Coalbed methane enrichment prediction and resource estimation for the areas with different tectonic complexities

Abstract

Geological tectonic movement plays a controlling role in the distribution pattern of coalbed methane (CBM) resources. The traditional CBM resource estimation methods use the measured CBM as the overall CBM content and do not consider the influence of geological structure on the nonuniform distribution of CBM resources. In this paper, the geological structure of the Guojiahe coalfield in the northern Yonglong mining area, China, was used as the research background. Based on the precise three-dimensional (3D) seismic interpretation results of the coal seam geological structure and the tested CBM contents at sampling points, a fuzzy comprehensive evaluation method was used to classify the tectonic complexity of the study area, and the CBM contents of different tectonic locations in the tested coal seams and the results determined by the finite element method were analyzed. On this basis, a quantitative relationship between the tectonic complexity index and the amount of CBM resources was established, and finally, a CBM-enrichment prediction model and a CBM resource estimation method for areas with different tectonic complexities were proposed. The agreement between the amount of CBM resources obtained by the estimation method and the actual exploration result is 85.2%; therefore, the proposed method has a theoretical guidance and engineering application value for the exploration and precise development of CBM resources.

Three-Dimensional Geological Modeling of Coal Reservoirs and Analysis of Sensitivity Factors for Combined Mining Capacity

“…In the analysis of CBM production capacity, previous research primarily considered a comprehensive range of factors, such as geological parameters, reservoir fracturing and construction parameters, and drainage and production work systems, to determine the principal factors influencing production capacity [1,2]. Some studies have also conducted in-depth analyses of geological parameters, including structural characteristics, stress distribution, and hydrological features, and their relationships with CBM well production to identify favorable development areas [3][4][5][6]. Furthermore, there have been investigations into the impact of drilling and completion parameters on production capacity, offering theoretical support for optimizing engineering processes [7].…”