METHOD OF STRONG ROCKS HYDRAULIC FRACTURING AND COMBINED FACILITY FOR DRILLING AND HYDRAULIC FRACTURING OF STRONG ROCK Russian patent published in 2017 - IPC E21B43/26 

FIELD: mining.

SUBSTANCE: method comprises well drilling, subsequent cutting of an initiating slit on its side surface, sealing the well region with the initiating slit and pumping working fluid into the sealed space under high pressure before hydraulic fracturing. These operations are performed with a combined facility for drilling and hydraulic fracturing of strong rocks comprising a housing consisting of a cup with a longitudinal window and a cutting element attached to the piston located inside the cup with the possibility of axial movement, while an adjustable back pressure valve is installed in the piston cavity. The housing is provided with a sleeve rigidly connected to the open part of the cup, and the bottom of the cup is equipped with a drill bit. A sealing element connected to the hydraulic cylinder is installed on the outer surface of the sleeve for sealing the well region with the initiating slit, and the piston has a rod with a valve located thereon and a stroke limiter. The valve is installed with the possibility to interact with the slide valve installed in the sleeve cavity to supply working fluid to the hydraulic cylinder through the holes in the sleeve.

EFFECT: reducing the amount of equipment and the implementation timeframe of the method via reducing the number of operations for installation and dismantling of the well drilling equipment, cutting initiating slits, sealing wells and hydraulic fracturing.

2 cl, 2 dwg