METHOD FOR PREPARATION OF DOWNHOLE EQUIPMENT FOR REPAIR AND/OR RECOVERY OPERATIONS ON WELL UNDER PRESSURE Russian patent published in 2025 - IPC E21B19/00 

FIELD: obtaining oil and gas from wells.

SUBSTANCE: invention relates to oil and gas industry. Method for preparation of downhole equipment for repair and/or recovery operations on a well under pressure consists in the fact that a blowout preventer (BOP) unit is installed at the wellhead and installing a repair tower with a hydraulic jack unit and a telescopic mast mounted thereon. First, the repair tower is assembled, for which four steel support posts are connected to each other by three support plates: lower, middle and upper. On the lower support plate, a stationary wedge grip is pre-mounted, by means of which in the process of repair and/or recovery works through the adapter the weight of the pipe string or tubing string or drill pipes is transferred to the lower support plate, and lower platform for mounting/dismantling of upper annular preventer of BOP unit, and besides, the lower part of the telescopic mast is fixed on the lower platform, an inverted stationary wedge grip is mounted on the middle support plate to hold the buoyancy force of the existing pipe string, or tubing, or drill pipes on the support posts of the repair tower, on the upper support plate, an upper working platform is mounted, a telescopic mast is attached to the upper support plate and four hydraulic cylinders of the hydraulic jack are mounted on the upper support plate, on rods of which a movable support plate is fixed with possibility of its replacement with a support plate with a rotor, on which a movable wedge grip is fixed from above and an inverted movable wedge grip is fixed from below. Prior to installation of repair tower and BOP unit and performance of well repair and/or well recovery under pressure, wellhead of which is equipped with a casing head, a tubing head and a production tree, the latter is prepared by sealing the in-tube space of downhole equipment with the help of bridge plugs, which are lowered into the well and installed on a geophysical cable, for which the wellhead equipment is equipped with a hydraulic wellhead lubricator to perform the above operation for lowering into the well under pressure of bridge plugs, and after confirmation of tightness of intra-tube space of downhole equipment with installed bridge plug, wellhead hydraulic lubricator and X-mas tree are dismantled, after which on the pipe head the BOP unit is mounted or on the pipe head a full-bore gate valve is installed, on which the BOP unit is mounted, and then above described repair tower is installed on BOP unit. Hydraulic cylinders are connected to a power unit installed next to the well for supplying liquid under pressure to them via high-pressure hydraulic hoses, and at the lower platform, the hydraulic lines are connected to the hydraulic distribution unit and serviced, and thus a hydraulic unit is formed for repair and/or recovery of the well, and then, using the main and auxiliary winches of the telescopic mast, to the upper working platform lifted are the single tubing string, drill pipes and elements of downhole tool and equipment, they are assembled at the upper working site and lowered into the well by means of a hydraulic jack unit using pipes, downhole equipment and tool for gripping, which are fixed on movable support plate by means of fixed on it wedge grips. At the upper working platform, by means of a hydraulic pipe wrench, which is pre-suspended on a beam mounted on said platform, make-up or unscrewing of tubing pipes, drill pipes and elements of downhole tool and equipment is performed, and by means of the control panel installed on the above platform, operations are performed to control operation of hydraulic cylinders, main and auxiliary winches, wedge grippers, rotor, hydraulic valves of the BOP unit and preventers of the BOP unit and thus, round-trip operations are carried out and a complex of works on current repair of a well or overhaul of a well is performed, and/or on recovery of a well.

EFFECT: possibility of carrying out practically all types of repair and/or recovery works at the well under pressure without killing it.

2 cl, 2 dwg