Using information acquired from microscanner logs in horizontal boreholes, fracture apertures are shown to be characterized by multifractal scaling. A representative f-&agr; spectrum can be modeled using a multiplicative cascade based on a two-scale Cantor set. The resulting cascade can be used to simulate fracture aperture distributions at any scale. When compared to well data, the simulations show good agreement with aperture sizes and reproduce the clustering commonly recognized in fracture networks. ¿ American Geophysical Union 1994