东营凹陷永安镇断裂带气藏成藏规律研究

Study of gas reservoir forming law in Yong'anzhen faulted belt of Dongying sag

东营凹陷永安镇断裂带天然气藏为石油伴生气经多次运移分异聚集形成的次生气藏,其成藏因素较为复杂。为了总结天然气成藏规律,指导下步天然气勘探开发工作,对天然气成藏条件与成藏主要控制因素进行了综合研究。研究表明:充足的气源条件提供了天然气成藏的物质基础;多套储盖组合良好的配置关系构成了天然气成藏的重要地质要素;断裂作用不仅控制圈闭的形成,还为油气运移提供了运移通道和油气藏遮挡条件;温度和压力条件控制了天然气的分异,埋深小于2 000 m有利于天然气分异、聚集形成气顶气藏和纯气藏。天然气藏分布由洼陷中心到边缘呈现油藏-气顶气藏-纯气藏的分布规律。

The gas reservoirs in Yong'anzhen faulted belt of Dongying sag are secondary reservoirs accumulated via multiple migration and differentiation.The reservoir forming factors are sophisticated.This paper studies the gas reservoir forming conditions and the main control factors in order to guide gas exploration and development.The study shows that sufficient gas source had provided material basis;good configuration of multi reservoir-caprock association was an important geological element for gas reservoir forming;the faulting effect had not only controlled trap forming,but also provided migration path and barrier for oil and gas migration;temperature and pressure conditions controlled gas differentiation;the burial depth of less than 2000m was favorable for gas differentiation and accumulation of gas cap reservoir and pure gas reservoir.From central sag to the edge,the distribution of reservoirs shows the law of oil reservoir-gas cap reservoir-pure gas reservoir.