INTENSIFICATION METHOD FOR WELL OPERATION Russian patent published in 2020 - IPC E21B43/267 

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. According to the method, a productive formation is perforated by opening and a through packer is installed above the penetrated stratum. Hydrodynamic investigations are used to determine a colmataged zone. 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, gradient of fracture. For test hydraulic fracturing of bed (HF) test pumping is performed with 20/40 mesh fraction of proppant with volume of proppant of not less than 1.5 ton with length of cracks forming, 25 % larger than colmataged zone. Preliminary analysis of service water, testing of gelling agent on solubility in water and structure formation, adding to the gelling agent in the water a clay stabilizer, a demulsifier and a decomposition regulator, forming a liquid of basic HF. Rheological parameters of cross-linked system of linear gel and water are calculated, fracturing fluid is tested for complete destruction of gel, preliminary studies also include testing physical and chemical properties of water for preparation of fracturing fluid, at which the water mineralization should not exceed 320 mlg/l, the volume and composition of the fluid of the main hydraulic fracturing of the formation is determined, which ensures the efficiency of hydraulic fracturing of the formation with thickness of 0.8 m and more. Volume and pressure of injection at main HF are corrected proceeding from actually obtained results during test pumping. Carry out a download obtained with test liquid HF crack basic with the addition of liquid HF destructor directly into a stream with a concentration of at least 1.2 l/m³, with final concentration of proppant is not less than 600 kg/m³ and not more than 1,200 kg/m³. Note here that destruction of undecomposed destructor gel is avoided.

EFFECT: disclosed method widens field of use for formations with any thickness and increases efficiency of HF due to increased conductivity of obtained cracks and inflow of well fluid due to preliminary HF, providing formation of cracks beyond colmataged zone of formation, and use of liquid destructor, which is added to fracturing fluid immediately before pumping into well.

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