Determination of electrofacies using wireline logs based on multivariate statistical analysis for the Kareem Formation, Gulf of Suez, Egypt

Abstract

Beyond the traditional use of well logs, electrofacies were introduced to define a set of log responses that can be used to characterize a bed and permitted it to be distinguished from the other rock units. Classification of a formation into electrofacies can be used in reservoir characterization and discrimination. Due to the hydrocarbon potential of the Kareem Formation, we used the conventional well logs of four boreholes and a traditional core analyses data from one of these wells to identify electrofacies of the Kareem Formation in the Southern Gulf of Suez. Multivariate statistical analyses, such as principal component analysis ‘PCA’ and cluster analysis, were used for this purpose. The multivariate statistical analyses were applied to the raw log data, the normalized data and the standardized log data. Three PC components were obtained from the analyses, and six distinctive electrofacies were extracted from the dendrogram plot. These electrofacies showed good correlation with the lithofacies that were described from core analysis. In addition, applying the reservoir zonation of the studied formation using the stratigraphic modified Lorenz ‘SML’ plot and the sum of squared errors ‘SSE’ methods led to its discrimination into four hydraulic flow units. The deduced flow units were validated against the available core data.