Evaluation of Geological Conditions and Optimization of Favorable Areas for in-situ Pyrolysis Development of Tar-rich Coal in the Dananhu Mining Area, Turpan-Hami Basin
In-situ pyrolysis of tar-rich coal is considered a key pathway for achieving clean and efficient coal utilization, for which scientific potential evaluation and site selection are essential prerequisites and guarantees for its engineering implementation. The No.15 coal seam in the F1 South Mine Field of the Dananhu Mining Area, Turpan-Hami Basin, Xinjiang, was selected as the research object. A systematic analysis was conducted from five dimensions, including coal petrology and quality characteristics, coal seam occurrence conditions, surrounding rock conditions, sealing conditions, and environmental geological conditions. By utilizing a combined weighting method that integrates the AHP (analytic hierarchy process) and the EWM (entropy weight method), along with a fuzzy comprehensive evaluation method, 5 first-level and 13 second-level indicators were established. The comprehensive weight of each indicator was calculated for quantitative evaluation, and the feasibility of in-situ pyrolysis development in the study area was explored from multiple perspectives. Consequently, a multi-criteria evaluation model for the in-situ pyrolysis development potential of tar-rich coal was constructed, and favorable zones were identified. Most of the coal seams in the study area were found to meet the standard for tar-rich coal (average tar yield >7%), with tar-rich coal primarily developed in the middle-upper sections of the coal-bearing sequence. The No.15 coal seam is mainly composed of long-flame coal, with an average tar yield of 7.74%. It is characterized by moderate moisture content, low ash yield, high volatile matter yield, and low sulfur content. Overall, it is identified as a medium-thick to thick coal seam with a simple structure. The roof and floor lithology is dense, and the potential environmental risk is relatively low, making its comprehensive geological conditions the most suitable stratum for in-situ pyrolysis within the study area. Based on the model evaluation results, the favorability for in-situ pyrolysis development of the No.15 coal seam was classified into three grades. The favorable zones are mainly concentrated in the central-northern part, the relatively favorable zones (covering the largest area) are distributed in the southwest and east, and the unfavorable zones are primarily located in the southern part of the mining area. The evaluation model for in-situ pyrolysis potential of tar-rich coal constructed in this study can effectively overcome the subjective and objective limitations of single weighting methods and quantify complex and ambiguous geological conditions. It can provide a scientific and practical decision-making basis for the development and utilization of tar-rich coal resources in the study area, and is considered to possess value for broader application.
ZHAO Wei, CHE Ke-xin, WANG Wen-feng, HE Xin, GAO Xiang-quan, WU Jian, LIU Biao.
Evaluation of Geological Conditions and Optimization of Favorable Areas for in-situ Pyrolysis Development of Tar-rich Coal in the Dananhu Mining Area, Turpan-Hami Basin[J].
Science Technology and Engineering, 2026, 26(30): 13006-13019 DOI:10.12404/j.issn.1671-1815.2600810
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