DEVELOPMENT METHOD OF WATER-FLOODED OIL DEPOSIT Russian patent published in 2013 - IPC 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 opposites oil-saturated zone of the formation after waiting period of the insulating compound hardening, perforation opposite oil-saturated zone of the formation, and development of the well. At arrangement of water-saturated zone below oil-saturated zone of the formation and thickness of non-permeable natural interlayer of 0.5 to 4 m at the bottom interval of non-permeable natural interlayer there installed is a blind packer; some part of the casing string is cut out from the blind packer to the roof of the formation oil-saturated zone; the well shaft is expanded at the interval of the cutout part; the expanded well shaft interval is filled with insulating compound. Microcement is used as the above insulating compound so that an insulating bridge is obtained. After waiting period of microcement hardening, the insulating bridge and the blind packer are drilled so that the screen remains opposite non-permeable natural interlayer and oil-saturated zone of the formation with the diameter equal to inner diameter of the casing string; water-saturated formation zone is cutout by placing in the casing string below the cut-out part of a stationary packer with a perforated shank with a limit stop on the working face from below and a sealing joint from above. After that, the cut-out section of the casing string is fixed in the well by lowering an additional string with its installation opposite the cut-out section of the casing string and tight fixation of upper and lower ends of the additional string in the casing string above and below the cut-out section in the well. When oil-saturated zone of the formation is being introduced to the development, drilling perforation of an additional string is performed opposite oil-saturated zone of the formation. During development of water-flooded oil deposit, periodic operation of oil-saturated and water-saturated formation zones is performed.

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.

6 dwg