METHOD FOR DEVELOPMENT OF OIL DEPOSIT AT LATE STAGE OF DEVELOPMENT Russian patent published in 2016 - IPC E21B43/20 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry and, in particular, to development of oil deposit at late stage of development. Method comprises determining remaining oil reserves in interwell space. For this purpose, method includes selecting flooded oil deposit, from which are selected ≥ 80 % of extracted oil reserves and oil-saturated strata ≥2 m. Based on results of geophysical investigations of wells and laboratory analysis of core, selecting zones with low-producing rocks, opened by adjacent wells. Drainage area in production wells is determined to determine boundaries of zone with residual profitable oil reserves in interwell space. In direction of said zones of adjacent production wells with least development of reserves, additional production side and lateral horizontal shafts are drilled. Length of side and horizontal shafts does not exceed distance between adjacent wells. In presence in section of adjacent wells of more than one oil-filled formation, in each of which there is a zone with residual profitable oil reserves, side shaft is drilled with exposure of all said zones. Displacement agent is injected through injection wells. Product is extracted through production wells.

EFFECT: technical result is higher efficiency of development due to uniform coverage of formation by water flooding and reduction of costs.

1 cl, 2 dwg, 1 ex