湘中坳陷上泥盆统锡矿山组页岩气成藏条件及资源量预测

Resources Prediction and Accumulation Conditions of Shale Gas of Xikuangshan Formation of Upper Devonian in Middle Hunan Depression

在野外地质露头观察和样品测试数据综合分析的基础上,对湘中坳陷上泥盆统暗色泥页岩的厚度与区域分布、有机质丰度、成熟度以及储层矿物学特征、烃源岩热演化史等页岩气藏形成条件与沉积环境进行了研究。该区由北向南依次发育三角洲相、碎屑岩潮坪相及潟湖相等沉积相带;暗色泥页岩的厚度较大且区域分布广泛,呈现北厚南薄的趋势;页岩总有机碳含量高,有机质以高成熟与过成熟为主,储层物性好,脆性矿物含量高,游离气含量高,烃源岩正处于高热演化期;应用体积法预测出湘中坳陷泥盆统锡矿山组总资源量为(0.219~0.420)×10^(12) m^3。

Based on comprehensive analysis of outcrops observation and sample testing data of Xikuangshan formation of Upper Devonian,to analysis accumulative conditions of shale gas and sedimentary environment in the area,such as regional distribution,contents of organic maturity,reservoir mineralogical characteristics,burial history of the dark shale.The sedimentary facies zones developed in the depression include delta facies,tidal-flat facies and lagoon facies distributed from the north to the south.Shale occurred widely and distributed stably in the area,which becomes gradually thinner from the north to the south.The shale has high total organic carbon(TOC),high organic matter maturity,good physical property of reservoir,high brittle mineral content,high content of free gas.It was supposed that the hydrocarbon source rock in the higher mature.The volumetric method applied for predicting the resource,the total quantity was(0.219~0.420)×10^(12) m^3.