Coalbed methane mining method in horizontal open-hole diversion tank well and Tanghulu well

Abstract

The invention discloses a method of cutting a set of diversion grooves with a certain depth and phase angle in the coal seam near the wellbore by using a fluid cutting gun in a horizontal open-hole section of a coal seam, and using a high-pressure air-water mixed fluid to form the diversion grooves well, and in the horizontal well section of the coal seam, alternately cut diversion grooves and a series of caves with a certain spacing and a certain diameter to form a series of cave wells connected by the wellbore and the diversion groove - Tanghulu well, and the two types of wells. A method for exploiting coalbed methane by forming a well group.

Description

[0001] The invention relates to a coalbed methane mining method in the field of coalbed methane mining, in particular to a method of using a fluid cutting gun in the horizontal open hole section of the coal seam, and using a high-pressure air-water mixed fluid to cut a group of holes with a certain depth in the coal seam near the wellbore. Diversion grooves with phase angles form diversion groove wells, and alternately cut diversion grooves and a series of cutting caves with a certain spacing and a certain diameter in the horizontal well section of the coal seam to form caves connected by wellbore and diversion grooves The method of exploiting coalbed methane by stringing wells-tanghulu wells and the well group composed of the second type of wells. Background technique [0002] In the field of coalbed methane exploration and exploitation, the mining of coalbed methane is usually achieved by drilling coalbed methane wells and desorbing methane gas in the coal seam to produce it ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the low gas production of vertical wells, which is not conducive to the management of centralized drainage and gas recovery, and the production cost is high, especially the enhanced fracturing causes a large amount of pulverized coal to be produced in the process of drainage and gas recovery, which leads to the diversion of fractures in the coal seam Channel blockage will reduce gas and water production, and even bury the drainage pipe string, resulting in the shortcomings of frequent workover. In order to overcome the pollution of coal seams during drilling of horizontal wells, horizontal multi-branch wells and inverted umbrella well groups, and the coal seams during drainage Collapse is easy to block the wellbore, it is difficult to maintain the wellbore due to collapse and blockage, the coal seam in the large horizontal open hole section cannot be strengthened and reformed, and the original gas-liquid drainage and diversion channels (cracks, cracks) have limited capacity, etc.

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