泥岩盖层烃类垂向分布规律和气藏追索

在总结盖层烃类分布特征的基础上,用油气地球化学理论和盖层封油气理论,分析了盖层内烃类垂向分布的成因机制.盖层内烃类由“残留烃”和“滞留烃”叠加而成,残留烃主要分布于盖层中部,其组成变化受盖层排烃效应的控制,滞留烃主要分布于盖层的下部,其组成变化受烃类垂向迁移效应的控制.建立了盖层烃类垂向分布成因模式.并探讨了盖层烃类垂向分布规律在盖层研究和气藏追索中的作用.

VERTICAL DISTRIBUTION REGULARITIES OF HYDROCARBON IN SHALE CAP ROCK IN RELATION TO SEARCHING FOR GAS RESERVOIRS

On the basis of summing up the features of hydrocarbon distribution in cap rock,the genetic mechanism of hydrocarbon vertical distribution in cap rock is analyzed by applying hydrocarbon geochemistry theories and also theories regarding hydrocarbons sealed by cap rock. The hydrocarbons in cap rock are composed of "residual hydrocarbons"and "occluded hydrocarbons", which stack each other.The residual hydrocarbons mainly distribute in the middle part of cap rock with hydrocarbon composition variation controlled by the effect of cap rocks to expell hydrocarbons;while the occluded hydrocarbons mainly distribute in the lower part of cap rock with hydrocarbon composition variation controlled by the effect of vertical migration of hydrocarbons.The genetic model of hydrocarbon vertical distribution in caprock is established.Also discussed is the role which can be played by the regularities of hydrocarbon vertical distribution in cap rock in studies on cap rock and searching of gas reservoirs.