鄂西鹤峰区块龙马溪组储层特征及资源潜力

Reservoir characteristics and resources potential of Longmaxi Formation in Hefeng block of Western Hubei

通过鄂西鹤峰地区地层剖面测量及露头样品采集,对龙马溪组进行了地层划分对比,并对页岩气储层表征参数进行了测试分析。结果表明,鹤峰区块龙马溪组地层可分为两段,下段地层为黑色炭硅质岩夹炭质页岩或与之互层,上段地层为含炭粉砂质页岩。龙马溪组样品TOC平均值1.63%,总体达到中等页岩气层标准,下段样品TOC值明显好于上段,炭硅质岩TOC平均值大于炭质页岩。所有样品均达到过成熟阶段,有机质类型以腐泥型为主。主要矿物为石英和粘土矿物,脆性矿物占比高。龙马溪组储层属于低孔-特低孔、特低渗储层类型。等温吸附实验测得含气量平均值1.80 m^3/t,通过体积法计算得到鹤峰区块龙马溪组页岩气吸附气资源量1541×10~8m^3。

Based on the stratigraphic profiling and the analysis of outcrop samples, the stratigraphic division and the parameters of reservoir characterization of the shale gas were analyzed.The result shows that, the Longmaxi Formation can be divided into two segments, the lower segment with the lithology of carbonaceous shale and siliceous rocks, upper segment with the main lithology of silty shale. TOC average value is 1.63% which reached medium shale gas criteria and the TOC value of lower segment is better than upper segment. Ro of all samples reached the over-mature stage and sapropel type was the main organic matter;The main mineral is quartz and clay mineral and brittleness mineral content reached high classification criteria.The Longmaxi Formation belongs to low and extremely-low porosity,extremely lowpermeability.Average gas content measured by isothermal adsorption experiment is 1.80 m^3/ t. Shale gas adsorption volume in Hefeng block is 1541×10^8m^3.