Rayleigh-Taylor Instability of Bingham Fluids

The effect of a fluid’s yield stress is investigated on the Rayleigh-Taylor instability as encountered during cement plugging of oilwells. The two fluids were assumed to be immiscible having different densities and yield stresses both obeying the Papanastasiou- Bingham model. The unsteady equations of motion were solved using OpenFoam software. Based on the results obtained in the present work, it is concluded that the yield stress of either fluid has a stabilizing effect on the interface. The stabilizing effect of the yield stress is predicted to depend on the amplitude and wavelength of the initial perturbation.