Microscopic visualization in rocks under confining pressure by means of micro focus X-ray CT

To visualize the microstructure in rocks under confining pressure, micro focus X-ray CT system that can get three dimensional data simultaneously with high resolution of 10 micron is introduced. A new pressure vessel for micro focus X-ray CT that can be pressurized up to high confining pressure of 100MPa is developed. Using this pressure vessel, the aperture change of preexisting fracture in the cored hard shale was observed. Aperture in the preexisting fracture decreased firmly with increasing confining pressure, and apparently increased with pressure decreasing process. The multi planar reconstruction images enable us to distinguish well between individual grains and pore space. Pore space in Berea sandstone could not change under high confining pressure of 24MPa. It was found that the micro focus X-ray CT with the newly designed pressure vessel provides a useful information about individual particles, voids and cracks as a nondestructive visualizing tool.