流体包裹体在古压力模拟研究中的应用

APPLICATION OF FLUID INCLUSION IN PALAEOPRESSURE MODELLING RESEARCH

烃类流体包裹体的最小捕获压力可以通过其在PT空间投影的等容线单值变化和等容线的物理特性来确定。南海琼东南盆地YC2 11构造崖城组砂岩中的方解石脉、石英次生加大边和颗粒裂纹中的流体包裹体反映 ,地史时期该区曾经发育过 4期流体包裹体 ,盖层在第三期热流体活动时期 ,曾发生过破裂 ,但稍后又快速愈合 ,从而未形成大量游离型天然气藏。

The minimum trapping pressure ratio of hydrocarbon fluid inclusions can be defined by their isochore single value variations in P-T space projection and physical property of their isochore. Calcite veins, quartz secondary enlarged margins and fluid inclusions in particle cracks in sandstones of Yancheng Formation of YC21-1 structure in Qiongdongnan(southeastern Hainan) basin of the South China Sea indicate in geologic history that four phases of fluid inclusions were developed in that region; the capping bed was once burst during the third mobile phase of thermo-fluid inclusions which would be healed soon after. Therefore, no many free-state natural gas reservoirs could be formed there.