Horizontal bare hole flow guiding slot well and method for mining coal bed gas of sugarcoated haw well

Abstract

The present invention discloses a method for exploiting coal-bed methane in a horizontal open-hole diversion trench well and a cavity string well. In a coal-bed horizontal open-hole well section, a fluid cutter adopts high-pressure air-liquid mixture fluid to cut a group of diversion trenches with a certain depth and a certain phase angle in a coal bed neighboring a borehole until the diversion trench well is formed, and, in a coal-bed horizontal well section, alternately cut diversion trenches and a string of cavities with a certain interval and a certain diameter until the cavity string well, in which the borehole is communicated with the diversion trenches, is formed.

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-sugar gourd wells, and well groups 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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