A device and method for multi-layer blockage and leakage plugging based on one trip string

Abstract

The invention provides a multi-layer-section channeling sealing and leakage blocking device based on one-time pipe column tripping-in. The multi-layer-section channeling sealing and leakage blocking device comprises central pipe assemblies and at least one outer packing pipe assembly. The outer packing pipe assemblies comprise outer packing pipes, outer packers, sliding sleeve injection ports andsliding sleeve inner sleeves, wherein the outer packers and the sliding sleeve injection ports are arranged / formed on / in the outer packing pipes, and the sliding sleeve inner sleeves are located in the outer packing pipes and used for blocking the sliding sleeve injection ports. The central pipe assemblies are used for being tripped in the outer packing pipes of the at least one outer packing pipeassembly. The central pipe assemblies comprise central pipes, first packers, second packers and clamping spring pieces and further comprise blocking agent injecting pipes, wherein the first packers and the second packers are arranged on the central pipes, the clamping spring pieces are arranged between the first packers and the second packers, the blocking agent injecting pipes are arranged on the central pipes and communicate with the interiors of the central pipes, and injecting ports of the blocking agent injecting pipes are located between the first packers and the second packers. When blocking operation is conducted, the drilling plug operation procedure can be omitted, the cost is reduced, and the success rate of channeling sealing and leakage blocking is increased.

Description

technical field [0001] The invention relates to the technical field of solving the problem of channeling outside the casing or casing leakage after the production of casing cementing oil and gas wells, and in particular relates to a multi-layer channeling and leakage sealing device and method based on a single string. Background technique [0002] At present, most casing cemented oil and gas wells, after a certain period of production, are prone to problems such as water channeling outside the casing and gas channeling due to the quality of cementing and complex formations. Especially for heavy oil thermal recovery wells or high-temperature and high-pressure wells, frequent Alternating hot and cold, the cemented interface between the casing and the cement sheath is very prone to damage or separation, resulting in leakage outside the pipe or casing damage, which affects the normal production operations of oil and gas wells. The repair and plugging of casing damage and leakage...

AI Technical Summary

Problems solved by technology

[0005] Both of the above two processes require plug drilling, and there is a risk of secondary damage to the cement plug or plugging agent solidified outside the pipe after the plug is drilled. In addition, when the intubation bridge plug is used to seal channeling, the cost is relatively high, and there is a risk of injecting the pipe string. Due to the solidification of cement or plugging agent, the operation accident that cannot be pulled out from the intubation bridge plug; and when there are serious cases of multi-layer pipe leakage in the wellbore, it is necessary to carry out multiple trips of pipe strings and injection operations, time cost and higher operating costs

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