Geostatistical Lithofacies Modeling of Carbonate-Evaporite Succession -Kangan Formation-Based on Variography Analysis and Sequential Indicator Simulation Method in One of the Hydrocarbon Fields of Persian Gulf

Lithofacies investigation has an important role in hydrocarbon exploration and development stage. Several methods and studies have been done about reservoir properties based on geostatistical knowledge in hydrocarbon fields up to now, but some limited studies have been done about lithofacies propagation and modeling. In this study, data from 21 wells (petrophysical logs, cutting and core) in one of the hydrocarbon fields in Persian Gulf have been investigated. In the studied field, the Carbonate-Evaporate Kangan succession has been divided in two zones (A and B) and six sub zones (a1-a2-a3 and b1-b2-b3) based on petrophysical evidences and indications from cutting. For modeling lithofacies, six lithofacies codes have been presented; the codes are as folllows: anhydrite, limestone, dolomite, shale, dolomitic limestone, dolomite with anhydrite. After variography analysis, identified codes have been propagated based on sequential indicator simulation method by considering depositional environment of Kangan Formation (Early Triassic) in the studied area. The results of this study which have been confirmed by new drilling wells data, show that this method has a good accuracy and can be used in related sequences to predict the lithofacies and good reservoir properties.