Structural control on the enrichment of CBM in Changgang syncline, northern Guizhou coalfield

The coal seam of Changgang syncline has the characteristics of many layers of coal seam, thin single layer, but the high gas content. The existing CBM wells show that the area has a certain potential for CBM exploration and development. However, the study on the enrichment of CBM is blank in the aera. Based on the data of coal geology, drilling and related test data of Changgang syncline, a brief analysis of the coalbed methane accumulation in this area have been made. The influence of tectonic action on coalbed gas enrichment in this area is analyzed. It can provide a certain direction for further exploration and development of CBM in Changgang syncline. Changgang syncline axis is favorable area for CBM enrichment, and the content of CBM is over 20 m³/t. The gas content in axial part of the syncline is high, and lower in the syncline wings. And the turning parts of synclinal axis also have lower gas content. In addition, the normal fault can cause the dissipation of CBM. The lowest CBM content is about 10 m³/t. The pressure fault has little effect on it.