二连盆地巴彦宝力格煤田褐煤煤层气资源潜力预测

摘要

为了对低含气量、厚煤层的褐煤区进行煤层气勘探,圈定煤层气有利区,以煤层气勘探程度较低的二连盆地巴彦宝力格煤田为研究对象,通过煤岩工业分析、显微组分以及煤相、含气量、储层、构造、盖层及水文地质等方面的研究,对该煤田煤层气地质条件进行初步评价,预测勘探开发潜力区.研究表明:该煤田含煤地层为下白垩统巴彦花群赛罕塔拉组二岩段(K1bs2),腐质组反射率平均约0.299％,属于年轻褐煤,显微组分以腐质组为主,其中2煤、3煤厚度均较大,平均厚度分别为13.21 m和7.8 m,区域展布面积广,煤层结构简单,稳定性高,有利于煤层气的生成和保存,且直接盖层主要以厚层泥岩为主,最厚可达231.75 m,为煤层气提供了良好的封闭环境.综合煤层气成藏地质条件,固定了巴彦宝力格煤田中部及东北部为褐煤煤层气勘探开发潜力区.%In order to make the coalbed methane(CBM) exploration in a low gas content and thick seam of the lignite area,a favorable coalbed methane area was targeted.The Bayan Baolige Coalfield with a low coalbed methane exploration degree in Erlian Basin was taken as the study object.With the study on the proximate analysis of the coal and rock,maceral and coal facies,gas content,reservoirs,structures,caprock,hydrogeology and other aspects,a preliminary evaluation was conducted on the geological conditions of the coalbed methane in the coalfield and the exploration and development potential area was predicted.The study showed that the coal measures in the coalfield were the second rock section (K1bs2) of Bayan Huaqun Saihan Tala Group in the lower Cretaceous.The reflectivity of the humus formation was about 0.299％ in average and was the youth lignite.The maceral would be the humus group mainly.The thickness of No.2 seam and No.3 seam would be thicker in average and the average thickness would be 13.21 m and 7.8 m individually.The distribution area in the region was wide,the coal structure was simple and the stability was high in favorable to the coalbed methane formation and reserving.The direct caprock would be a thick mudstone mainly and the max thickness would be 231.75 m in order to provide a good sealed environment to the coalbed methane,In combination with the deposition geological condition of the coalbed methane,the central part and the north-east part of Bayan Baolige Coalfield were targeted as the coalbed methane exploration and development potential areas of the lignite seam.