DEVELOPMENT METHOD OF POWERFUL MULTI-ZONE LOW-PERMEABILITY OIL DEPOSIT Russian patent published in 2020 - IPC E21B43/20 E21B43/26 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil industry and can be used in development of powerful multi-face low-permeability oil deposit with application of horizontal wells, multi-stage hydraulic fracturing of reservoir (MSHFR) and application of water-gas impact. Method involves drilling parallel horizontal wells, performing hydraulic fracturing of the formation, pumping working fluid in the form of a water-gas mixture into wells, extraction of products from production wells. According to the invention, a deposit consisting of three formations matched in the structural plan is selected, the thickness of the non-collector between which does not exceed 10 m, the total oil-saturated thickness of the middle formation is not less than 40 m, and gas content in the oil of the reservoir - not less than 250 m³/t, wells are drilled with a distance between the horizontal shafts in the production of the middle layer in terms of 300–1000 m, horizontal bores are oriented along bisector formed between vector of maximum stress of formation and direction of natural cracks, injection wells are placed near roof of middle bed, producers - near mid sole bed, in all wells multi-stage hydraulic fracturing of the formation (MSHFR) is carried out so that formed cracks in injection wells create hydrodynamic connection with upper formation, and in production wells - with lower reservoir, stages of MSHFR in production and injection wells are arranged in staggered order, after initial withdrawal of formation product and reduction of formation pressure to level not below oil saturation pressure with gas, injection wells of the water-gas mixture are injected into the injection wells, the water for the water-gas mixture preparation is used to use formation and/or waste water from the given deposit, gas is associated petroleum gas also from said deposit, wherein ratio of water and gas in mixture is determined from laboratory analysis results on oil displacement and hydrodynamic simulation with achievement of maximum oil recovery, and volumes of water and gas for pumping are determined from volumes of data of working agents extracted from production wells and/or available for extraction, working agent breakthrough to production wells, 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: invention provides higher oil recovery of powerful multi-face low-permeable oil deposit.

1 cl, 1 dwg