Casing leakage repairing method

Abstract

The invention discloses a casing leakage repairing method, and belongs to the field of oil field underground plugging operation. The casing leakage repairing method comprises the steps that a packer is set below the position, to be subjected to leakage repairing, of a casing; pipe scraping operation is conducted on the inner wall of the casing; a cleaning agent is injected into the casing, and still standing is carried out; well washing operation is conducted on the inner wall of the casing; a blast pipe is put down into the casing, so that a pipe opening of the blast pipe is located below the position, to be subjected to leakage repairing, of the casing; the air humidity at an inlet of the blast pipe and the air humidity at an outlet of the casing are detected, and when the air humidity at the inlet of the blast pipe is consistent with the air humidity at the outlet of the casing, blast is stopped; and a plugging agent is injected into the casing, so that the plugging agent blocks the position, to be subjected to leakage repairing, of the casing. According to the casing leakage repairing method, impurities such as salt scale, hard wax, rust and a water film adhered to the inner wall of the shallow casing can be thoroughly cleared, so that the plugging agent and the casing can be fully adhered, and the leakage repairing effect is ensured.

Description

technical field [0001] The invention belongs to the field of downhole plugging operations in oil fields, and in particular relates to a casing leakage repairing method. Background technique [0002] With the continuous development of oilfields, the casing leakage problem has been aggravated due to the influence of various factors such as casing corrosion. Casing leakage not only affects the normal production of oil and water wells and reduces crude oil production, but also increases operating costs due to leakage repair, and some oil and water wells are even shut down due to casing leakage. [0003] In related technologies, chemical plugging methods and mechanical plugging methods are generally used to deal with casing leakage. The chemical plugging method is to inject a plugging agent into the leaking part of the casing, so that the plugging agent and the casing are fully bonded to fill the leaking part of the casing, so as to achieve the purpose of repairing the leakage o...

AI Technical Summary

Problems solved by technology

[0004] However, due to the presence of a large number of impurities on the inner wall of the casing, such as salt scale, hard wax, rust and water film, etc., the plugging agent and the casing cannot be fully bonded, and the leakage repair effect is not good.

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