METHOD OF HYDRAULIC FRACTURING OF FORMATION AND INCREASE OF ROCK PERMEABILITY AND EQUIPMENT FOR METHOD EMBODIMENT (VERSIONS)

摘要

FIELD: mining, oil and gas producing industry; applicable in mineral mining through wells after performance of formation hydraulic fracturing and increase of rock permeability in macrovolumes in well zone. SUBSTANCE: method includes drilling of well to preset depth; testing of formation for product inflow; location of pumping unit at well head for supply of working agent to well; tailing-in mineral formation; stimulation by shock waves with help of hydraulic percussive device with transmission of shock waves through fluid waveguide in well with subsequent turning of wave from reflector to formation. Made additionally on well walls, within thickness of formation, are upper and lower circular and rectilinear stress concentrators with help of preliminarily lowered into well cutting tool. Then, lowered into well in assembly with drill string is control valve device with system of radial and longitudinal channels, bushing, spring-loaded valve and straddle packer designed for isolation of one of circular stress concentrators from atop and from its bottom. Lowered into well in composition with tubing are sub with system of radial and longitudinal channels with spring- loaded bushing, hydraulic percussive device, booster pump, high-pressure receiver with controlled pressure-relief valve - high-pressure generator-power hydraulic cylinder with pressure switch. Hydraulic percussive device is put in operation with help of surface pumping unit. After attaining the required value of working agent pressure in intrapacker spaces, its value is increased with help of hydraulic percussive device and surface pumping unit to shift down upper string-loaded two-diameter piston and fixing of its position inside fixed distance switch. Pressure in intrapacker spaces is closed and channel to isolated circular stress concentrator is opened. Pressure boosting in said concentrator from high-pressure receiver is made similarly with help of hydraulic percussive device and surface pumping unit until occurrence of formation hydraulic fracture. Pressure of working agent in region of circular stress concentrator is reduced more than inside packers. Formation hydraulic fracturing is detected by sharp pressure drop when working agent is injected by surface pumping unit. After formation hydraulic fracturing, retainers of upper spring-loaded two-diameter piston of pressure fixed distance switch are released by pressure supplied to lower edge of lower spring-loaded two-diameter of piston-unfastener and by pressure relief in infrapacker spaces, and they are communicated with under-packer and above-packer spaces. After that, device assumes its initial position, and it is moved along well so that packers isolate by their sealing members the other circular stress concentrator, and all operations with it are performed similar to those with the first stress concentrator. Then, device is removed to surface, and device provided with two pairs of packers is lowered for simultaneous isolation of upper and lower circular stress concentrators and performance of hydraulic fracturing along rectilinear stress concentrators on well walls. After hydraulic fracturing along rectilinear stress concentrators, zone of rock weakening on well walls is expanded in macrovolumes and permeability is increased with elimination of plugged pores by cyclic hydraulic pulse stimulation with help of working agent pressure. Vertical fractures do not extend beyond boundaries of fractures in horizontal plane. EFFECT: provided limiting of zone covered by wave stimulation within preset limits of formation thickness. 6 cl, 23 dwg