湘西北地区震旦纪陡山陀组页岩气储层特征

对湘西北下震旦统陡山陀组页岩气有利层位进行相应的地球化学、物性特性分析,并结合地质保存条件等因素对含气页岩层进行了综合评价,得到区内页岩主要物化指数:TOC为0.52%~6.79%,均值为2.25%;Ro为2.38%~2.87%,均值为2.56%,干酪根类型为Ⅰ型;孔隙度为0.6%~8.7%,平均为3.9%,渗透率均小于0.04×10-3μm2,属低孔低渗类型。页岩埋深主要在2000~5000m,且有效厚度基本大于20m,具有页岩气成藏条件,页岩气勘探开发前景良好。

Shale Gas Reservoir Characteristics in Sinian Doushantuo Formation,Northwestern Hunan

Corresponding geochemical, physical property analyses have been carried out for favorable shale gas horizons in lower Sinian Doushantuo Formation in northwestern Hunan. The comprehensive evaluation on gas-bearing shale strata combined with factors includ-ing geological hosting condition has gotten main physical and chemical indices as follows： TOC 0.52%-6.79%, average 2.25%; Ro 2.38%-2.87%, average 2.56%;kerogen type I;porosity 0.6%-8.7%, average 3.9%;permeability all less than 0.04×10^-3μm^2, thus be-longs to low porosity, permeability type. Buried depth of shale strata is mainly within 2 000~5 000m, effective thickness basically larger than 20m thus provided with shale gas reservoiring condition, and excellent shale gas exploration and exploitation prospect.