鄂尔多斯盆地西缘桌子山矿区煤层气成藏模式

CBM reservoir-forming model of Zhuozishan mining area in western margin of Ordos basin

为了厘清鄂尔多斯盆地西缘桌子山矿区的煤层气成藏条件,对区内主力煤层的厚度、埋深、煤岩煤质、含气性、顶底板封盖性以及水文地质条件进行了系统分析。研究区煤层厚度较大、埋深适中、生烃物质基础丰富、含气量高、封盖条件较好,具有较有利的成藏条件。综合分析矿区构造形态、顶底板封盖性及水文地质条件,提出了断层与盖层封堵型、叠瓦扇式逆冲断层与水力封堵型、多煤层自封闭型3种煤层气成藏模式。

In order to clarify accumulation conditions of coalbed methane（CBM）of Zhuozishan mining area in Inner Mongolia of Northwest China, the paper systematically analyzed the thickness, burial depth, coal petrology and property, gas content, roof and floor sealing and hydrogeological conditions of the main coal seams in the study area. The study area has favorable accumulation conditions with large thickness of coal seams, appropriate depth, abundant hydrocarbon-generation matter, high gas content and well sealing conditions. Based on the comprehensive analysis of the structure form, roof and floor sealing, and hydrogeological conditions of the study area, three types of CBM reservoir-forming models were put forward： that is the type of faults and cap rock sealing, the type of imbricate fan of thrust faults and hydraulic type of self-enclosed multiple coal seams.