盘江矿区月亮田矿煤储层物性差异分布特征及其控制机理

为了综合分析盘江矿区月亮田矿煤层气勘探开发地质条件与潜力,研究采用多种测试手段,系统分析了该矿煤储层在孔隙度及孔隙结构、渗透性和储层压力在垂向分布的特征与差异。结果表明,盘江矿区月亮田矿二叠系龙潭组煤储层孔隙度较低,小孔体积占明显优势并且比例接近,微孔和小孔比表面积占优势但变化较大,主要发育狭缝状孔和细径广体的墨水瓶状孔。该区煤层渗透率在垂向上的变化较大,且并非为应力主控,受多种地质条件的综合影响。龙潭组煤储层压力属于异常低-异常高压范围,随埋藏深度的增加而增大,推测区内龙潭组煤系地层在垂向上至少存在2个独立含煤层气系统。针对龙潭组煤储层物性垂向分布特征的研究,期望可以为月亮田矿煤层气开发提供新的地质参考。

Coal Reservoir Physical Property Differences Distribution Features and Control Mechanism in Yueliangtian Coalmine,Panjiang Mining Area

To comprehensively analyze CBM exploration and exploitation geological conditions and potential in the Yueliangtian coalmine,Panjiang mining area,the study has used multiple test means,systematically analyzed coal reservoir porosity and pore structure,permeability,reservoir pressure vertical distribution features and differences.The result has shown that the Permian Longtan Formation coal reservoir has rather low porosity in the area;minipore volume holds obvious preponderance and proportions are close to;specific surface areas of micropore and minipore hold preponderance but varied greatly;mainly have developed slit shaped pores and thin neck wide body ink-bottle shaped pores.Vertical variation of coal seam permeability is rather large in the area,not mainly controlled by stress,but comprehensively impacted by multiple geological conditions.Longtan Formation coal reservoir pressure is within very low to very high range,increasing with buried depth increasing.It is presumed that in the area’s Longtan Formation coal measures strata vertically at least have 2 independent CBM-bearing systems.Based on Longtan Formation coal reservoir physical property vertical distribution features study can be expected to provide new geological references for CBM exploitation in Yueliangtian coalmine.