吐哈盆地沙尔湖凹陷侏罗系煤层气勘探新认识

为了探讨吐哈盆地沙尔湖凹陷侏罗系煤层气的勘探潜力,应用大量最新分析化验数据和钻井资料,分析了煤层发育特征、煤岩热演化规律和显微组分、煤储层物性、煤层气成因类型、煤岩吸附特征、含气性、构造运动、水动力条件、煤岩直接顶板的岩性等保存条件及前期煤层气井勘探失利原因等。结果表明,沙尔湖凹陷煤岩热演化程度低,具典型的煤层原生生物气特征,均质性差;但煤层厚度大,煤层裂隙及大孔发育,原煤含气量高,煤层气保存条件较好,煤层气总资源量较大。总之,沙尔湖凹陷侏罗系煤层气成藏条件优越,资源丰度高,采用合适的钻井、完井、储层改造措施及排采制度,将会取得一定的勘探成效。

A new understanding of exploration of Coalbed Methane in Sha"erhu Sag

In order to discussion the exploration potential of Jurassic Coalbed methane in the Sha"erhu Sag of Tuha Basin a lots of new testing data and drilling data were used to analysis the Jurassic coalbed distribution,coal rock thermal evolution,maceral content,coal reservoir physical properties,coal bed gas genetic types,coal adsorption characteristics,containing gas,Tectonic movement,The hydrodynamic condition, the preservation condition of the direct roof lithology as well as the reason of CBM well exploration failure. As the results show,in Sha"erhu Sag coal rock thermal evolution degree is low, with typical characteristics of biogas, poor homogeneity; but coal seam is thick,coal fracture and large pores develop well, raw coal gas content is high,the preservation condition of coal seam gas is better,coal seam gas resource amount is larger. Therefore,Jurassic Coalbed methane forming conditions in Sha"erhu Sag is superior, resource abundance is higher. Using proper drilling, completion, reservoir reconstruction measures and drainage system will have a certain exploration and development potential.