准噶尔盆地南缘硫磺沟煤层气富集主控地质因素及有利区优选

摘要

To evaluate the exploration and development potential of coalbed methane (CBM)and instruct the safety production of coal mine,the reservoir properties in Liuhuanggou coal mine in southern margin area of Jungger Basin were analyzed,including the maceral,fracture and gas content of main coal seams of No. 4-5 , No. 7 and No. 9-1 5 .Combined with the data from field drilling data and gas desorption and emission,the geo-logical controlling factors of CBM in this region were investigated from aspects such as structures,sedimentary environments,burial depth of coal and hydrodynamic conditions.The results show that the coal reservoir in this region has favorable properties,in which the pore-fracture system has well developed and the density of micro-fractures reaches to 3,935 per 9 cm2;moreover,the gas content is high,and CBM content in No. 4 -5 coal seam is from 4. 88 to 1 0. 81 m3/t with an average of 6. 56 m3/t.The analysis of factors affecting gas content in coal seam indicates that the gas controlling mode gives priority to structure and hydrodynamic conditions.At last,by using the multi-level fuzzy comprehensive evaluation model the CBM favorable region in No. 4-5 coal seam is predicted to be the area surrounding boreholes of 29-3 and 28-3 .%为评价煤层气资源勘探开发潜力和指导矿井安全生产，对准噶尔盆地南缘硫磺沟煤矿主煤层（4－5、7、9－15号煤）的储层物性特征（显微组分、裂隙及含气性等）进行了测试分析，结合现场钻井资料、瓦斯解吸及瓦斯涌出量等资料，从构造、沉积、煤层埋深、水动力条件等方面分析了该区煤层气的控气地质因素。结果表明：煤储层物性较好，孔裂隙较为发育，微裂隙高达3935条／9 cm2；煤层含气性（瓦斯含量）较好，4－5号煤层为4．88～10．81 m3／t，平均6．56 m3／t。控气地质因素分析表明，准南硫磺沟煤层气的控气模式以构造－水动力耦合控气为主。同时，利用多层次模糊数学综合评价模型，预测的硫磺沟煤矿（4－5号煤）煤层气赋存有利区为钻孔29－3和28－3周边区域。