HYDROGEOLOGY OF EXPLORATION AND DEVELOPMENT PILOT AREA FOR COALBED METHANE IN LIULIN

The regional hydrogeological conditions are simple in Liulin pilot area.The adjoining aquifers are the main source of coalbed water,and the saturability of movable water reaches 30% in No.4 and 8 coal seams.The fractures and cleats are the storage space and migration channel for free water.The waterbearing behavior,water activity and water yield in No.8 seam are stronger than those of No.4 and 5 seams.The seam from which the water is pumped and the main water-produced layer during multi-seam mining are identified using Stiff ion diagram.The status of seam water are normal to over-pressure a little.The regions with steeper hydraulic gradient are the favorable ones to set the developing wells.