Method for detecting setting effect of packer in salt-cavern gas storage

Abstract

The invention relates to a method for detecting a setting effect of a packer in a salt-cavern gas storage. The method comprises the following steps: 1) washing a well after tripping in an injection-production casing; 2) injecting nitrogen into an annulus between the injection-production casing and a production casing, pressurizing brine in the annulus to below a packer setting position; 3) after setting the packer, continuing to inject nitrogen into the annulus to pressurize so that an annulus pressure of the packer at least is 1.1 times greater than an upper limit pressure of the salt-caverngas storage; 4) tripping in a gas-liquid interface inspection device in the injection-production casing, and detecting a gas-liquid interface below the packer between the injection-production casing and the production casing; 5) detecting and recording the depth of the gas-liquid interface, the wellhead pressure of the injection-production casing and the annulus pressure; and 6) judging the setting effect of the packer according to change situations of the gas-liquid interface below the packer, the wellhead pressure of the injection-production casing and the annulus wellhead pressure. The method is strong in practicability, simple to operate, high in airtightness detection precision, and helpful for effectively verifying the setting effect of the packer, so as to prolong the life of the salt-cavern underground gas storage and ensure safe and effective operation of the same.

Description

technical field [0001] The invention relates to a detection method for the setting effect of a packer of a salt cavern gas storage. Background technique [0002] Salt cavern underground gas storage technology is a new type of natural gas storage technology. It reaches the salt layer or salt dome by drilling, and uses artificial water dissolution to form a cave storage space in the salt layer or salt dome to store natural gas. . Compared with surface gas storage technology, salt cavern underground gas storage has the advantages of small footprint, large storage capacity, and high safety performance. It has also begun to be used as a peak-shaving gas storage on a large scale in China, and has a good prospect. However, the airtightness of the salt cavern underground gas storage directly affects the service life and operation safety of the gas storage, and the setting effect of the packer plays an important role in the airtightness. If the setting effect of the packer in the s...

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Problems solved by technology

[0004] Therefore, the detection method of packer setting effect commonly used in the oil and gas industry can no longer meet the requirements of long-term safe operation of salt-cavern underground gas storage

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