Method for detecting casing leakage

Abstract

The invention relates to the technical field of oil field oil well drilling and production, in particular to a method for detecting casing leakage. The method includes the steps of firstly, placing a casing leakage detecting device into a well casing, allowing an upper packer and a lower packer to be respectively located at the upper end and the lower end of a section loop, continuously applying pressure into a central pipe, and allowing the floating valve of a combined bottom valve to seal the lower portion of the central pipe after the pressure reaches a set value; secondly, continuously applying pressure into the central pipe, and allowing a pressure difference type opening valve to be communicated with the well casing; thirdly, continuing applying pressure into the central pipe to allow gas to enter between the section loop and the casing leakage detecting device, and then maintaining the pressure; fourthly, observing whether a pressure gauge changes or not; fifthly, applying pressure into a gap between the well casing and the casing leakage checking device if the section loop has no problem, maintaining the pressure, observing the conditions of the pressure gauge, and determining that the section loops above the section loop have no problems if the pressure gauge does not change. The method has the advantages that leakage points can be detected precisely, and high detecting speed is achieved.

Description

technical field [0001] The invention relates to the technical field of drilling and production of oil wells in oil fields, in particular to a casing leakage inspection method. Background technique [0002] Due to reasons such as cementing quality, connecting thread, formation movement, and corrosion, the oil well casing has leakage phenomenon, which brings unfavorable factors to the construction of oil well measures and affects the crude oil production. Once the leakage occurs in the non-producing layer of the oil well, the leakage point must be determined before repairing. The current method for verifying the leakage point of the casing is generally to use a packer to seal the oil casing annulus above the production layer and pressurize the casing. Verify the bushing. However, several existing packers have unfavorable factors in varying degrees during the implementation of the test set construction process, resulting in unsmooth construction and an inability to accurately ...

AI Technical Summary

Problems solved by technology

However, during the construction of several current packers, there are unfavorable factors to varying degrees, which lead to unsmooth construction and the inability to accurately judge the leakage position.

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