高邮凹陷北斜坡阜三段砂体展布及油气运移特征

Sand-body distribution of the E_1f_3 member and its relationship with hydrocarbon migration in the northern slope of Gaoyou sag

高邮凹陷北斜坡阜三段储层发育不均,油气运移路径复杂。通过细分砂层组,开展精细沉积微相研究,并结合大量油气显示资料综合分析了砂体展布及油气运移路径。结果表明,研究区阜三段各砂层组发育3——5支三角洲前缘水下分支河道,水下分支河道和河口坝微相砂体物性较好,其展布控制着优质储层的分布。油气运移路径在内、外坡带差异明显,在内坡带,油气运移受控于水下分支河道砂体的展布;在外坡带,油气运移则受构造和水下分支河道砂体的双重控制。因此,在内、外坡带须采取不同的勘探策略。

The E1f3 member is featured by serious reservoir heterogeneity and complex hydrocarbon migration pathways. Based on the study of sedimentary microfacies and stratigraphic correlation of the sand sets, we analyze comprehensively the hydrocarbon migration pathway by integrating oil and gas show of drilling data in this paper. The result indicates that there are 3-5 subaqueous distributary channels in every sand subset in the north slope of Gaoyou sag, and the study shows that the subaqueous distributary channel and channel-mouth bar are more available for the reservoir property, and its sand-body distribution controls the spread of the high quality reservoir. Further analysis reveals that the hydrocarbon migration pathways are different between the inner and the outer slope. In the inner slope, the hydrocarbon migration pathways are influenced by the distribution of subaqueous distributary channel, and in the outer slope, the hydrocarbon migration pathways are controlled by both the tectonic zone and the sand-body distribution. So, different prospecting tactics in the inner and the outer slope should be considered.