METHOD FOR EXTRACTION OF CARBONATE MULTI-BED OIL DEPOSIT OF VOID-CRUMBLING POROSITY Russian patent published in 2006 - IPC E21B43/20 

FIELD: oil industry, namely, technology for extraction of multi-bed oil deposits, in particular, for extraction of carbonate multi-bed oil deposit of void-crumbling porosity.

SUBSTANCE: method includes drilling of product and force wells as a grid, extraction of beds, starting from lower bed until exhaustion, and then - upper bed, draining oil through product wells and forcing liquids into bed through force wells. In accordance to invention, extraction of lower bed is performed firstly in natural mode, draining oil simultaneously through force wells too until bed pressure along force wells decreases to 3-4 MPa with following utilization of force wells for forcing in water. Force wells of upper bed are used for extraction of oil when liquid forcing pressure at lower bed reaches value, sufficient for capillary saturation of carbonate massif channels and for compensation of accumulated oil recovered from bed at zone of selected extraction element. Recovery of oil via force wells of upper bed is performed until bed pressure decreases to value of starting pressure gradient between extraction zone and water-producing area. After that force wells are used for forcing of liquid, while product wells are used for recovery of oil from bed when forcing pressure reaches required value, same as in case of extraction of lower bed.

EFFECT: increased efficiency of extraction of deposit of hydrocarbons due to decreased number of product wells and efficient positioning of force wells.

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