三塘湖盆地流体包裹体研究及其应用

Application of fluid inclusion to study of petroleum migration in Santanghu basin,China

通过镜下观察,并对流体包裹体岩相学特征、不同包裹体组合特征和显微测温等方面进行分析,可以确定不同产状内包裹体形成的先后关系,同时依据烃类包裹体特征可以分析储层的烃类组成、烃类充注史、古流体压力和古流体势。根据三塘湖盆地包裹体岩相学特征、组合类型以及与烃类包裹体伴生盐水包裹体的均一温度,不同微裂隙内的包裹体按照其产状可分为两类:网状微裂隙内捕获的包裹体和单向微裂隙内捕获的包裹体。根据不同产状内的包裹体特征,分析得出它们是由不同流体来源在不同时期捕获的。根据古地温演化趋势图,通过测温数据推算三塘湖盆地条湖凹陷内大量烃类包裹体被捕获的时间在晚侏罗世,马朗凹陷内大量烃类包裹体被捕获的时间在晚白垩世。在计算包裹体流体势基础上做出古流体势图,显示各凹陷的北部较利于油气聚集,预测位于油气运聚路线上的马中构造带是有利油气聚集区。

The fluid inclusion petrographic, association types and microthermometric data are important to acquire the chronology of aqueous and oil-bearing through the microscopy. The analysis of fluid inclusions can be used to evaluate oil compositions, migration timing, trap-fill history, paleo-pressure and paleo fluid potential in petroleum reservoirs. According to the kinds, association types and homogenization temperatures of different microcracks, the diagenesis fluid inclusions can be divided into two types： the fluid inclusions in reticulate microcrack and in unique microcrack. These different characteristics suggest that fluid inclusions in reticulate microcrack and unique microcrack were probably trapped in two or more types of geothermal fluids in different time. Depending on the trendline of geothermal history, the hydrocarbon inclusions in Jurassic reservoir of Tiaohu sag and of the Malang sag in Santanghu basin were trapped at late Jurassic and at late Cretaceous separately. Calculate the fluid potential and draw the fluid potential dynamic maps, which preliminary show the north sags are the vantage points and The Mazhong tectonic belt is advantageous to oil and gas accumulation.