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An experimental study of two multi-fluid flows of interest to the oilfield cementing industry Malekmohammadi, Sardar

Abstract

In this work two multi-fluid flows are studied. In the first project, displacement flows in an eccentric annulus were studied experimentally. Displacement flows occur in the oil and gas industry during well construction when drilling mud is displaced by a cement slurry. To remove mud effectively, it is important to design the fluid rheology so that a steady displacement front can be achieved when displacing along an eccentric annulus. In our research, we have investigated the effects of viscosity, density and eccentricity of inner pipe on the interface dynamics. An experimental matrix is devised in a manner to capture the boundary between steady and unsteady displacements for specific pairs of fluids, and to compare against previously published models. Reasonable qualitative agreement was achieved however a systematic discrepancy was observed due to the presence of secondary flows and dispersion in the experiments. These effects have not been studied carefully so far and more sophisticated models are needed to predict this type of flow. In the second project, slumping flows of two non-Newtonian fluids in horizontal closed pipes were studied. This type of flow occurs during the abandonment of horizontal oil and gas wells, when sealing the well through the setting of cement plugs. We have studied the effects of changes in density difference and of small deviations from a perfectly horizontal inclination. The effects of these parameters on the slump length versus time were analyzed. Comparison of numerical and experimental results shows broadly similar trends, but with some qualitative differences also observed, possibly due to interfacial effects

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Attribution-NonCommercial-NoDerivatives 4.0 International