FORMATION METHOD OF VERTICALLY DIRECTED FRACTURE AT HYDRAULIC FRACTURING OF PRODUCTIVE FORMATION Russian patent published in 2014 - IPC E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: two side horizontal shafts are drilled in a productive formation parallel to each other and arranged in one vertical plane. After perforation is completed, a well strainer is installed in the upper horizontal shaft and a perforated liner is installed in the lower one. Then, oilwell tubing with a packer is lowered to the main shaft of the well, and the above packer is installed between upper and lower horizontal shafts. Before hydraulic fracturing of the productive formation is performed, annular space of the well is equipped on the head with an adjustable throttle and sealed. Moment of fracture formation between upper and lower horizontal shafts is determined as per stepwise rise of pressure in the annular space of the well. After the fracture is formed, pressure in the annular space of the well is reduced by means of the adjustable throttle. Further pumping of carrying liquid with a propping agent and displacement fluid is performed at counter pressure created on the head. After the displacement fluid is pumped, the following is performed in series: unloading of the well, removal of the packer and flushing of the main shaft of the well. Size of cells of the well strainer shall be less than average diametre of particles of the propping agent used at hydraulic fracturing of the productive formation.

EFFECT: improving effectiveness of the hydraulic fracturing process of the productive formation and creating the conditions allowing to reduce carryover intensity of solid mechanical impurities from the productive formation to the well shaft.

6 cl, 1 dwg