Petrophysical Investigation of the Khurmala Formation in Taq Taq Oil Field, Zagros Folded Belt

Abstract

The Tertiary rocks of Khurmala Formation in the TaqTaq oil field have been studied using wireline log analysis, drilling cutting descriptions with integration of mud logging report, and test results for understanding reservoir potentiality and fluid distribution. The formation comprised dolostone and dolomitic limestone with an intercalation of clay layers between the recognized beds. The formation has variable thickness throughout the field, 99.8 m from the northeastern limb and 109 m in the southeastern plunge. The calculated shale volume in the studied interval shows a high rate of the clay contents which in some points the gamma ray has 100% of shale. (Kh-1, Kh-2, Kh-3, Kh-4, and Kh-5). The first (Kh-1), third (Kh-3), and fifth (Kh-5) porosity units have the average porosity ≥0.10 (10%) that can be considered as good reservoir unit in terms of porosity, whereas the shale contents reduced the reservoir quality of these units. However, well hydrocarbon entrapment through interconnected fractures and fault in the other Tertiary reservoir was recorded in Taq Taq field , but the weak connectivity of the pores in the Khurmala Formation caused this rock interval remains as water bearing zone. The corrected log-derived bulk porosity subdivided the Khurmala Formation into 5 porosity units from the top to the bottom including

Liquid and Gas Corrected Permeability Correlation for Heterogeneous Carbonate Reservoir Rocks

“…This diversity in permeability distribution derived from the fact that the reservoir permeability does not depend on porosity alone in carbonate rocks. The magnitudes of permeability are sufficiently influenced by the rock microstructure and pore system [32,33,34,35]. Furthermore, this heterogeneity in rock components and reservoir properties reduce the appropriateness of the established equation for estimation liquid permeability in different types of reservoir rocks.…”