Coalbed methane horizontal well hole collapse cave-building pressure relief developing system and method

Abstract

The invention discloses a coalbed methane horizontal well hole collapse cave-building pressure relief developing system and method. An inlet of an abrasive mixing device in the system separately communicates with a liquid storage tank and an abrasive tank, an outlet of the abrasive mixing device communicates with an inlet of a ground power device, an outlet of the ground power device communicateswith an underground injection device, and the underground injection device is positioned at the position, near a wellhead, of the horizontal section of a horizontal well. After chambering cave-building barefoot well completion of the horizontal well are completed, the mixed fluid is delivered to the underground at a certain frequency through the ground power device and sprayed out through the underground injection device, so that the pressure pulsation excitation and stress release in the horizontal well of structured coalbed methane are realized, the coal-liquid-gas mixture moves along the pressure relief space to the vertical well section through hydraulic displacement. The coalbed methane horizontal well hole collapse cave-building pressure relief developing system and method can realize the pressure relief and stress release of tectonic coal in-situ horizontal well hole collapse cave-building and provide a basis for realizing the efficient and continuous mining of the tectonic coalin-situ coalbed methane.

Description

technical field [0001] The invention relates to a pressure relief development system and method for a coalbed methane horizontal well, in particular to a pressure relief development system and method for a coalbed methane horizontal well collapsed hole and cave making, and belongs to the field of coalbed methane exploitation. Background technique [0002] Structural coal refers to the coal that is affected by tectonic stress, and the original structure and structure are damaged by strong cracks, resulting in tectonic changes such as fragmentation, crumpling, and polishing. The extensive development of tectonic coal and the abundance of tectonic coal-bed methane resources are notable features of China's coal and CBM resources. Structural coal resources account for a high proportion of my country's discovered coal resources. proportion is greater. Structural coal has outstanding characteristics such as rich gas, low permeability, and softness. Most of them are coal and gas out...

AI Technical Summary

Problems solved by technology

[0003] The method based on the theory of hydrophobic decompression and desorption gas recovery is the main method for the development of in-situ coalbed methane surface wells. Due to the extremely low permeability of structural coal reservoirs and the poor effect of hydraulic fracturing and other reconstruction methods, the theory of hydrophobic decompression and desorption gas recovery It is not suitable for structural coal reservoirs. The results of exploration and development practice also show that the coalbed methane exploration and development technology based on the theory of hydrophobic decompression desorption gas production includes SVR technology series (vertical well fracturing, U-shaped well, multi-branched horizontal well, Horizontal well fracturing, etc.), ECBM technology series (CO 2 -ECBM,N 2 -ECBM, etc.) and its composite technology cannot realize the efficient development of structural coal CBM

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