湖北及周缘五峰组—龙马溪组页岩气资源潜力

Shale Gas Resource Potential of Wufeng- Longmaxi Formationsin Hubei and Its Periphery

奥陶世五峰期—志留世龙马溪期湖北地区处于浅海陆棚环境中,以泥页岩沉积为主。类比分析认为,该套泥页岩层与北美页岩气高产层具有相似的构造演化和地质条件,具备形成页岩气聚集的有利条件。分析研究区页岩气成藏条件,提出页岩气勘探有利区的优选原则,结合TOC、镜质体反射率、有效厚度与埋深等值线图交集结果以及沉积相平面展布,优选勘探有利区块。采用体积丰度类比法计算有利区资源量,初步估算五峰组—龙马溪组页岩气资源量为2.48×1012m3,显示出该区巨大的资源潜力。

Ordovician Wufeng- Silurian Longmaxi formations in Hubei were developed in shallow shelf environment with shale as its dominant deposition. Analogy analysis presents that the tectonic evolution and geology of this shale set is similar to that of the high- production shale sets in North America,and it is favorable to shale gas accumulation. The shale gas accumulation conditions of this area were analyzed and the selection principles of favorable zones were proposed. Favorable zones were selected by using TOC content,vitrinite reflectance,crossplot between contours of net thickness and buried depth and plane distribution of sedimentary facies. Volume abundance analogy was used to calculate the resources of favorable zones. According to the preliminary estimation,the shale gas resources of Wufeng- Longmaxi formations are 2. 48 × 10^(12)m^3,which indicates huge resource potential in this area.