Ali Ranjbar

Comprehensive study of a reservoir is possible through a correct and accurate analysis of reservoir petrophysical properties and their distribution pattern in geological formations. Application of imaging technology assists a careful analysis of petrophysical properties without destroying samples. In this study, medical and dental CTscan techniques are applied for porosity determination of 20 core samples collected from Persian Gulf coastal zone and Zagros basin in order to compare with routine porosity measurement technique. The studied core samples included salt, sandstone, marl, calcite-carbonate and dolomite-carbonate collected from Gachsaran, Aghajari, Dalan, Asmari and Kangan Formations in Zagros basin. To obtain average porosity for each sample digital rock images were obtained using dental and medical CT-scan techniques and analyzed through image processing. In addition, average porosity was determined using nitrogen porosimetry and compared with imaging measurements. Results showed a considerable agreement between CT-scan techniques and average routine porosity method. However, the high-resolution dental CT-scan technique is superior to medical CT-scan technique for porosity determination through image analysis. Moreover, CT-scan responded well for sandstone and calcite-carbonate rocks, but not sufficient to evaluate dolomite-carbonate, marl and salt rocks.