Analysis of Productivity Characteristics of Coalbed Methane Based on 3D Geological Modeling

Using the geological modeling software, based on the production data of 138 CBM wells in No.3 coal seam of western Sihe minefield from 2007 to 2017, the production capacity of the study area can be divided into three zones: A, B and C. The plane and profile characteristics of coal structure and the temporal and spatial variation characteristics of productivity were compared and analyzed. The results show that the study area is mainly composed of primary structure and contains a small amount of structure coal, It basically contains no broken grain structure coal and mylonite structure coal. Regional distribution of broken structure coal content is C>B>A. Take C as the center, the broken structure coal content gradually decreases to zone A and zone B. For the capacity distribution, the average daily CBM production is A>B>C. Most wells with good CBM production capacity are distributed in the A and B zones. The C-zone has a large distribution of production-attenuated CBM wells. Although the content of broken structure coal content has a great contribution to the early production capacity of CBM wells, it is bad to the sustainability of production capacity. In the C zone with broken structure coal content of about 18%, the early gas production is higher and the decay is faster.