JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING, cilt.47, ss.123-135, 2005 (SCI-Expanded)
The shallow marine lithofacies of Kuzgun formation represented by porous reservoir facies are predominantly represented by the sandstones of Middle-Upper Miocene age. On the basis of texture and mineralogy, the sandstone formation may be classified into three lithological units as a lithofacies-1, -2, -3. The impervious lithofacies-1 (non-reservoir) sandstone formation is represented by alternating layers of mudstone/sandstone exhibiting bioturbation characteristics. The lithofacies-2 and lithofacies-3 units constitute the main reservoir facies in the sandstones of Kuzgun formation. Their microporosity is associated mostly with clay minerals. Approximately one-half of the outcrop sand samples has excellent reservoir potential based upon petrographic, scanning electron microscopy-energy dispersive spectrometry, porosity, permeability and capillary pressure analysis. Sections of the reservoir containing more poorly sorted, and with smaller grain size and grain coating and pore filling authigenic clays, have experienced less exposure to pore-fluid flow and thus less effective porosity and permeability development has occurred. These differences have led to variations in reservoir characteristics such as porosity, permeability, and pore throat.