Improving the fidelity of multiphase flow models is critical for the ability of the energy industry to reduce the costs of development and operation. The principal challenge for multiphase flow models, in terms of uncertainty, is the difference in scale and some of the fluid properties between field and laboratory conditions. Therefore, the models may become unreliable when they are applied to conditions that are very different from those in the laboratory. For multiphase flow, studies on dimensional analysis and scaling are quite scarce due to the complexity of the systems.
IFE has recently developed and demonstrated scale-up rules for the most basic multiphase pipe flows. Earlier, the scaling rules were tested by designing experiments in IFE's medium-scale multiphase flow loop to compare with data from SINTEF's largescale facility. The focus of this paper is on the selection of appropriate data from our existing data base and on the design of new, scaled laboratory experiments, which will be well suited to demonstrate (or test) the scaling rules. The data include fluid properties, pipe configurations and flow rates. Besides the observed flow pattern, the liquid holdup and pressure gradient are the two main parameters for comparison.
IFE's CO2 flow loop, with an inner diameter (ID) of 44 mm, operates for two-phase flows over a large range of pressures and temperatures to cover the equilibrium line. A set of experiments was run to simulate similar conditions, according to the scaling rules, to verify the scale-up principles. The flows are fully developed, steady state, two-phase vapour-liquid, in a horizontal or near-horizontal pipe. The flow regimes include stratified, annular, and slug flows. The experimental results showed that flow regimes, liquid holdups, and pressure gradients in the CO2 flow loop are in excellent agreement with the experimental data from the large-scale facilities. The results also confirm that the gas-to-liquid density ratio plays an important role, as showed in . The experiments have provided valuable data sets for the verification of the scaling laws.