OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2012 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of injection and production wells, pumping of displacement agent (water or water-gas mixture) through injection wells having vertical design, perforation intervals of which are in the deposit below current position of oil-water contact, and product extraction through production wells having vertical and/or horizontal designs and arranged in elevated deposit sections the perforation intervals of which are located at near-roof deposit interval. At water content of extracted products below economically profitable value in oil deposit containing an interlayer of poorly permeable rocks, from vertical injection wells, at deposit bottom there drilled is horizontal shaft or multi-hole branched directed shafts so that they can be arranged under working faces of production wells. As displacement agent pumped to injection wells there used is free gas of hydrocarbon type with content of methane homologues of 25% and higher. At that, pumping of free gas is performed at temperature of 20-40°C and at gas pumping bottomhole pressure that is by 20% lower than saturation pressure. Using recurrent selection of product samples from production wells there determined is value of gas factor and chemical analysis of gas, and when gas breakthrough of separate production wells is defined, sampling of products from them is reduced by 50%. At repeated gas breakthrough to those production wells the gas pumping to injection well from which the gas is supplied to those production wells is stopped and pumping of design volume of viscous liquid is performed. After that, pumping of free hydrocarbon gas to that injection well is restored.

EFFECT: increasing the method's efficiency owing to enlarging the coverage of deposit with displacement agent.

2 dwg