing string annulus in interval of non-permeable natural interlayer with formation of insulating bridge in inner space of casing string to the bottom of oil-saturated zone of the formation. Then grout casing string is lifted above the bottom of oil-saturated zone of the formation and surpluses of synthetic resin are washed out from intertube space of casing string. After some period required for synthetic resin curing through and blind packers are drilled as well as insulating bridge, temporary clogging of formation is removed and well is brought into operation.

EFFECT: improving efficiency of the method owing to excluding behind-the-casing flow in the well between water- and oil-saturated zones of the formation and possibility of their simultaneous-separate development.

2 ex, 5 dwg