砂岩对热流体作用的响应及识别标记——以珠江口盆地西部为例

The responses of sandstone to hot fluid flow and their identified markers—A case study from the western part of the Pearl River Mouth Basin

沉积盆地中流体的作用越来越受到人们的关注,在整个地球范围内研究流体与岩石、流体与流体的相互作用是地学界当前乃至今后重要的课题。砂岩因其发育孔隙为流体的流动和流体与岩石的相互作用提供了场所。地表以下较深处形成的热流体运移到较浅部时,与“冷”砂岩之间存在着温度、成分等多方面的差异,两者之间必然发生化学反应。通过研究砂岩的物质成分,砂岩的格架颗粒的蚀变现象,新生胶结物矿物的形成,储层砂岩孔隙度在垂向上的变化,碳酸盐矿物、石英次生加大边和石英裂隙中的包裹体温度以及镜质体反射率的变化情况追踪砂岩对热流体作用的响应标记,同时探讨了砂岩与热流体作用的机理,为进一步研究油气运移与砂岩储层的质量及储层预测有理论意义和实践意义。

Fluid flow in sedimentary basins is a noteworthy subject in the field of geology. The interaction of fluid flow with rocks or with other fluid flow in the earth is an extremely important subject for recent and future studies. Sandstones, which are porous and permeable, can provide the reaction space for fluid flow and rock interaction. When fluid flows generated in the deep crust migrate into shallower crustal levels, there must be a potential of chemical reaction between the hot fluid flow and “cold” sandstone because they have different temperatures and compositions. This study traces the processes of hot fluid flow interactions with .sandstone through the study of .sandstone constituents, alteration of skeletal mineral grains, neo-cement minerals, vertical variation of porosity of sandstone, inclusion temperatures, and vitrinite reflectance. We also discuss the mechanisms of interaction of hot fluid flow with .sandstone. This study is significant both in thcory and in practice for further study of the migration of oil and gas, the quality of petroleum reservoirs, and for reservoir exploration.