In oil-water two-phase dispersed flow, phase inversion may occur when the continuous phase becomes dispersed. This phenomenon, which controls the nature of the phase in contact with the pipe, has a great importance on the corrosion and on the pressure drop, which dramatically affects the delivery ability and operational modality. It is therefore imperative for the phase inversion research to be taken into consideration. However, most of the knowledge on phase inversion is for light mineral oil with low viscosity, few research focuses on high viscosity oil-water phase inversion. Arirachakaran et al. (1989, “An Analysis of Oil/Water Flow Phenomena in Horizontal Pipes,” SPE Professional Product Operating Symposium, Oklahoma, SPE Paper No. 18836) found that critical water fraction when inversion occurred was dramatically reduced with the increment of oil viscosity, and the existing phase inversion models are invalidated. In this paper, an experimental study has been made of high viscosity mineral oil-water flow through a horizontal pipe loop. Results indicate that phase inversion for oil phase with high viscosity occurs much earlier than low viscosity oil, and phase inversion tends to be delayed, with the increment in experimental temperature. The influence of mixture velocities on the inversion process could be neglected in the range of mixture velocities that we studied. As well, inversion point obtain by our experiment are best predicted by the correlation of Arirachakaran et al. (1989, “An Analysis of Oil/Water Flow Phenomena in Horizontal Pipes,” SPE Professional Product Operating Symposium, Oklahoma, SPE Paper No. 18836). Models of Decarre and Fabre (1997, “Phase Inversion Prediction Study,” Rev. Inst. Fr. Pet., 52, pp. 415–424) and Braunerand Ullmann (2002, “Modeling of Phase Inversion Phenomenon in Two-Phase Pipe Flows,” Int. J. Multiph. Flow, 28, pp. 1177–1204), based on minimization of system total energy, seem to be invalidated for high viscosity oil.
Experimental investigation of high-viscosity oil–water flow in vertical pipes: flow patterns and pressure gradient
