蜀南地区龙潭组煤层气储层特征及资源潜力

据中国多次开展的煤层气资源评价结果，蜀南地区煤炭以无烟煤为主，与沁水盆地类似，其煤层变质程度高，吸附能力强，含气量高，蕴藏了大量的煤层气资源。为了进一步查明蜀南地区煤层气储层特征及其资源潜力，根据该区测井资料、录井资料、煤层气参数井资料，从煤层分布特征、煤质特征、孔-裂隙发育特征、含气性特征及等温吸附特征等方面，分析了该区煤储层特征，对储层质量进行综合评价，并在此基础上评价其资源潜力。结果表明，蜀南地区龙潭组煤变质程度高，属于无烟煤；兰氏体积大，含气量高，气体质量好，含气饱和度高，兰氏压力小，临界解吸压力小、地解比偏低。综合评价显示该区煤层气储层质量较好，资源潜力大，但开发难度较大，尚需适宜的开采技术。建议选择长宁-叙永区块开展煤层气勘探开发试验，探索煤层气勘探评价方法及有效的开采技术。

Characteristics of CBM Reservoirs and Their Resource Potential in the Southern Sichuan Basin

According to the results of several coalbed methane(CBM) resource evaluations, the coal in the southern Sichuan Basin is mainly anthracite, similar to that of the Qinshui Basin. The coal bed in the southern Sichuan Basin contains a large amount of CBM resources due to the high degree of coal metamorphism, strong adsorption capacity, and large gas content. The CBM reservoir characteristics in the southern Sichuan Basin, such as the coal layer distribution, coal rock quality, pore-fracture features, gas content, and isothermal adsorption features of the coal beds, were analyzed and the coal reservoir quality and CBM resource potential were evaluated in this study using logging and CBM parameter well data. The results show that the regional coal development is unstable because of an overall great burial depth and high degree of coal metamorphism. The coal reservoirs have a large Langmuir volume, high gas content, good gas quality, high gas saturation, small Langmuir pressure, and small critical desorption pressure. The comprehensive evaluation shows that the CBM reservoir has a good quality and great potential; however, its development is relatively difficult. Therefore, suitable mining technology is needed. We selected the Changning-Xuyong block as the experiment area for CBM exploration and development to determine CBM evaluation methods and effective mining technologies.