鄂尔多斯盆地乌审煤田煤层气地质特征与勘探开发前景

Geological characteristics and prospects for exploration of coalbed methane in Wushen coalfield , Ordos Basin

鄂尔多斯盆地乌审煤田是我国煤层气勘探的重要区块。为搞清该区煤层气藏富集规律,通过气测录井和现场解吸等手段研究了该区煤层气地质特征;通过分析不同煤层气井的含气量、煤层顶底板岩性等资料,认为影响勘查区煤层气富集的关键因素是上覆有效盖层的厚度;通过煤层气样的气体组分分析,确定了甲烷风化带的大致影响范围。预测结果显示,乌审煤田煤层气主要赋存于中、北部3-1煤层800 m以深地区,顶底板封盖良好区域含气量可达到8 m3/t,具有良好的勘探开发前景。

The Wushen coalfield, Ordos Basin is one of important coalbed methane （CBM） development areas. In order to study CBM storage regularities the CBM geological characteristics in this area are studied through analyzing logging data and gas desorptiondata on site, and the gas content and lithological properties of coal seams in different CBM wells are analyzed. It is considered that the key factor controlling gas storage is the effective thickness of overburden layers of coal seams in exploration area. Based on gas content analysis results the scope of weathered zones is determined. The final predicted results indicated that the CBM resources are mainly distributed in the center and northern areas Of Wushen coalfield and the gas content of Coal Seam 3-1 can reach up to 8 m^3/t at the depth shallower than 800 m, Where the industrial development potential is favorable.