吐哈盆地侏罗系煤层气资源潜力分析

Potential analysis of Jurassic coal-bed gas resources in Tuha basin

吐哈盆地是典型的低煤阶区,煤层气勘探程度较低。为了探究其煤层气地质和资源潜力,基于煤层气参数井地质资料、煤炭钻孔资料和煤岩实验测试数据,对煤岩与煤质特征、煤层厚度特征、含气性特征、煤岩吸附特征、水文地质条件和煤层顶板的岩性等条件进行了对比分析,初步估算了吐哈盆地煤层气的资源丰度和地质资源量,提出了未来煤层气勘探建议。研究结果表明:吐哈盆地侏罗系煤层分布面积广、厚度大,煤层气地质资源丰富,埋深2000 m以浅煤层气地质资源量约为1.16×10^(12) m^(3);优选沙尔湖凹陷、大南湖地区、哈密—三道岭地区为Ⅰ类有利区,艾丁湖斜坡区和托北为Ⅱ类有利区,雅满苏凹陷、七泉湖地区和科牙依凹陷为Ⅲ类有利区,其中沙尔湖由于埋藏浅、煤层厚度大、资源量较大、资源丰度最大,成为吐哈盆地最有利的勘探区块。通过对吐哈盆地煤层气有利区预测及资源量的评价,可为进一步的勘探和开发提供指导。

Tuha basin is a typical area with low rank,low exploration degree of coalbed gas,and lack of relevant research on coalbed gas geology and resource potential.Based on coalbed methane(CBM)geological and experimental parameters of well test data,through to the coal seam of Tuha basin development characteristics,the coal and rock thermal evolution regularity and maceral,coal reservoir physical properties and adsorption of coal and rock characteristics,meantime,hydrogeological condition,the lithology of coal seam roof preservation conditions and so on were analyzed,and the preliminary estimates the CBM resource abundance and geological resources of Tuha basin,put forward the suggestions for the coalbed gas exploration in the future.The study shows that the Jurassic coal seam in Tuha basin has a wide distribution area and a large thickness,and the geological resources of coal bed methane are rich.The buried depth is 2000 m,and the geological resources of shallow CBM are 1.16×10^(12) m^(3).Optimizing the Shaer lake,south lake area,Hami-sandaoling area isⅠridge area,Aidinghu lake slope area and Tuobei areas favorable forⅡclass,Yamansu jag,Qiquanhu region and Keyayi sag according to sag areas favorable forⅢclass.The Shaer lake is the most favorable exploration block in Tuha basin due to its shallow burial,large thickness of coal seam,large amount of resources and maximum abundance of resources.The prediction and evaluation of the favorable area of CBM in Tuha basin provide guidance for further exploration and development.