Sedimentary Facies and Depositional Stratigraphy of Pazanan Oil-field Sedimentary Facies and Depositional Stratigraphy of Pazanan Oil-field

Early understanding of the reservoir performance and sweet areas can make a huge economical change in the development decisions. The role of geologist is to prepare a description of the reservoir properties which are controlling the flow and storage mechanisms of the rock. On the basis of geological models, the reservoir engineers can build the reservoir models to optimize the well production and predict the performance of the wells. The focus of this study is to characterize Pazanan oil field of Asmari formation in Iran based on the data gathered through well logs, microfacies and mineralogical tests. The geological distribution of reservoir properties is mapped and the result is used in simulation studies to determine an economic recovery plan. Asmari Formation in Zagros Basin is a carbonate reservoir that is usually heterogeneous in different depths. Therefore, it is critically needed to fully characterize the reservoir before making any decision about the appropriate depth for well placement. The main objectives of this paper are to (1) recognize the depositional environments represented by the Asmari Formation and (2) use the advanced characterization tools such as electrical facies to describe the petro-physical properties of the formation. The results of the study show that, based on log data and supportive mineralogical and microfacies studies, the Asmari formation can be subdivided into several microfacies that are distinguished based on their depositional textures and petrographic analysis. The simulation study also suggests that the performance of an imaginary well is quite different if one ignore the serious heterogeneity of the reservoir.