METHOD FOR REPEATED MULTISTAGE HYDRAULIC FRACTURING IN A WELL WITH A HORIZONTAL TAILING-IN USING A CASING STRING OF A SMALLER DIAMETER Russian patent published in 2022 - IPC E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry for the implementation of interval multistage hydraulic fracturing in wells with horizontal tailing-in. In a cemented shank with a diameter of 114.3 mm or 127 mm, a suspension of a non-cemented shank is lowered on the trigger mounting hydraulic or mechanical tool of the transport column, a finishing arrangement consisting of, from bottom to top: a casing shoe with a check valve, an activation coupling: a circulation valve, a hydraulic coupling, a casing string with a non-coupling threaded connection with a diameter of 73 mm with a diameter of the cemented shank of 114.3 mm or 89 mm with a diameter of the cemented shank of 127 mm, a rigid or roller centralizer, a column swelling or hydromechanical packer, a suspension of a non-cemented shank activated mechanically or hydraulically. The suspension of the non-cemented shank is activated mechanically or hydraulically in an operational column with a diameter of 178 mm. Next, the running tool on the transport column is lifted to the surface. After activating the suspension of the non-cemented shank, on a flow string with a diameter of 73 mm or 89 mm, the stinger is lowered and docked with an adapter that is part of the suspension of the non-cemented shank. A frac valve is installed at the mouth for hydraulic fracturing, in order to obtain a connection with the reservoir, in order to create injectivity and the ability to pump the equipment in the future, a hydraulic coupling is activated by creating a pressure of 12 MPa (120 atm) in the flow string. After activation of the hydraulic coupling, communication with the cemented shank is established through the circulation windows in the non-cemented shank, and communication with the formation is established through perforation intervals. Perforation before the first stage of hydraulic fracturing is carried out by descending through the flow string on a geophysical cable or on a flexible flow string to the required depth of the layout. The perforator is activated hydraulically when descending by the flexible flow string or electrically when descending on a cable. Through the formed perforations in the non-cemented shank and in the cemented shank, the hydraulic fracturing stage is performed by pumping hydraulic fracturing gel with proppant through the flow string. Operations to separate the upcoming and previous stages and perforation before the second and subsequent stages of hydraulic fracturing are carried out by lowering the layout through the flow string on a geophysical cable or on the flexible flow string to the required depth. Through the formed perforations in the non-cemented shank and in the cemented shank, the hydraulic fracturing stage is performed by pumping hydraulic fracturing gel with proppant through the flow string. At the same time, the installed packer plug separates the conducted stage from the previous stage of hydraulic fracturing. The subsequent stages of hydraulic fracturing are carried out similarly to the required number of stages along the entire length of the horizontal section of the well.

EFFECT: increase in the productivity of the well.

1 cl, 44 dwg