准噶尔盆地南缘呼图壁南区块煤层气赋存条件分析

Analysis of Coalbed Methane Occurrence Conditions in the Southern Hutubi Block in Southern Margin of Junggar Basin

准噶尔盆地南缘呼图壁南区块作为硫磺沟煤层气富集区的毗邻区,处于煤层气勘查空白阶段,通过构造、沉积、水文地质等特征综合分析,获得以下认识:西山窑组下段为主力含煤层段,4层主力煤层空间展布稳定,属中低变质程度,含煤地层为裂隙孔隙弱含水层;西山窑组地层能够接受大气降水、冰川融水/河水的侧向补给,具有次生生物气生产条件;单斜背景条件,地表水从浅部向深部渗流,形成承压水环境,煤层气矿化度较高,有很好的煤层气吸附-聚集潜力。

The Southern Hutubi block in Junggar Basin is still in the blank stage of coalbed methane exploration.Through comprehensive analysis of tectonic,sedimentary and hydrogeologycharacteristics,the following conclusion is obtained:the lower section of Xishanyao Formation is the main coal-bearing strata,and the four main coal seams have a stable spatial distribution,which is a medium-low metamorphic degree.The coal-bearing strata belong to weak aquifers with fissures and pores.Xishanyao Formation can received the lateral recharge of the meteoric water and the glacial melting water or river water,which are of the secondary biogas production conditions.There are monoclinic background conditions,with surface water seepage from shallow to deep,forming a confined water environment.The degree of mineralization of coalbed methane is high,with a good potentialof coalbed methane adsorption-aggregation.