WITHDRAWN: Introducing new heterogeneity indices based on integrated petrophysical heterogeneity analysis in Sarvak carbonate reservoir of an Iranian oilfield in Dezful Embayment

Abstract

Heterogeneity is a very significant factor in reservoir static modeling, reservoir simulation, and determining hydrocarbon recovery of petroleum reservoirs. In this study, we tried to quantify and calculate different heterogeneity indicators for one cored well in the Sarvak reservoir of an Iranian oilfield located in the Dezful embayment (Zagros Basin). The coefficient of variation (CV) of permeability, Dykstra-Parsons Coefficient, and Lorenz Coefficient were used for heterogeneity analysis in the cored intervals of the formation. In addition, the coefficient of variation (CV) based on the petrophysical porosity log was calculated for whole intervals which can be used for heterogeneity index, especially in un-cored intervals. In this study, we checked the relationship between the conventional heterogeneity indices with some parameters including residual oil (Sor), variography, reservoir quality index (RQI), synthetic velocity deviation log (VDL), and skewness for the first time. This study showed that the CV of porosity can be used as reliable heterogeneity index in un-cored intervals. In addition, skewness of porosity and permeability can be used as heterogeneity indicators instead of routine static heterogeneity approaches. The existence of the shale and dolomite influences the reservoir heterogeneity. Moreover, by increasing the range of variography, CV of porosity rises. The VDL (as diagenesis indicator) and Sor have an inverse relationship with the CV of porosity. Therefore, in un-cured intervals various parameters can be used as reservoir heterogeneity indices.