页岩气“压力系数”分级资源评价方法——以川东南上奥陶统五峰组—下志留统龙马溪组为例

随着我国页岩气勘探开发不断深化，亟需完善一套科学适用的页岩气资源潜力评价方法。该文重点考虑页岩气资源分布的非均质性以及保存条件的影响，在查明页岩气"压力系数"主要影响因素的基础上，将刻度区与评价区划分为A类区（压力系数大于1.2）、B类区（压力系数1.0~1.2）和C类区（压力系数0.8~1.0）。通过解剖四川盆地涪陵地区上奥陶统五峰组-下志留统龙马溪组页岩气刻度区，确定体积资源丰度作为评价区类比计算关键参数，对页岩气资源进行分级类比评价。综合计算川东南地区页岩气总资源量为5.52×1012 m3，其中埋深4 500~6 000 m的五峰组-龙马溪组页岩气资源量达4.04×1012 m3，表明该地区埋深大于4 500 m的深层具有较大的页岩气勘探潜力。

Shale gas resource evaluation based on "pressure coefficient": a case study of Upper Ordovician Wufeng-Lower Silurian Longmaxi formations in southeastern Sichuan Basin

With the continuing shale gas exploration and development in China, it is necessary to establish a scientific method to evaluate shale gas resources. This paper focuses on considering the heterogeneity of shale gas resource distribution and the impact of preservation conditions. On the basis of identifying the main influencing factors of shale gas "pressure coefficient", the study area is divided into A-type area (pressure coefficient >1.2), B-type area (pressure coefficient 1.0-1.2) and C-type area (pressure coefficient 0.8-1.0). By dissecting the shale gas calibrated area of Upper Ordovician Wufeng-Lower Silurian Longmaxi formations in Fuling, the resource volume is obtained as a key parameter for analog calculation, and the shale gas resources are evaluated by analogy. Comprehensive calculation of the total shale gas resources in the southeastern Sichuan area is 5.52×1012 m3, 4.04×1012 m3 of which is accounted for between 4 500-6 000 m depth, indicating that shale gas with a burial depth greater than 4 500 m in this area has a greater shale gas exploration potential.