Influence of Coal-Seam Water on Coalbed Methane Production: A Review

We present a comprehensive overview of the influence of water on coalbed methane production. The influence of water on coalbed methane production is associated with adsorption of water in pores, capillary condensation, micropore filling, adsorption hysteresis and its effect on methane diffusivity, coal swelling due to adsorption of water and a corresponding change in methane permeability, pore saturation by water (water imbibition into pores), and gas-water two-phase flow in the cleats. We consider methods for reducing the negative impact of water on coalbed methane production: carbon dioxide injection and microwave technology. We identify promising areas of study.