济阳坳陷永921地区沙四段可容空间变化速率与储层特征的关系

济阳坳陷永 92 1地区沙四段储层第Ⅳ油层组与第Ⅴ油层组具有相同的沉积微相 ,近似相同的埋深和构造位置 ,但其储层物性差异较大。第Ⅳ油层组储层物性差 ,非均质性强 ,含油性也差 ;第Ⅴ油层组储层连通性好 ,储层物性好 ,含油性也好。通过分析由构造因素所控制的可容空间的变化发现 ,第Ⅴ油层组沉积时期 ,可容空间的生长速率低 ,沉积物可以得到充分的分选 ,砂砾岩得以沉积 ,泥岩及杂基被进一步搬运到盆地中心沉积 ,因而其储层物性很好 ;第Ⅳ油层组沉积时期 ,可容空间的生长速率高 ,单位时间内有足够的空间接受几乎所有搬运来的沉积物的沉积 ,沉积物得不到充分的分选 ,砂砾岩、泥岩及杂基同时沉积 ,因而其储层物性很差。

Relationship between reservoir quality and creative accommodation rate in the fourth member of Shahejie formation of lower tertiary in Yong 921 area of Jiyang depression

In Yong 921 area of Jiyang depression, the sedimentary microfacies, burial depth and the structures of para sequence set 4 are similar with those of para sequence set 5, but the reservoir properties of the two sets are very different. The reservoir properties of para sequence set 4 are bad, but its heterogeneity is very strong, and the oil saturation is also very heterogeneous. The connection ratio of reservoir in para sequence set 5 is very high, its reservoir properties are good, and the oil saturation is very high. The analysis on the creation rate of accommodation controlled by tectonic movement shows that the creative accommodation rate was very low during the sedimentation of para sequence set 5. The sediments could be graded thoroughly. Only sand and conglomerate were sedimented, and mud and matrix were migrated and sedimented in the basin. So the reservoir properties were very good. During the sedimentation of para sequence set 4, the creative accommodation rate was very high, and there was enough accommodation to accept all the sediments transported from far away. The sediments could not be graded thoroughly. The sand, conglomerate, mud and matrix could be sedimented at the same time, so the reservoir properties were very bad.