Determination of rock types using hydraulic flow unit, multi-resolution graph-based clustering, and fuzzy c-mean clustering methods of the Sarvak Formation in an oilfield of Dezful Embayment

Considering the importance of the Sarvak Formation and the significant role of rock typing in reservoir quality, the purpose of this paper is to determine rock types of the Sarvak Formation by using Hydraulic Flow Units (HFUs), Multi-Resolution Graph-based Clustering (MRGC), and Fuzzy C-mean clustering (FCM) methods inside petrophysical studies with multimin method in one oilfield of north Dezful Embayment. First, using the flow zone indicator (FZI) method, 4 rock types were obtained that accordingly reservoir quality of RT4 was very good and RT1 was weak. By using MRGC, 6 electrofacies (EF) were described that reservoir quality for EF6, EF5, and EF4 was good, and their presence in parts of the formation indicates a reservoir part in the Sarvak Formation. By using the FCM method, 7 RTs were determined that according to high porosity and permeability, the reservoir quality of RT7, RT6, and RT5 are very good. The correlation of obtained data finally led to the identification of 7 reservoir zones for the Sarvak Formation. Zones 3 and 7 have the best reservoir quality, mainly studied in the middle and lower part of the formation. The correlation of the obtained data with capillary pressure curves also correlates with the identified rock types and reservoir characteristics. This study shows the high efficiency of HFUs, MRGC, and FCM methods for determining rock types at intervals non-cored in the Sarvak Formation in the studied oilfield.