鄂尔多斯盆地东缘石西区块煤层气及致密砂岩气资源潜力评价

CBM and Compact Sandstone Gas Resources Potential Assessment in Shixi Block,Ordos Basin Eastern Margin

针对鄂尔多斯盆地东缘石西区块煤层埋深较深、致密砂岩气产气层数较多的特点,分析了区内煤储层特征,评价了深部煤层气和致密砂岩气的资源潜力。研究认为,工作区构造简单,以单斜构造为主,区块东部发育一系列规模较小的断层和褶皱,煤储层赋存稳定,有利于煤层气的富集;4(3+4)和9(8+9)号煤层含气性较好,其中9(8+9)号煤层资源潜力较大,是煤层气开发的主力煤层;致密砂岩气赋存主要受砂岩展布、构造发育和埋深的影响,在区块西部比较发育。研究表明,区块西部有利于深部煤层气和致密砂岩气多层共采,区块东部为煤层气单采有利区。

Considering deep coal buried depth and compact sandstone gas producing multilayer features in the Shixi block,Ordos Basin eastern margin have analyzed coal reservoir features in the area,assessed deep part CBM and compact sandstone gas resources potential.The study has shown that structures in the working area are simple,mainly monocline with a series of smaller scaled faults and folds in block eastern part,and steady coal reservoir hosting is propitious to CBM enrichment.Coal seam Nos.4(3+4)and 9(8+9)have better gas-bearing property,in which,coal No.9(8+9)has large resources potential,thus the principal coal seam for CBM exploitation.Compact sandstone gas hosting has mainly impacted by sandstone distribution,structural development and buried depth,better developed in block western part.The study has shown that block western part is propitious to deep part CBM and compact sandstone gas multilayer combined exploitation,while eastern part propitious to CBM separate exploitation.