OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2015 - IPC E21B43/20 E21B43/38 

FIELD: oil and gas industry.

SUBSTANCE: method involves lowering to a shaft of a production well below a liquid level of a pipe string with pumps, as well as with filters installed on pipe ends, recovery of the product from the lower productive formation, separation of oil and water in the well shaft, water pumping to the upper formation, and oil lifting to the surface. Into the well there lowered are two filters below the upper formation, each on an individual pipe string. Filters represent pipes with capillary holes with a diameter of not more than 2 mm and density of at least 50 holes per metre. With that, one filter on the pipe string has a hydrophobic surface with a degree of hydrophobic properties of at least 99%, and the other filter on the other pipe string has a hydrophilic surface with a degree of hydrophilic properties of at least 99%. The upper formation is cut off from above and from below with packers so that no liquid can flow via an annular space from the lower formation to the upper formation, and the pipe string with a filter with a hydrophilic surface is perforated opposite the upper formation. Liquid is filtered through the capillary holes of the filters, thus being separated into oil and water.

EFFECT: reduction of water flooding of the recovered product and increase of oil recovery of a productive formation.

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