川西北地区须家河组二段储层中包裹体流体势研究

A study of paleo-fluid potential from inclusions in the 2 member of Xujiahe Formation in northwestern Sichuan

许浩 汤达祯 魏国齐 吴世祥 张君峰

Xu Hao Tang Dazhen Wei Guoqi Wu Shixiang Zhang Junfeng

有机包裹体的岩石学、热力学特征以及组成成分的对比分析表明,川西北地区须家河组二段储层中的包裹体可划分为4个期次,分别形成于三叠纪末到沙溪庙期、晚侏罗世中-晚期到早白垩世早期、早白垩世至喜山期前及喜山期后,代表了4次油气的充注过程。应用流体包裹体的分析资料,可获得包裹体被捕获时的古高程、密度、压力等基础数据。依照这些数据可求得古流体势,使用这一方法计算了川西北地区须家河组二段的古流体场,结果表明,燕山期区域流体场明显经历了变动-调整-再变动-再调整的历史演化过程。

Comparative analyses of petrology,thermodynamic characteristics and components of inclusions in the 2 member of Xujiahe Formation in northwestern Sichuan show that the inclusions had been formed in 4 different stages,i.e.in Late Triassic to Shaximiao age,middle-late Late Jurassic to early Early Cretaceous,Early Cretaceous to pre-Himalayan, and post-Himalayan, respectively,which represent 4 hydrocarbon charging processes.Analysis of the fluid inclusions can reveal paleo-elevation-density and-pressure when the inclusions were entrapped.These data can be used to calculate the fossil fluid potential.This method has been used to calculate the fossil fluid field of the 2 ndmember of Xujiahe Formation in northwestern Sichuan.The results show that regional fluid field obviously has gone through an evolution process of variation adjustment revariation-readjustment.

10.11743/ogg20040520