METHOD OF HYDRAULIC FRACTURING OF A RESERVOIR Russian patent published in 2018 - IPC E21B43/267 E21B43/27 C09K8/80 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the petroleum industry and can be used in the hydraulic fracturing of a carbonate formation or a reservoir of high viscosity oil. Method includes perforating the walls of the well in its necessary interval with channels of a depth not less than the extent of the stress concentration zone in the rocks from the wellbore, draining the pipe string into the fracturing zone, sealing the annular space with a packer above the perforation interval, pumping a gel-like fracturing fluid and acid in portions along the tubing string, aging, removal of acid reaction products from the rock, unpacking the packer, and extracting it from the tubing string from the well. According to the invention, a gel-like fracturing fluid is injected with 1 ton of quartz sand with a stepwise increase in the concentration of quartz sand during the injection of the gel-like fracturing fluid. Further, a cyclic injection of the sulfamic acid composition in 4 cycles is performed with an increase in the portion of the injected composition of sulfamic acid by 1.5 m³ with each cycle. At the end of the injection of the last portion of the sulfamic acid composition, CO₂ in the liquid state in a volume of 10 % of the total volume of the sulfamic acid composition. Then, a 2 % aqueous KCl solution is extruded in a volume of 1.1 from the volume of the well. In the process, all components are pumped with a single flow rate, stop the fracturing process, hold for 24 hours, the pressure is gradually depressurized to zero at 5.0 MPa with an exposure time of 10 min, the reaction products of the acid are removed from the rock formation by swabbing, the packer is unpacked and extracted with the tubing string from the well.

EFFECT: technical result is to increase fracture growth during fracturing; increasing the efficiency of the method in carbonate reservoirs and deposits of high-viscosity oil; increasing the productivity of the well in its subsequent operation; preservation of reservoir properties of the bottomhole formation zone; reduction of wear of the equipment used.

1 cl