济阳坳陷天然气成藏主控因素分析

PRIMARY FACTORS CONTROLLING GAS RESERVOIR FORMING IN JIYANG DEPRESSION

济阳坳陷天然气资源十分丰富,控制天然气成藏的地质因素主要有气源、储层、温度、压力、断层与不整合面、区域盖层和直接盖层等。文中详细阐述了各项因素在天然气成藏过程中的控制作用,指出了不同母质类型,不同热演化阶段的烃源岩,对天然气成因类型与气藏性质的影响。储层是控制气藏规模大小的主要因素之一。低地饱压差是形成气顶气藏或纯气藏的必要条件。断层与不整合面不仅是天然气的主要运移通道,也是各类圈闭聚集天然气的重要因素。对济阳坳陷封盖天然气的区域盖层和直接盖层做出了微观定量评价。

The resource of natural gas in Jiyang Depression is abundant. The primary factors controlling gas reservoir forming include gas source, reservoir, temperature, pressure, fault, unconformable surface , regional cap and direct cap. This paper analyzes the roles of the main controlling factors in forming of gas reservoir and indicates that rock source in different type of gas source and different thermal evolution affects the type of natural gas and the character of gas reservoir . The reservoir is the one of controlling factors which determines the scale of the gas reservoir. The lower dispersion between the reservoir pressure and the saturation pressure is essential in forming pure gas reservoir or gas cap reservoir. Fault and unconformable surface are not only the migration passage of gas, but also the component of gas trap. The paper provides quantitative evaluation for regional cap and direct cap sealing the nature gas in Jiyang depression .