Coal bed methane vertical well double-layer partial pressure combined production method and its device

Abstract

The invention relates to a vertical-well double-layer partial-pressure commingling method and device for coalbed methane. The method includes the steps that a pipe is arranged in the well, and three isolated channels including the first channel, the second channel and the third channel are arranged in the pipe; the side wall of the first channel and the side wall of the second channel are communicated with two coal beds respectively, gas of the two coal beds is discharged to a well opening through the first channel and the second channel respectively, liquid of the two coal beds flows to the bottom of the first channel and the bottom of the second channel respectively, and gas-liquid separation is achieved in the well; one-way valves are arranged between the first channel and the second channel and between the second channel and the third channel, and the liquid of the two coal beds is jointly drawn out of the well while accumulated liquid in the well bottom is avoided. According to the method and device, the gas and the water generated by the upper coal bed and the lower coal bed are jointly mined and jointly drawn through the single well, gas-liquid separation is carried out at the well bottom, the gas is drawn through a gas path, the liquid is drawn through a liquid path, pressure systems of the two coal beds are separated, interlayer interference generated during exploitation is reduced, and the gas yield is effectively increased.

Description

technical field [0001] The invention relates to the field of coal-bed methane exploitation, in particular to a method and a device for the combined production of double-layer partial pressure in a vertical well of coal-bed methane. Background technique [0002] Qinshui Basin is the main coalbed methane research area and development area in my country, where there are two sets of mineable coal seams, 3# and 15#. The 15# coal seam and its surrounding rocks contain a large amount of formation water, and the reservoir stability is not good, and a large amount of coal dust is easy to be produced during mining, while the 3# coal seam has relatively favorable hydrogeological conditions [1]. Therefore, the 15# coal seam has not yet For large-scale industrial production, the existing production well pattern is mainly deployed for the 3# coal seam. In order to achieve the coalbed methane production target of the "Twelfth Five-Year Plan", it is required to gradually realize the joint ...

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Problems solved by technology

The 15# coal seam and its surrounding rocks contain a large amount of formation water, and the reservoir stability is not good, and a large amount of coal dust is easy to be produced during mining, while the 3# coal seam has relatively favorable hydrogeological conditions [1]. Therefore, the 15# coal seam has not yet For large-scale industrial production, the existing production well pattern is mainly deployed for the 3# coal seam

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