页岩气资源评价方法及应用——以焦石坝地区五峰组—龙马溪组为例

为了明确涪陵页岩气田焦石坝区块五峰组—龙马溪组上部气层地质资源量,评价区块资源潜力,针对涪陵页岩气田焦石坝地区勘探程度较高、钻井资料较为齐全的基础条件,利用区内已钻探7口评价导眼井资料,选取静态法对该区块五峰组—龙马溪组上部气层页岩气资源量进行计算,根据地质行业标准《页岩气资源/储量计算与评价技术规范》要求,游离气地质资源量计算采用容积法,吸附气地质资源量计算采用体积法,重点阐述计算方法及所需的各项参数,包括面积、厚度、总孔隙度、游离气含气饱和度、吸附气含量等,初步计算了涪陵页岩气田焦石坝地区五峰组—龙马溪组上部气层资源量约为1 100亿m³,资源丰度大于4亿m³/km²,页岩气资源量评级为Ⅱ级,具备较好的开发潜力。采用该方法对涪陵页岩气田焦石坝区块进行资源量计算和评价,获得了地质资源量,评价了区块产气效果,方法应用适应性较好,是开展焦石坝区块页岩气储量动用状况研究的重要基础。

Shale gas resource evaluation method and application: An example of Wufeng Formation-Longmaxi Formation in Jiaoshiba area

In order to determine the geological resource of the upper gas reservoir of Wufeng Formation-Longmaxi Formation in Jiaoshiba block of Fuling shale gas field and evaluate the resource potential of the block, based on the high degree of exploration and the complete drilling data, the authors utilized the data of seven evaluation and horizontal wells to calculate the shale gas resource in upper gas layer of Wufeng Formation - Longmaxi Formation of the block by the static method. According to the requirement of geological industry standard Regulation of Shale Gas Resources/Reserves Estimation, the capacity method was used to calculate the geological resource of free gas, and the geological resource of absorbed gas was calculated by volume method. The authors explained emphatically the calculation method and various parameters, including the area, thickness, total porosity, free gas saturation, absorbed gas content, etc. The geological resource of the upper gas reservoir of Wufeng Formation-Longmaxi Formation in Jiaoshiba block of Fuling shale gas field was preliminary calculated. The results show that the geological resource is about 110 billion m³, and the resource abundance is about 0.4 billion m³/km². The grade of the shale gas resources is II-class, and there is a good development potential in the study area. This method is used to calculate and evaluate the resources of the Jiaoshiba block in Fuling shale gas field. The geological resource is obtained and the effect of the block is evaluated. The application of this method has good adaptability. This research is an important basis for the study of shale gas reserves producing situation in Jiaoshiba block.