Fluid flow through natural fractures depends upon the scaling behaviour of their fractually rough surfaces. We have developed techniques for imaging fluid flow in the natural rock fractures themselves, in high fidelity physical models, and by using high-resolution numerical simulations. These advances will be used to examine the scaling behaviour of miscible/non miscible fluid flow in fractures, paying particular attention to (i) channelling, fingering, dispersion and flow stability, (ii) surface wettability, (iii) normal and shear deformation, and (iv) the nature and development of fractural fracture matching, experimental (optical, NMR and PET) imaging will be carries out concurrently with numerical modelling on a suite of tuned synthetic fractures. The results will be applied to multi-fracture systems of interest to the oil industry and UK NIREX Ltd.