低煤阶煤层气成藏特点与勘探开发技术

低煤阶煤层气藏具有煤层厚度大、渗透性好、含气量低但吸附饱和度较高等特征。国外近几年煤层气突破主要集中在美国粉河盆地、加拿大阿尔伯达盆地等低煤阶区，其勘探开发实践证实，低煤阶煤层气藏可以获得工业气流，达到商业开发规模。在介绍低煤阶煤层气勘探开发技术的基础上，对我国的低煤阶煤层气资源与勘探开发前景进行了初步分析、评估和展望。结果表明：我国低煤阶煤层气资源丰富，其中西部地区的准噶尔、吐哈、三塘湖、天山、塔里木、鄂尔多斯等盆地侏罗系低煤阶含气面积共计约20.68×10⁴ km²，煤层气资源量达19.96×10¹²m³，占全国煤层气总资源量的54％，具有很好的勘探开发前景。

Characteristics of Pooling and Exploration and Development of CBM in Lowrank Coals

CBM gas reservoirs in low rank coals are featured by large thickness of coal seams, high permeability, low gas content, and high adsorption saturation. In recent years, the major CBM discoveries are concentrated in the low rank areas in the Powder River Basin (the U. S. A) and the Alberta Basin (Canada). Exploration and development practices in these areas show that commercial gas flow can be obtained in CBM gas reservoirs in low rank coals. After introducing CBM in low rank coals exploration and development techniques, this paper preliminarily analyzes, assesses and forecasts the resource volume and exploration potential of CBM in low rank coals in China. It is shown that CBM resources in Low rank coals are rich in China. The Jurassic low rank coal seams in Junggar, Turpan Hami, Santanghu, Tianshan, Tarim and Ordos basins have a total gas bearing area of about 206 800 km2, and a CBM resource volume of 19.96 TCM accounting for 54% of the total in China, thus exploration and development potentials are large here.