关键词: 砂岩, 成岩作用, 八道湾组, 柯柯亚构造, 台北凹陷

Abstract:

Deep gas reservoirs usually situate at the bottomor the side slope of a syncline. The main feature of deep gas reservoirs is the inversion of gas and water distribution. Actually the deep gas reservoir is not a scientific concept, and the inversion of gas and water can not happen at all. According to the study, the gas and water in a huge container can not be inverted, and gravity separation can make gas and water distribute normally. The gas and water in a uniform capillary can not be inverted, and buoyancy can move the gas upward. The gas and water in a funnel-shape capillary can also not be inverted because there is a stronger driving force tomove gas upward. The inverse funnel-shape capillary can stop the further move of gas upward with the sealing of capillary pressure and make the gas accumulate. In the caprock of conventional structural gas reservoirs and in the surrounding rocks of lithologic reservoirs, there is formation water, but it is not inverted with the gas in the reservoirs. Due to heterogeneity, the traps of physical property form in sandstone formations and the traps of physical property can be anywhere of a formation, but it may not necessarily stay on the top of a structure. The trap of physical property proposed is a scientific concept, and it can replace the deep gas trap and serve the oil and gas exploration better.

Key words: sandstone, diagenesis, Badaowan Formation, Kekeya structure, Taibei sag