OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2014 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: direction of reservoir-scale fractures is determined, the formation is drilled by vertical and/or inclined wells and downhole splitters as per square grid pattern and five-spot system is formed with drilling in the centre and corners of the system elements by vertical and/or inclined wells and drilling between the central and corner wells in the development pattern of downhole producing splitter with rounded borehole ending, and working fluid injection through injection wells and product recovery through producing wells. If producing wells are flooded the water-flooding interval is identified and water-flooded intervals are isolated. According to the invention, before drilling of the formation sections with total oil-filled thickness of more than 6 m are determined in carbonate reservoirs and/or sections with net oil thickness of 2 m at least in oil zone and at least 4 m in water-oil zone in terrigenous reservoirs. At these sections before drilling of downhole producing splitter direction of reservoir-scale fractures is specified. The downhole splitter is made with semi-ellipse shape which major axis is directed at angle of 30-60° to direction of reservoir-scale fractures with ratio of minor semi-axis to the major semi-axis equal to 0.1-0.8. At that boreholes of producing downhole splitters are made ascending with minimum distance in the lower part up to water-oil contact of 4 m for carbonate reservoirs and 2 m for terrigenous reservoirs and in the upper part with minimum distance of 1 m up to the roof of productive strata.

EFFECT: improving coverage of the productive stratum by development and increasing its production rate.

2 cl, 3 ex, 3 dwg