METHOD OF INTENSIFICATION OF WELL OPERATION AFTER ITS CONSTRUCTION Russian patent published in 2020 - IPC E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used after completion of the main cycle of well construction with intensification of well operation, formation of cracks and splits in productive formation. Method includes secondary opening of walls of well in interval of formation of well, lowering of production string of pump-compressor pipes with packer, installation of packer above roof of perforated productive formation including pumping of hydraulic fracturing of formation (HFF) into sub-packer area of pump-compressor pipes, creation of HFF pressure in sub-packer zone and HFF fluid injection into formed cracks, and re-acid HFF. After secondary opening of walls of the well with the help of hydrodynamic studies, a colmataged zone formed by particles of rocks is determined, cement solution and products of oxidative reaction of perforated charges, and analysis of core solubility involves determining composition of acid composition for hydraulic fracturing of formation, determining time of closure of crack, efficiency of fracturing fluid, fracture gradient, well pressure with well head pressure of not more than 60 MPa is performed. Based on the research data download performed acid composition with HCl concentration below 15 %, with an initial flow rate of at least 0.4 m³/min, injection of deflecting agent carried in specific volume of at least 1 m³ per long meter of the effective thickness of the reservoir at a rate of at least 0.5 m³/min with a viscosity less than 600 cP in a volume allowing formation cracks permit passage with a radius greater than the radius colmatage zone at least than by 20 %. After process conditioning for stabilization of cracks after primary HFF repeated HFF by pumping of fracturing fluid on water basis containing in composition acid composition with concentration of HCl of not less than 15 %, with flow rate of not less than 1 m³/min with bottom-hole pressure not higher than rupture pressure of roof and/or formation bottom, after initiation of formation rupture and development of crack, injection of deflecting agent with flow rate of not less than 1 m³/min is performed. Further, acid composition is vacuumed to the formation with upgraded process fluid in volume of not less than one volume of tubing string and sub-packer space; well is stopped with pressure reduction down to reservoir pressure.

EFFECT: proposed method of intensification of well operation after its construction allows to increase efficiency of HFF especially in low-permeability deposits.

4 cl