Special Core Analysis (SCAL)

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Computer-Assisted Tomography (CAT) Scanning

A computer-assisted tomography, or CAT scan, produces an image of the internal structure of a cross-sectional slice through an object by reconstructing a matrix of x-ray attenuation coefficients (Figure 1). CAT scanning is a non-destructive x-ray technology that is most familiar through its use in medicine, but which has been found to have oil industry applications as well.

Applications relating to core analysis include:

Visualizing the extent of mud filtrate invasion
Detecting fractures (Figure 2)
Characterizing the lithology of cores contained in opaque preservation material and stainless steel pressure vessels
Screening cores prior to flow tests
Correlating scan data to porosity, permeability and lithology
Waterflooding studies

A good technique for observing the actual progressive movement of fluids inside rocks is to use computer tomography (CT) scanning at successive time intervals to record the displacement or flooding process.

CAT scan image of core, core sample, Special Core Analysis, Capillary Pressure, Relative Permeability, Steady-state and Unsteady state, Wettability Determination, Reservoir Condition Corefloods, Improved Oil Recovery (IOR, EOR) Studies, Petrophysical Correlation Measurements, Archie Exponents a m and n, NMR Core Analysis, Core Geomechanics, Core Mechanical Properties, Pore Volume Compressibility, Formation Damage Remediation, Rock Fluid Sensitivity, Mobile Fines (Fines Particle Migration), Fluid Compatibility, Mud Completion Fluid Damage, Perforation Optimization, Relative Permeability Effects, Asphaltene Precipitation, Computed Tomography CT Scan Evaluation, Petroleum Core Analysis — **Figure 1**: CAT scan image of core

CAT scan of fractures, core sample, Special Core Analysis, Capillary Pressure, Relative Permeability, Steady-state and Unsteady state, Wettability Determination, Reservoir Condition Corefloods, Improved Oil Recovery (IOR, EOR) Studies, Petrophysical Correlation Measurements, Archie Exponents a m and n, NMR Core Analysis, Core Geomechanics, Core Mechanical Properties, Pore Volume Compressibility, Formation Damage Remediation, Rock Fluid Sensitivity, Mobile Fines (Fines Particle Migration), Fluid Compatibility, Mud Completion Fluid Damage, Perforation Optimization, Relative Permeability Effects, Asphaltene Precipitation, Computed Tomography CT Scan Evaluation, Petroleum Core Analysis — **Figure 2**: CAT scan of fractures

Lopez et al. (2012) documented an integrated multiscale imaging and modeling method for determining petrophysical and multiphase flow properties of reservoir rocks at the core pore, sub-plug, plug and whole core scale. The method is based on the integration of multi-scale X-ray computed micro-tomography (MCT) imaging and numerical 3D rock modeling to characterize heterogeneity, pore classes and porosity types at different scales.