METHOD OF IMPROVING DEVELOPMENT EFFICIENCY OF LOW-PERMEABILITY OIL DEPOSITS Russian patent published in 2019 - IPC E21B43/26 E21B43/18 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used in development of low-permeable non-uniform oil deposits by horizontal wells (HW) with multistage hydraulic fracturing of formation (MSHFF). Proposed method comprises drilling of horizontal wells with extraction of core in productive stratum, laboratory analysis of core, along horizontal wellbore, depending on formation characteristics, performing interval injection of chemical reagents and multiple hydraulic fracturing of formation. According to the invention, a formation with average permeability of not more than 1 mD is selected, horizontal wellbores are made with length of not less than 1,000 m and arranged in parallel at distance of 200–600 m, core and/or slurry are taken along the entire length of horizontal boreholes with pitch of 10–50 m, horizontal boreholes are cemented using laboratory data of collected core and/or slurry, sampling data and geophysical survey data during drilling, constructing petrophysical, geomechanical and geological-hydrodynamic models, based on which perforation intervals are determined along horizontal shafts, wherein the intervals are separated by packers and perforated such that the productivity of each interval is not more than 10 %, after reducing formation pressure in the well collection zone to 1.0–1.1 of the oil saturation pressure, each second horizontal well is changed for gas injection.

EFFECT: higher oil recovery of oil deposits of low-permeability.

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