METHOD FOR MULTIPLE HYDRAULIC FRACTURING OF FORMATION IN HORIZONTAL SHAFT OF WELL Russian patent published in 2018 - IPC E21B43/267 E21B43/114 E21B34/10 

FIELD: mining.

SUBSTANCE: invention relates to methods of hydraulic fracturing in a horizontal borehole. Method includes drilling a horizontal wellbore, determining oil-saturated reservoir intervals, opened by a horizontal trunk of a well, running in hole and fastening of a shank, interval execution of a group of perforations with the help of a hydro-sandblast perforator, performing hydraulic fracturing of the formation to form branched cracks, followed by fixing the fracture with proppant and removing the proppant from the horizontal wellbore. During the process of running the shank into the horizontal wellbore, it is equipped with a coupling ring made of a drilled material, after fixing the shank in a horizontal wellbore, a bottom-up arrangement is assembled at the wellhead at the wellhead at the lower end of the pipe string, comprising a check valve extending from the face to the mouth, a perforator, a by-pass valve, and then the tubing string is run into the horizontal wellbore at the nearest interval from the bottomhole of the oil-saturated formation. During the running process, the pipe string is provided with sealing bushings, the number of which corresponds to the number of oil-saturated intervals of the formation. Through the nozzles of a hydraulic perforator, a group of perforations in the liner is executed in front of the oil-saturated interval of the formation. Then, by backwashing, the spent liquid-sand mixture is washed from the horizontal wellbore, further, the column of pipes is moved downward and a by-pass valve is installed in the middle of the oil-saturated interval of the formation, in front of a group of perforations, with the sealing sleeve entering the sleeve ring. Drop the junk element into the pipe string, create hydraulic pressure in the pipe string, with the bypass valve bushing displacing the spring, opening the radial holes of the bypass valve and, without relieving injection pressures, perform hydraulic fracturing and then fix the cracks. After the proppant cracks are fixed in the oil-saturated reservoir interval, the proppant is removed from the horizontal wellbore, further, the column of pipes is moved up to the next oil-saturated interval of the formation and the operations described above are repeated, starting with the execution of a group of perforations in the liner and ending with the removal of proppant from the horizontal wellbore, after completion of multiple fracturing, the column of piping with the arrangement is removed from the horizontal wellbore.

EFFECT: technical result is increased reliability of the method implementation; reduced labor intensity and duration of work; increased efficiency of proppant washout from the horizontal wellbore; simplified design of equipment in the implementation of the method.

1 cl, 4 dwg