Pressure test method for detecting seal performance of gas storage cavity of salt cavern

Abstract

Disclosed is a method for testing the cavity mechanical completeness integrity of the salt cavity air library. The method comprises steps of: laying down a suite of pressure testing pipe column, employing nitrogen or air as pressure testing media to test pressure in the salt cavity; measuring the variation value of the air-water interface depth during testing time, obtaining the readings of each well head meters in the testing time via ground detecting meter, and calculating the variation trend of the cavity leakage rate versus time; combining the variation of cavity air-water interface depth and the variation trend of the air leakage rate versus time to evaluate the cavity's mechanical completeness integrity.

Description

technical field [0001] The invention relates to a method for detecting the mechanical integrity of the cavity of an underground salt cavern gas storage, that is, a pressure test detection method for detecting the sealing performance of the cavity of the salt cavern gas storage. The method of injecting saturated brine and nitrogen into the well is used to complete the pressure test, which provides an effective operational basis for testing the tightness of the casing wellbore and cavity, and provides technical support for ensuring the safe operation of the gas storage in the future. The invention belongs to the technical field of petroleum and natural gas engineering. Background technique [0002] At present, the underground salt cavern gas storage is still blank in China, and the technical research in this field is also in its infancy. The cavity seal detection technology of salt cavern gas storage is unprecedented in China, and there is no unified method and detection stan...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: a large amount of gas injection, special interface measuring instruments are required, the test result is a periodic single value, and the evaluation result is inaccurate

The disadvantages of this method mainly include three aspects: (1) two sets of pressure test strings are required, and the test time is long, so the cost is high; (2) the performance of the wellhead instrument is high and the operability on site is poor; (3) if leakage occurs , this method cannot determine the specific leak location

[0005] In summary, it can be seen that API and Geostock gas storage cavity seal detection methods are difficult to meet the domestic demand for gas storage cavity pressure testing in terms of evaluation of pressure test results and on-site operability.

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