Using Well Logs Data in Logfacies Determination By Applying the Cluster Analysis technique for Khasib Formation, Amara Oil Field, South Eastern Iraq

Abstract

Reservoir facies determination is the most important job in oil industry which dominantlyrelies on the major properties of rocks. Fundamental properties of rocks are usually understoodby their detailed description in the field (lithofacies analysis) and laboratory (petrofaciesanalysis). The facies (lithofacies and petrofacies) determination in most subsurface studies isimpractical, due to lack of cores and cuttings. In such situations, where the wire line logs arethe only data available, the logfacies or electrofacies are determined instead. In this study, theavailable logs (gamma ray, density,Neutron, and sonic logs) for four wells (Am-1, Am-4, Am-5, and Am-6) were used to predicate logfacies of Khasib Formation in Amara oil field. UsingCluster Analysis in this study practiced the logfacies determination in each unit of khasibFormation in Amara oil Field using Interactive Petrophysics software. The types of input datainto Interactive Petrophysics software to determine logfacies are available logs which are usedto create 15 clusters and determine five groups of logfacies. In this paper, the verticalvariations of logfacies for Khasib Formation are carried out based on five groups of logfacies.These groups of logfacies are classified based on responses of well logs after divided KhasibFormation into three units :( upper, middle and lower Khasib). In order to estimate the ratio ofexistence of logfacies, the histogram of logfacies was built for each unit of Khasib Formationin studied wells.