Coal-bed methane mining method

Abstract

The invention discloses a coal-bed methane mining method. A plurality of adjacent reservoirs can be opened simultaneously, a main borehole communicates with horizontal sections and branch well sections of the multiple reservoirs, the multiple adjacent reservoirs play a synergistic effect, though the permeability increasing effect of the upper reservoirs, the permeability of the lower reservoirs is increased effectively, and the productivity is released to the utmost extent. According to the coal-bed methane mining method, the productivity is ensured, another borehole does not need to be additionally constructed, and thus the coal-bed methane mining cost of the multilayered-system reservoirs is lowered to a certain extent.

Description

technical field [0001] The invention relates to the technical field of energy mining, in particular to a coal bed gas mining method. Background technique [0002] Coalbed methane refers to the hydrocarbon gas stored in coal seams with methane as the main component, mainly adsorbed on the surface of coal matrix particles, and partly free in coal pores or dissolved in coal seam water. It is an associated mineral resource of coal and belongs to unconventional natural gas. Coalbed methane is a clean and high-quality energy and chemical raw material that has risen internationally in the past ten or twenty years. [0003] Ground drilling for coalbed methane mining involves setting up a horizontal well from the ground. The horizontal section of the horizontal well enters the unmined coal seam. The coalbed methane in the coal seam is desorbed by means of drainage and pressure reduction. The desorbed coalbed methane flows to the ground through the wellbore. The horizontal well incr...

AI Technical Summary

Problems solved by technology

However, the wellbore trajectory of the horizontal well passes through a target layer, and the scope of influence is limited. Only the coalbed methane in the target layer can be exploited, and the coalbed methane resources in the adjacent layers cannot be produced, and another wellbore needs to be constructed , in order to effectively develop multi-layer reservoirs, resulting in high cost of CBM exploitation in multi-layer reservoirs

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