METHOD FOR KILLING AND/OR DECOMMISSIONING INJECTION WELL FOR REPAIR Russian patent published in 2025 - IPC E21B43/12 E21B43/16 

FIELD: obtaining oil and gas from wells.

SUBSTANCE: invention relates to the oil and gas industry and can be used in killing and decommissioning injection wells, as well as emptying the lifting string in emergency situations. Method for killing and/or decommissioning an injection well for repair includes lowering a pipe string with a packer into the well, installing a packer above the well perforation section, connection of pipe string with injection valves with formation of closed annular space, supply of liquid to well through pipe string to maintain formation pressure, further termination of liquid supply to the formation, emptying of liquid from the well with provision of pressure reduction at the wellhead, pumping into the well of a weighted liquid having a density higher than that of the well liquid, with provision of pressure at the bottom of the well above the formation pressure, opening in the lower part of the pipe string above the packer with subsequent supply of the weighted liquid to the well with emptying of the well fluid from the annular space – outside the pipe string. Prior to lowering, the pipe string above and below the packer is equipped with at least three knock-down valves spaced apart along the height and arranged uniformly along the perimeter in a projection from above, and from below – with a cone diverter diverging from top to bottom. Opening of the pipe string before pumping the weighted liquid is carried out from above and below the packer by dumping from the mouth of the load, which destroys the beaten-out valves for connecting the space inside the pipe string and the annular space, pumping of the weighted liquid, wherein the well fluid is emptied from the annular space after opening the pipe string, followed by temporary holding for the well fluid replacement under the packer through the holes of the beating valves to the weighted fluid due to gravity sedimentation, then, weighted fluid is pumped into the well to ensure pressure at the well bottom above the formation pressure with subsequent extraction of the pipe string.

EFFECT: proposed method for killing and/or decommissioning injection well for repair allows reducing probability of emergency situations due to exclusion of pipe string opening operations and replacement of residual well fluid in annular space between the bottom of the pipe string and under the packer with a killing fluid – a weighted fluid.

2 cl, 2 dwg