不同级别层序界面及体系域的含油气性

Oil-bearing degree of different-scale sequence boundaries and system tracks

将济阳坳陷不同级别的层序边界及层序内各体系域发育的储集层与油气探明储量的关系进行对比 ,发现处于主要烃源层之上的低频层序的低位体系域中发育的砂砾岩储集层油气储量最多 ,中频层序的低位体系域发育的储集层油气储量中等 ,高频层序的低位体系域中发育的储集层油气储量最少。湖侵体系域中油气储集层相对不发育 ,油气储量较少。河流相层序高位域发育的储集层呈透镜状 ,封闭性好 ,因此含油性好。湖泊相层序高位域的三角洲相进积式准层序组和准层序边界对油气封闭性的影响取决于后期的构造变动 ,后期构造活动不影响低位域储集层的含油气性 ,但通过改造高位域原始层序地层几何形态和倾向 ,可以大大增加高位域储集层的封闭性 ,从而提高其含油气性。图 4表 1参

On comparison of the found oil and gas reserves with the different scale sequence boundaries and reservoirs in system tracks in the Jiyang Depression, it is found that the reserves of oil and gas in glutenite reservoirs of low frequency sequence are real huge, and those in glutenite reservoirs of medium frequency sequence are in the medium, and those in glutenite reservoirs of high frequency sequence are minimum. In transgresssive system tracks, oil and gas reservoirs developed not well, and the oil and gas reserves in them are very small. In fluvial highstand system tracks, the shape of the reservoirs is lenticular, with good sealing conditions, so the reserves of oil and gas in this kind of reservoir are great. In lacustrine highstand system tracks, the effects of progradational parasequence sets and para sequence boundaries of delta facies on the trapping of oil and gas depend on subsequent tectonic movements. The subsequent tectonic movements did not influence the oil bearing degree of reservoirs in lowstand tracks, but could strongly increase sealing capability of reservoir in highstand tracks through changing original geometric configuration and trend of sequence strata, and then improved oil bearing degree.