DEVELOPMENT METHOD OF POWERFUL LOW-PERMEABILITY OIL DEPOSIT Russian patent published in 2020 - IPC E21B43/20 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil industry and can be used in development of powerful low-permeability oil deposit using vertical cracks of multi-stage hydraulic fracturing of formation (MSHF) and using gas-lift method of operation. Method for development of powerful low-permeable oil deposit includes drilling on deposit of horizontal wells - HW, cementing of horizontal shafts between casing string and header, secondary opening of reservoir, performance of multi-stage hydraulic fracturing of formation - MSHF, use of packers for separation of horizontal shafts into sections, extraction of products from HW. Reservoir is selected consisting of two formations matched in structural plan, wherein upper formation is purely oil-saturated, and lower one has water-oil contact, or is also purely oil-saturated, total thickness of nonreservoir between formations does not exceed 20 m, total oil-saturated thickness of upper productive formation is not less than 30 m, lower - not less than 20 m, It characterized by oil reservoir gas content of not less than 300 m³/t. HW is drilled at bottom of upper productive formation with distance between horizontal shafts 500–1500 m in plan, horizontal boreholes are arranged parallel to each other and oriented along a bisector formed between a vector of maximum stress of the formation and direction of natural cracks. All HW are made by producers. In all HW, the MSHF is carried out so that the formed cracks create a hydrodynamic connection between the upper and lower productive formations. After withdrawal of formation product and formation pressure drop to the value at which the liquid flow rate of the fluid is reduced by no more than four times from the initial value, the well in which the given yield drop occurred is transferred to the gas lift mode of operation, wherein said gas is represented by produced oil gas from said deposit. Said operations are carried out in all HW deposits, water breakthrough from water-bearing area of lower bed to HW, as well as prevention of reduction of formation pressure below pressure of oil saturation with gas are controlled by modes and operating time of all wells of the deposit.

EFFECT: technical result consists in improvement of oil recovery of powerful low-permeability oil deposit.

1 cl, 1 dwg