Routine core analysis
The set of measurements normally carried out on core plugs or whole core. These generally include porosity, grain density, horizontal permeability, fluid saturation and a lithologic description. Routine core analyses often include a core gamma log and measurements of vertical permeability. Measurements are made at room temperature and at either atmospheric confining pressure, formation confining pressure, or both. Routine core analysis is distinct from special core analysis (SCAL).
Special core analysis (SCAL)
Any measurements made on core plugs or whole core that are not part of routine core analysis. Most special core analysis concerns reservoir properties, electrical properties and petrographic studies. The reservoir properties measured include relative permeability, wettability and capillary pressure. Electrical properties include formation factor, resistivity index and cation-exchange capacity. Petrographic and mineralogical studies include scanning electron microscopy, thin-section analysis, X-ray diffraction, X-ray fluorescence, elemental chemical analysis and Fourier transform infrared spectroscopy.
Other special core analyses are concerned with grain size determination (by sieve analysis or laser diffraction); characteristics of the fluids, such as oil viscosity and water salinity; and mechanical properties such as pore volume compressibility and seismic velocities.
