Sedimentological studies and Petrophysical interpretation: An approach to reservoir characterization of Sarvak formation in the Dalpari oil field

The Ilam and Sarvak Formations of Bangestan Grouop are the second important potential reservoirs after Asmari formation in the zagros basin. Integration of petrographical factors and Petrophysical parameters resulted in better understanding of reservoir qualities of these formations. In this study، 250 thin sections were collected and subjected to microfacies and petrography studies. As a result eight microfacies from three sedimentary environments were identified: Lagoonal (L، L، L3)، Barrier (B1، B2) and Open marine (O1، O2، O3) and in three different of digenetic environments such as marine، meteoric and burial. This Study shows Sarvak Formation is being formed on Carbonate Rimmed shelf platform. Petrophysical interpretations by using of IP software shows Sarvak reservoir is divided into 3 zones (4، 5، 6). This study reveals that zone 4 contains the best reservoir quality in compare with the others by having (17m) oil column. porosity (more than 8%) and water saturation less than (14%) in this field. There is also decreasing of water saturation in Pay zone 4، but no significant changes has been observed through out zones 5&6. In zone 4، shale volume increases in zones 5&6 (Vsh more than 25%). Crossplot K-Th and K-Pe reveals that Chlorite_Montmorilonite are the dominant clay minerals in this reservoir.