The structures of natural oil-bearing and synthetic rock were investigated using the ultra small-angle neutron scattering (USANS) technique. The scattering data from different thickness of rock were analysed using a Fourier transform method developed to remove the effects of multiple scattering and to simulate the scattering from a thin rock sample. It was found that only the oil-bearing rock could be analysed using this method. The synthetic rock samples could not be well described by this theory and this is interpreted as due to structural variation in the samples induced by the production method. All the rock samples are found to be surface fractals. The synthetic rock is found to have a much lower fractal dimension (Ds = 2.0), indicating a smoother interface than the natural oil-bearing rock (Ds = 2.7).
