OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2014 - IPC E21B43/20 E21B33/12 

FIELD: oil and gas industry.

SUBSTANCE: according to the method direction of reservoir-scale fractures is determined, development elements are formed by drilling of horizontal injection wells as per square grid pattern with parallel placement of boreholes and producing downhole splitters with rounded bottomhole ending which are placed around the borehole of each horizontal well. Pumping of working agent is done through injection wells and recovery of products through multi-hole producing wells. When the latter are water flooded water-flooding intervals are identified and isolated. According to the invention a downhole splitter is made in the semi-ellipse shape which major axis is directed at the angle of 30-60° towards direction of fractures while ratio of the minor semi-axis of the ellipse b/2 towards major semi-axis a/2 is equal to 0.1-0.8. At that boreholes of a downhole splitter have length of (0.6-0.8)·a each in productive part of the stratum and water-swellable packers are installed at them at each 50-250m. The boreholes are placed near the roof of the productive stratum at distance of 0.5 m at least and less than 2 m from the roof. The horizontal injection well is placed in plane along the ellipse major axis of a producing downhole splitter with length of (0,3-0,6)·a of its horizontal part in the productive stratum, at water-oil contact or the bottom of oil-filled formation in profile at distance of 0.2 m at least and less than 1m from it.

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

2 cl, 4 ex, 3 dwg