沁水盆地煤层气成藏主控因素与成藏模式分析

摘要

沁水盆地石炭-二叠系煤层厚度大、分布稳定、演化程度高，具有良好的煤层气勘探潜力，是目前国内首个成功商业化开发的煤层气盆地。基于研究区已有地质成果，对影响沁水盆地煤层气富集成藏的主控地质因素与成藏模式进行分析，认为构造运动、水动力条件、煤层埋深、煤岩组成及热演化程度是控制沁水盆地煤层气成藏的主要地质因素，高镜质组含量、高热演化程度、弱水动力条件和较大的埋深是煤层气成藏的有利条件，向斜是煤层气富集成藏的有利部位。%The Permo-Carboniferous coal seams in the Qinshui Basin have large thickness and stably distributed with high evolution grade and good CBM exploration potential, thus the first successfully commercial exploited CBM basin in the country. Based on avail-able geological data in the study area, analyzed main controlling factors of CBM reservoiring and reservoir patterns in the basin, consid-ered that the tectogenesis, hydrodynamic condition, coal buried depth, lithotype of coal and thermal evolution grade are the main con-trolling geological factors to impact CBM reservoiring in Qinshui Basin. While the high vitrinite content, high thermal evolution grade, weak hydrodynamic condition and rather large buried depth are advantaged conditions to CBM reservoiring;synclines are favorable set-ting to CBM enrichment and reservoiring.