Million node fracture: size matters?

Abstract Transmissivity of self-affine fractures was computed numerically as a function the grid size. One-million-node (1024 × 1024 nodes) with fractal dimensions 2.2–2.6 were cut into successively smaller (“generations”), and transmissivities computed. The number in each generation increased by factor 4. Considerable scatter transmissivity observed for sizes. Average decreased size, without approaching any asymptotic value, which indicates no representative elementary volume (REV). This happened despite average mean aperture being same generation. results indicate that it is not possible to estimate large fracture cutting fractures, running flow simulations on those averaging results. decrease size found be due an increase tortuosity.