YCN煤层气富集地质因素分析

Geologic factors analysis of YCN coalbed methane enrichment area

以YCN区块为例研究了煤层埋深、厚度、构造、顶底板岩性及水文等地质条件与含气量的关系。研究结果表明:含气量随着煤层埋深的增加而增加,但是超过"临界深度"后,含气量开始逐渐下降;煤级越高,含气量越大;灰分变化与含气富集呈弱正相关关系;煤层顶底板厚度、岩性组成、水文地质条件、构造稳定性等地质条件越有利于保存,煤层气越富集。研究结果为高效开发YCN及类似的煤层气田提供了理论依据。

Taking YCN block for example, relation between geologic conditions（such as coalbed depth, thickness, structure, adja？cent rock lithology and hydrology） and gas content were researched. The results showed that gas content was increased with coalbed depths and gradually declined when it exceeded critical depth. The higher the coal rank was, the more the gas content would be. Ash content change showed poor positive correlation with gas enrichment. The more conductive the geological conditions were to be saved, the more the enrichment of coalbed methane（CBM） would be. The results provided theoretical basis for effectively develop？ment of CBM gasfield like YCN block.