Describing physical properties of reservoir rocks is of great interest. Lab testing can be expensive, and may not have the desired spatial sampling for long cores. Here, we describe a hand sample of a carbonate rock comprised of calcite and dolomite. We use digital rock physics to numerically estimate how density, porosity, and electrical conductivity change along and across bedding (vertically and laterally). This spatial sampling is higher than possible with standard laboratory methods such as core plug or whole core analysis. Our digital models were acquired through X-ray micro computed tomography (CT). Calcite and dolomite have different X-ray attenuation properties, and have historically been difficult to interpret when captured in the same dataset. We have overcome this issue by strategically picking our scan’s source voltage and understanding dolomite’s unique attenuation "discrepancy" at a given condition. A density model was created using phantoms of known density scanned alongside the sample for calibration. A porosity model was made using the inverse relationship between porosity and density. An electrical conductivity model was created with an effective medium theory. The anisotropic conductivity results suggest that there is directionally favoured conductivity and permeability across a visible fracture. Density and porosity results are similar to plug results.
Presentation Date: Monday, September 16, 2019
Session Start Time: 1:50 PM
Presentation Start Time: 4:45 PM
Presentation Type: Oral