Safe deblocking releasing well completion pipe string and operation technology thereof

Abstract

The invention relates to a safe deblocking releasing well completion pipe string and an operation technology thereof, and belongs to the technical field of well completion pipe strings for layered water injection and oil and gas production measures in oil fields. The pipe string is formed by assembling an unpacker, a pipe string stabilizer, packers and other tools, the unpacker comprises an upperjoint, a jacket, a spring ring, a piston, a start pin, a lock ring, a center tube and a lower joint, and when the unpacker is located at the upper end of a first-stage packer in a tool string formed by assembling the pipe string stabilizer, the packers and the other tools, the function of releasing can be achieved; when the unpacker is located between two packers in the tool string, the purpose ofstep-by-step deblocking can be achieved, the success rate of deblocking and unfreezing is improved, and even if the deblocking fails due to complex conditions such as downhole scaling, sand production and casing deformation, the purpose of pulling out an upper pipe string in a releasing mode can be successfully achieved through the unpacker. According to the pipe string, the possibility of overhauling oil and water wells due to the failure of deblocking and unfreezing through dual functions of the unpacker is greatly reduced.

Description

technical field [0001] The invention relates to a well completion pipe string for safely unblocking and discarding hands and an operation process thereof, and belongs to the technical field of well completion pipe strings for layered water injection and oil and gas recovery measures in oilfields. Background technique [0002] With the deepening of oil and gas development, there are more and more measures such as multi-stage staged acid fracturing, layered production and fine water injection. These measures require multi-stage packers to be connected in series to form a multi-stage layered process string. For the stability of the process string, it is often necessary to add a string stabilizer with an anchor function; If it is too large, it will fail to unblock and eventually lead to overhaul. [0003] In order to solve this problem, some technicians use pull-off safety joints or unsealing tools to solve the problem that the multi-stage layered string cannot be pulled out, b...

AI Technical Summary

Problems solved by technology

[0004] 1. When entering the well, the safety joint or unsealing tool is often broken due to the heavy load of the liner or the unstable lifting and lowering operation;

[0005] 2. Due to complex conditions such as downhole scaling, sand production, casing deformation, etc., it is impossible to accurately calculate the starting tension of the safety joint or unsealing tool, or because the shear pin size design of the safety joint or unsealing tool is unreasonable, Failure to achieve the goal of unblocking and throwing away

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