论贵州煤层气地质特点与勘探开发战略

Geological Condition, Exploration and Exploitation Strategy of Coal-bed Methane Resources in Guizhou, China

贵州煤层气地质条件具有"一弱、两多、三高、四大"的特点,即龙潭组富水性弱,控气构造类型多和煤层层数多,煤层含气量高、资源丰度高、储层压力及地应力高,以及煤层气资源量大、煤级变化大、煤层渗透性变化大和地质条件垂向变化大。贵州煤层气的赋存特点,一方面体现出其煤层气资源富集程度高、储层能量大、开发潜力巨大的优势;另一方面存在影响煤层渗透性及储层改造的不利因素,因此煤层气勘探开发需要寻找新的思路与方法。针对贵州省目前煤层气地质研究程度,提出近期应加大对煤层气勘探开发投入,准确摸清全省煤层气资源潜力状况,在此基础上分析各类煤层气开发技术对煤层气地质条件的适应性,进而合理制定煤层气资源勘探开发利用战略与规划。根据贵州省煤层气的开发现状建议将织纳煤田作为现阶段煤层气地面勘探开发的主攻区域,借鉴煤层气开发晋城模式,尽快在未采动区实施以地面直井和丛式井组为主的上部煤层群煤层气开发先导性示范工程;对六盘水及其他煤田则可借鉴淮南模式,通过远距离保护层大面积采动卸压,综合利用采前、采中、采后矿井和地面煤层气抽采技术,实施采动区煤层气开采,继而建设与之配套的分布式煤层气小型化利用、储运技术与装置。

There are four remarkable characteristics of coal-bed methane （CBM） geology in the Guizhou Province, China. The characteristics show the predominance of richer CBM resources, higher coal-bed energy and tremendous exploitation potential in Guizhou on the one hand, and disadvantageous conditions of coal bed permeability and reservoir reconstruction on the other hand. So, it is inescapable to look for new thoughts and methods on CBM exploration and exploitation. The authors considered that in the near future the potential of CBM resources and adaptability of various CBM technologies to the CBM geological conditions in the province should be figured out, then proceed to set down the strategy and programming of CBM exploration and exploitation. It is suggested that pilot demonstrating CBM engineering with surface vertical and cluster wells should be the top-priority in the Zhijin-Nayong coalfield and CBM mine extraction might be preferential in the Lupanshui coalfield.