Application of Medical and Dental CT-Scan for Characterizing Carbonate, Evaporates, Marl and Sandstone

Abstract

Summary Application of imaging technology assists careful analysis of petrophysical properties without the need to destroy sample. In this paper, methods of medical and dental CT-scans are applied for porosity determination in 20 core samples from Persian Gulf coastal zone, Zagros basin and compared with routine porosity measurement. The core samples were salt, sandstone, marl, calcite-carbonate and dolomite-carbonate collected from Gachsaran, Aghajari, Dalan, Asmari and Kangan formations in Zagros basin. Digital rock images were obtained using dental CT scan with a resolution of 200 pixel per μm and medical CT scan with a resolution of 100 pixel per μm. For analysis of dental and medical CT scans, OnDemand3D and PACSPLUS CD Viewer softwares were used respectively. In addition to dental and medical methods, average porosity was determined using nitrogen porosimeter and compared with imaging measurements. Results showed that average porosity obtained from laboratory method is in good agreement with two other methods. The results of this study illustrate that the use of dental CT-scan is superior to measure the petrophysical properties of porous rocks. CT-scan method responded well for sandstone and calcite-carbonate rocks, but not good enough to evaluate dolomite-carbonate, marl and salt rocks.