Research progress of tectonic control on coalbed methane development

In order to study the control mechanism of geological structure on CBM development,based on the geological background of the main coalbed methane development areas in China,this study systematically sorted out the previous research achievements,and focused on discussing the control effect of structure on the enrichment law and development effect of coalbed methane. Research shows that the high gas content and high permeability of coal reservoir are the key geological conditions to ensure the high yield of coalbed methane wells. Tectonic evolution and structural types affect the formation and enrichment process of CBM and determine the gas bearing property of coal reservoirs. The original permeability of reservoir is controlled by tectonic stress and structural fracture, and the coal structure affects reservoir modification and CBM production. The CBM development should firstly consider the enrichment degree of CBM and reservoir permeability, while taking into account the expansion and pressure relief effects of reservoir modification. Among them,for low-rank coal, the influence of structure on enrichment degree should be deeply explored,and for medium-high-rank coal,the constraint of structure on permeability should be highlighted. Based on the current situation that the analysis accuracy of local structural characteristics in the same regional structural background is insufficient,which leads to obvious differences in CBM development effect,the following three research directions for structural control of gas have been proposed. Establish a prediction model for coal seam gas enrichment based on structural complexity. The influence mechanism of deep structure on the enrichment and development of CBM is analyzed. Based on the current structural characteristics,the control effect of multi-field coupling on the CBM development is studied.