Analysis of classification and causes of water production in CBM reservoir

With the methods of statistical analysis and numerical simulation, this study classifies CBM reservoir into 4 types by water production, namely:ultra-low water production CBM reservoir with under 1m³ water production per day, low water production CBM reservoir with 1~5m³ water production per day, medium water production CBM reservoir with 5~20 m³ water production per day, high water production CBM reservoir with over 20m³ water production per day. The causes of high water production and low water production in CBM reservoir were analyzed deeply, finding out that the property of the coal seam roof aquifer, the tectonic conditions of the CBM reservoir and the fracturing measures mainly causes high water production in CBM reservoir, the physical property of the CBM reservoir mainly causes low water production in CBM reservoir, at the same time, producing institution also has an indirect effect on the water production in CBM reservoir. Then this study gives further suggestions on the development of CBM reservoir with high water production, ultra-low water production and unsatisfied gas production.