Dual-gas co-mining device

Abstract

The invention discloses a dual-gas co-mining device which comprises a casing pipe, a first oil pipe, a second oil pipe and a bridge plug. During well-drain operation of a coal-bed gas well, perforation is performed on a tight sandstone layer, and the tight sandstone gas production layer or a shale gas production layer and a coal bed gas production layer is packed through the bridge plug; perforation is performed on the coal bed gas production layer; the second oil pipe and the first oil pipe with a sucker rod are sequentially placed into the casing pipe. The coal bed gas production layer is drained through a triple-extraction artificial lifting system, after a coal bed gas reservoir reaches desorption pressure, coal bed gas is annularly exhausted from the first oil pipe and the casing pipe, and gas production is achieved; the second oil pipe is used for performing tight sandstone gas exhaust and mining on the right sandstone layer or performing shale gas exhaust and mining on the shale layer. According to the dual-gas co-mining device, it is ensured that no series flow happens between different production layers, no airlocking happens during gas production, co-mining of dual gases of different buried depths and different gas production mechanisms is achieved, and the gas yield of the coal series gas well is effectively increased, and development economic benefits are increased.

Description

technical field [0001] The invention relates to the technical field of coalbed methane exploitation, in particular to a two-gas co-extraction device. Background technique [0002] The exploitation of coalbed methane is a process of water drainage and depressurization for gas recovery. By discharging the formation produced water around the wellbore, the bottom hole pressure is reduced to the desorption pressure of coalbed methane, so that coalbed methane is desorbed and produced. Usually, the pressure of coalbed methane is relatively low. ; The exploitation of tight sandstone gas is a process of self-depressurization and gas production. The tight sandstone gas is desorbed from the tight sandstone through pressure release. Usually, the pressure of tight sandstone gas layers is relatively high and the burial is deep; Sandstone gas is basically the same, produced from mud shale. [0003] Tight sandstone layers and shale layers are both buried deep, and coal seams produce a lot ...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, there is no downhole structure suitable for the co-production of coalbed methane and tight sandstone gas or coalbed methane and shale gas. big obstacle

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