二连盆地群低煤阶煤层气成藏模式——以霍林河盆地为例

为了建立断陷盆地的低煤阶煤层气成藏模式,从二连盆地群的霍林河盆地地质条件与煤层气地质特征入手,探讨该类盆地煤层气富集规律。研究结果显示:霍林河盆地煤层厚度可达80 m,煤层含气量为1.6~5.62 m³/t,瓦斯风化带深度为450~500 m;煤层的分布特征受同沉积构造与沉积环境控制,盆地内部小型凹陷与隆起决定着煤层的发育位置和煤层埋藏深度,基底的整体抬升确定了瓦斯风化带的位置;翁能花向斜与西南部向斜处,煤层厚度和埋藏深度均较大,煤层顶底板岩性为泥岩,其受到后期构造影响小,是煤层气成藏的有利地带。

Coalbed methane reservoir-forming pattern of low rank coal in Erlian basin:with Huolinhe basin as an example

To establish coal bed methane reservoir-forming pattern of low coal rank faulted basin,this paper studied geological conditions and CBM geological features in Huolinhe basin to get CBM enrichment regularity.It was concluded that in Huolinhe basin coal seam thickness is 80 meters and coal bed gas content is between 1.6～5.62 m3/t.Coal bed methane weathering line is about 450～500 meters deep.Distribution of coal is controlled by contemporaneous structure and sedimentary environments.Inner basin,the small depressions and uplifts decided the location of coal seam development and affected the burial depth of coal seams.The overall uplifting of the basement determined the location of gas weathered zone.In the middle of Wengnenghua syncline and south-west syncline,coal seam is favorable to coal bed methane reservoir,because of big thickness of coal seam,appropriate buried depth of coal seams,roof and floor lithology of mudstone and being little affected by later tectonic.