Experimentation and modelling on the viscosity of oil-water mixtures by the effect of gas injection through pipeline

An Experimental investigation of the characteristics of viscosity for oil-water mixtures disturbed by gas injecting with different input ratios flowing in horizontal pipes was conducted using local sampling method. No.46 mechanical oil, tap water and air were used as the test fluids. A special set combined with Brookfield DV-III + viscometer was designed to get oil-water mixtures sample from the pipe and to measure the viscosity of oil-water mixtures real-time. With increasing of air, oil and water flow velocities, the degree of the oil and water mixing is enhanced gradually, up to forming a semi-emulsion through the entire pipe. The phase inversion induced by the flow appears with about 0.34-0.5 input water fraction. A new correlation for phase fraction of oil-water mixtures was proposed on the basis of experimental data. Considering the mixing effect of oil and water, a mathematical model for the prediction of viscosity of oil-water mixtures was presented, in which the gas velocity, liquid velocity, water fraction in the liquid, as well as oil and water's basic properties are considered. Good agreement between the proposed model and the experimental results is obtained.