西峰油田合水区块长8岩性油藏流动单元划分

Flow unit classification of Chang 8 lithologic oil reservoir in Heshui District  of Xifeng Oilfield

冯杨伟 孙 卫 屈红军 高 辉 郭 真

西北大学大陆动力学国家重点实验室，陕西 西安 710069 西北大学地质学系，陕西 西安 710069 西安石油大学石油工程学院，陕西 西安 710065

State Key Laboratory of Continental Dynamics, Northwest University, Xi′an 710069, China Department of Geology, Northwest University, Xi′an 710069, China College of Petroleum Engineering, Xi′an Shiyou University, Xi′an 710065, China

针对西峰油田合水区块长8岩性油藏具有典型的低孔特低渗透与强非均质性的现状，纵向上，以岩心观察与分析和测井资料为基础，应用高分辨率层序地层学原理，对研究区长8储层进行精细的等时地层单元划分；平面上，经综合分析选取了有效厚度、孔隙度、渗透率、含油饱和度、流动带指数等5个权重参数。对这些参数应用SPSS统计分析软件进行聚类分析，将研究区流动单元划分为E类、G类、M类和P类等4类。运用判别函数对各类流动单元进行判别分析，正判率达97.2%。各流动单元的类型与储层物性、沉积微相具有很好的对应关系，流动单元微观渗流特征揭示出：E类、G类流动单元是研究区已开发程度较高的有利储层，M类流动单元是剩余油分布的富集区带，是提高采收率的关键。

Chang 8 lithologic oil reservoir in Heshui District of Xifeng Oilfield is the typical low-porosity and low-permeability reservoir with strong heterogeneity. On the basis of the analysis of core observation and well logging data, Chang 8 reservoir is classified vertically into fine isochronal stratigraphic units by applying high-resolution sequence stratigraphic theory. Through the analysis, this paper horizontally selects five weighting parameters: effective thickness, porosity, permeability, oil saturation and flow zone exponent. SPSS software is applied to cluster analysis for these pameters. The flow units can be divided into Class E, Class G, Class M and Class P. Various flow units are distinguished through the use of discriminant function and the accurate rate is 97.2%. The types of these flow units are in good accordance with the reservoir physical property and sedimentary microfacies. Microscopic percolation features of flow unit reveal that Class E and Class G flow units are the profitable reservoirs developed highly in the study area, and Class M flow unit is an enrichment zone of remaining oil, which are the key target of enhanced oil recovery.