Development of core analysis procedures using x-ray computerized tomography. Quarterly report, September 1, 1988--November 30, 1988

摘要

In a letter from John C. Lorenz of Sandia National Laboratories dated November 8, 1988, analyses of interest included. With the core received, measurements are not possible. Core must be loaded into a passive vessel to flow various fluids for permeability measurements. Because the core was slabbed and plugged, this was not possible. Microfractures or porosity distribution can also be seen by flowing two fluids with contrasting attenuation coefficients and using a subtractive imaging technique. This again could not be done because core could not be inserted into a flow vessel. Similarly, fracture interconnections could not be measured. Each cross-sectional computerized tomography image is made up of a 256 (times) 256 array of data. This data array is composed of CT numbers which are collected from the scanner. These CT numbers are defined as normalized attenuation coefficients for the material being scanned. At the energy level used for this data, the CT numbers are approximately proportional to the density of the sample material. Subsequently, colors are, assigned arbitrarily to the CT numbers to highlight contrasts in density in the core. Red is assigned to higher-density regions and blue to lower density regions. Variations from red to blue are shown in the color bars to the left of the images. (ERA citation 17:027358)