惠民凹陷商河油田商一区沙二下亚段储层非均质性研究

Research on Reservoir Heterogeneity of Lower Member of Es2 in the First Block of Shanghe Oilfield in Huimin Sag

通过岩心精细观察描述、岩石薄片观察、扫描电镜分析等方法,结合储层物性测试资料以及测井资料综合解释结果,对商河油田一区沙二下亚段储层开展非均质性分析及其控制因素研究。结果表明:① 储层发育正韵律、反韵律和复合韵律三种韵律模式,层内夹层较发育,以泥质夹层、钙质夹层为主,横向稳定性较差,储层层内非均质较强;小层间渗透率最大差异可达87 ×10?3 µm2,综合比较各单砂层渗透率、隔层发育规模等的差异,认为研究区层间非均质性较强;② 砂体形态主要受控于沉积微相,储层物性与沉积微相有较好的相关关系,水下分流河道和河口坝主体砂体厚度大,平面连续性好,物性最好,其平面非均质性较弱;向河道侧翼及坝体边缘储层厚度减薄,泥质夹层增多,储层物性变差,平面上非均质性较强;③ 沉积环境是影响研究区储层非均质性的根本原因,控制了砂体的发育规模及展布状态,并对储层物性起决定作用,压实、胶结及溶蚀等成岩作用导致储层的孔渗等发生不均一的次生变化,进一步加剧了储层的非均质性。

By means of detailed observation and description of core,thin section observation,scanning electron microscope analysis and other methods,combined with reservoir physical property test data and comprehensive interpretation results of logging data,heterogeneity analysis and control factors of the reservoir in the lower member of Es2 in the first block of Shanghe oilfield were studied.The results showed that:①positive rhythm,negative rhythm and compound rhythm were developed in the reservoir,and the interlayer was well developed.The shale interlayer and calcium interlayer were the main interlayers,and the lateral stability was poor.The maximum difference of permeability between small layers can be up to 87×10?3µm2.Based on the comprehensive comparison of the differences in permeability and development scale of individual sand layers,it is concluded that the interlayer heterogeneity is strong in the study area.②sand body morphology is mainly controlled by sedimentary microfacies,and the reservoir physical properties and sedimentary microfacies have a good correlation.The main body of underwater distributary channel and the estuary dam were much thicker with good plane continuity and the best physical properties,and for this part,the plane heterogeneity is weak;to the side of the channel and the edge of the dam,the thickness of the reservoir decreases,and the number of shale interlayers increases,and the physical properties of the reservoir become worse.③sedimentary environment is the root cause affecting the reservoir heterogeneity in the study area.It controls the development scale and distribution state of the sand body,and plays a decisive role in the reservoir physical property.Diagenesis,such as compaction,cementation and dissolution,leads to uneven secondary changes in the pore and permeability of the reservoir,which further aggravates the heterogeneity of the reservoir.