Cleat-scale characterisation of coal: An overview

This paper reviews recent developments on the cleat-scale characterisation of coal. Novel micro-CT imaging and image calibration methods are described. The application of micro-CT imaging for studying diffusion processes in ultralow permeability media is shown. The extraction of statistical information from micro-CT images to reconstruct cleats are demonstrated. The developments of microfluidic methods for understanding complex displacement mechanisms in coal seams and variation of coal contact angles are described. We explain numerical methods for prediction of petrophysical properties from micro-CT images and discuss limitations when dealing with coal. The paper concludes by addressing the challenges for microscale coal characterisation.