METHOD OF WELL PREPARATION FOR HYDRAULIC FRACTURING OF RESERVOIR IN OIL AND GAS WELLS Russian patent published in 2021 - IPC E21B43/26 E21B43/117 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the development of oil and gas fields with horizontal and inclined wells, it can be used to prepare oil and gas wells for hydraulic fracturing of reservoir – HFR for the implementation of interval multi-stage HFR. According to the method, a cumulative perforator is lowered into the well. Perforation is performed in the inclined or horizontal sections of the production column, the cement ring space and the rock of the productive reservoir. Packer plugs are installed in the inclined or horizontal sections of the production column. Previously, reference pipes are installed in the well shank in every 50-75 m, or a packer suspension of the shank is used as a reference point. Before launching into the well, the equipment that is launched into the well is assembled to prepare the well for hydraulic fracturing of reservoir – HFR. The assembly includes a packer plug, a landing chamber, and sections of a cumulative perforator from one to six cases connected in series from the bottom to the top. These sections include a transfer connector with an electric detonator, a load section, a magnetic coupling locator, and a cable tip for connecting to a load-bearing geophysical cable. Before launching the above-mentioned equipment assembly, the well is templated. The connection of the cable tip with the load-bearing geophysical cable is carried out. Through the lubricator installed at the wellhead, the above-mentioned equipment assembly is launched into the well on a load-bearing geophysical cable. On the vertical section of the well, the launch is made under its own weight. The movement of the assembly is tracked on the locator of the couplings relatively to the reference pipes. After entering the inclined or horizontal section, a pump is turned on to supply the process fluid with a flow rate of 0.5 to 1.8 m³/min. The equipment assembly is positioned in the planned interval and the landing chamber for installing the packer plug is activated, then the equipment assembly is disconnected from the packer plug and the equipment assembly is lifted at least 2 meters from the installed packer plug. Perforation of the well is performed by initiating a cumulative perforator. If there are more than one cumulative perforators, then the layout is moved to each subsequent planned interval of perforation. The cumulative perforators are sequentially initiated. Upon completion of the well perforation, the spent equipment assembly is lifted into the lubricator. The root valve of the fountain reinforcement is closed and the spent assembly of the equipment is removed from the lubricator. Before the start of HFR, the ball is discharged into the well. Then the root valve is closed for cutting off the lubricator and the ball is pumped with a liquid flow rate of 0.8 to 2.0 m³/min before landing of the packer plug in the seat. The well is considered ready for HFR.

EFFECT: proposed is well preparation for hydraulic fracturing of reservoir.

1 cl, 6 dwg