Depleted oil-gas reservoir underground gas storage injection-production string and operating method thereof

Abstract

Disclosed are a depleted oil-gas reservoir underground gas storage injection-production string and an operating method thereof. In order to construct an underground gas storage by a depleted oil-gas reservoir, a safety valve (1), a telescopic pipe (5), a circulating sliding sleeve (6), a packer (8) and a locating pup joint (9) of the injection-production string are sequentially connected from top to bottom through a tubing (7), and a perforating gun (10) is mounted at the lower end of the tubing (7) and positioned in a gas reservoir (11). By the aid of injection-production well completion interaction process technology, the bottom end of a well completion string is connected to a perforating string and goes down to a well, the perforating string is thrown into a well bottom by a releaser after perforating, test and production can be performed, pollution of a perforated oil-gas layer caused by well control fluids in double trip of the strings is avoided, and operating steps are simplified. The injection-production string has the advantages the structure is reasonable, process perforating, testing, well completion and gas injection and production are completed once, the reservoir is effectively protected, and late well control and repair are omitted.

Description

technical field [0001] The invention relates to an injection-production string of an underground gas storage, in particular to an injection-production string of an underground gas storage of a depleted oil and gas reservoir and an operation method thereof. Background technique [0002] The types of underground gas storage generally include rock salt caverns, depleted oil fields, underground aquifers, and depleted oil and gas fields. [0003] Salt cavern underground gas storage has a small storage capacity; salt layer creep can easily cause casing damage, resulting in a large volume loss; brine discharge and leakage may cause gas loss; There are certain risks in terms of sealing and stability. [0004] The gas storage rebuilt in the depleted oilfield has unrecoverable residual oil in the oil reservoir, and a certain amount of crude oil is carried in the recovered gas, which requires special treatment, which limits its application. [0005] Because there is no gas in the und...

AI Technical Summary

Problems solved by technology

[0003] Salt cavern underground gas storage has a small storage capacity; salt layer creep can easily cause casing damage, resulting in a large volume loss; brine discharge and leakage may cause gas loss; There are certain risks in sealing and stability

[0004] The gas storage rebuilt in the depleted oil field has unrecoverable residual oil in the oil reservoir, and the recovered gas carries a certain amount of crude oil, which requires special treatment, which limits its application

[0005] Because there is no gas in the underground aquifer gas storage, the amount of cushion gas required is relatively large, and this part of the gas cannot be produced, and the gas-water interface is difficult to control. The "gas-driven water" method is easy to generate gas Tapering, so the cost of building a library is high and the construction period is long

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