Digital rock physics and application of high-resolution micro-CT techniques for geomaterials

Understanding the behaviour of rocks at microstructural levels is important for interpreting their macroscopic behaviour and the long-term successful implementation of their engineering applications like underground coal gasification, geothermal energy extractions, enhanced oil recovery, geological carbon sequestrations etc. Digital Rock Physics (DRP) is an alternative way for optimization and measurement of various image-based rock properties like porosity, permeability, electrical conductivity and elastic modulus and has been useful due to its high-resolution insight into the complex rock structure. DRP using micro-CT techniques includes image acquisition, image processing followed by the numerical experiments by means of the field equations and their solutions. The foremost microscopic attributes of rocks are pore volume, pore radius; pore coordination number, throat radius and throat channel length and these can be quantified precisely with the application of micro-CT technique. Additionally, pore-network model and flow behaviour simulation can also be achieved using this technique. In the current study, the advancement and usefulness of micro-CT techniques for geomaterials like rocks is discussed and summarised. Further, the technique is applied to an Indian sandstone to evaluate the above-mentioned rock properties.