DEVICE AND METHOD FOR MULTI-STAGE HYDRAULIC FRACTURING (MSHF) PER ONE ROUND-TRIP OPERATION Russian patent published in 2020 - IPC E21B43/267 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a method and devices for oil production, and can be used for multi-stage hydraulic fracturing of a formation (MSHF) in a production well. Device consists of tubing string on which upper selective packer with through hole is mounted from top to bottom, bottom selective packer with through hole, cutoff pressure valve, piercing device perforating casing string in intervals of planned hydraulic fracturing, and between upper and lower packers in tubing string is installed fraction port, under which there is a perforated branch pipe of the tubing string. Proposed method comprises perforation in well bed interval and fracturing by fluid pumping via tubing string. At that perforation of intervals of assumed stages of hydraulic fracturing and fracturing in perforation intervals is performed in one lowering-lifting by realization of following stages: lowering of the proposed device for the MSHF to the well, adjustment of the piercing device to the lower interval of the hydraulic fracturing, at that, pumping of the liquid through the tubing string, which, coming from the hole above the perforated branch pipe, activates the upper and lower selective packers. Actuation of piercing device and perforation of casing string. Pressure drop in the tubing string before the packers transition to the transport position and movement of the declared device for the MSHF to the position, where inter-packer space of device is located at level of perforated interval of hydraulic fracturing. Activation of upper and lower selective packers. Activation of shut-off pressure valve. Hydraulic fracturing is performed by pumping fluid along the tubing string in this perforated formation interval. Pressure drop in the tubing string before the packers transition to the transport position.

EFFECT: technical result consists in reduction of time spent on performance of MSHF in multilayer wells, and increasing efficiency of action on separate formations due to perforation of intervals of presumed stages of MSHF and MSHF itself per one round-trip operation with application of piercing perforation.

2 cl, 1 dwg