Experiments have been conducted to study the ability of heavy oil-water mixtures to transport sand. The oil-water mixtures were not emulsions. Using crude oils and a viscous lubricating oil at various temperatures, the viscosity of the oil phase was varied between 2.1 and 26.4 Pa·s. Sands with median diameters of 0.08, 0.18, 0.25 and 0.29 mm were used at in-situ sand concentrations of 10% and 20% by volume in recirculated flow in laboratory pipelines of internal diameter 0.053 and 0.105 m. The flow regime was found to be strongly dependent on water fraction and the low pressure gradients associated with continuous water assisted (CWA) flow was achieved only when the water fraction was greater than about 40% by volume. The ability of a flow to transport sand was found to be strongly dependent on the axial pressure gradient, with sand particle diameter also playing a significant role. Further investigation would be required to construct a credible mechanistic model.
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