基于动阻力分析的不同压力环境下圈闭含油性预测方法——以东营凹陷为例

Prediction Method of Oil-bearing of Traps under Different pressure Environment Based on Dynamic Resistance Analysis:Taking Dongying Sag as an Example

针对东营凹陷成藏压力环境复杂和不同压力环境下成藏动、阻力存在差异的情况,在分析不同成藏压力环境下成藏动、阻力的基础上,建立了基于动力学分析的不同压力环境下圈闭含油性预测方法,利用该方法对东营凹陷梁75—梁76地区沙四段滩坝砂油气成藏进行定量评价,结果表明:超压环境下,在生烃超压作用下,有效孔隙度>10%的储层含油饱和度>50%,具有大面积成藏的特点;压力过渡环境下,梁75—梁76地区的西部剩余压力差较大,是油气的有利指向区;常压环境下,油气在浮力作用下具有高点汇聚,高孔富集的特点。

The hydrocarbon accumulation pressure environment of Dongying sag is complex,and the dynamic/resistance of hydrocarbon accumulation is different under different pressure environments.Based on the analysis of the drive force and resistance of hydrocarbon accumulation under different pressure environments,a oil-bearing property prediction method of trap under different pressure environments based on dynamics analysis is established.The oil-bearing property of the beach bar sand in the fourth member of Shahejie Formation in Liang75-Liang76 area of Dongying sag is quantitatively evaluated using this method.The result shows that under overpressure environment,the oil saturation of the reservoirs whose effective porosity is higher than 10% is greater than 50%,and hydrocarbon will accumulate on a large scale in the action of hydrocarbon generation overpressure;Under the transitional pressure environment,the residual pressure difference in the western part of Liang75-Liang76 area is large,where is a favorable region for hydrocarbon accumulation;Under normal pressure environment,hydrocarbon will accumulate in the reservoir with high porosity at high position in the action of buoyancy.