The main objective of the multiphase transport project is to perform experiments and modelling to reduce the gaps in the understanding of multiphase transport processes of viscous oils, and to better understand the underlying micro/meso scale phenomena that influence the macro scale flow assurance problems. This covers the areas such as the dispersion of gas bubbles and water drops into viscous oil, the influence of viscosity and possibly surfactants on flow patterns and the formation and stability of emulsions and other dispersed flows.
There is a gap between measurements that can be done with existing instrumentation and the wish for more detailed measurements. Some of the main challenges are the opaqueness of the oil phase and thin liquid films on the wall. Ultrasound Velocity Profiler (UVP) is a relatively new technique for measurement of mean velocity and turbulence characteristics of a dispersed phase. Wire mesh systems (WMS) are a newly developed type of tomography system based on conductance and/or capacitance measurements from a fine wire mesh covering the pipe cross section. For drop size measurements the potential of using commercial laser diffraction instruments (Malvern) as well as optical probes and impedance needles will be investigated.The experiments and modelling efforts will result in better understanding of phase distribution, pressure drop and flow regime transitions in gas/liquid flow with viscous oil.
The host institutions IFE and SINTEF have a broad range of instrumentation relevant for characterizing viscous oil pipe flow. The equipment includes a broad beam gamma densitometers, a traversing gamma densitometer. An X-ray tomography system with high time resolution is available for instantaneous measurement of cross sectional fluid distribution in two- and three-phase flows. For detecting whether the pipe wall is oil or water wetted, conductance probes are available. Use of combined particle image velocimetry (PIV) and laser induced fluorescence (LIF) may enable measurement of velocity profiles in the liquid. For measurement of drop sizes we may use optical techniques.
Bubble and droplet size distributionsCommercial codes for simulation of multiphase transportation of oil and gas have only been well validated for gas condensate and light oil/gas systems. This is partly due to a lack of data for high pressure and/or three-phase flow with oil viscosity above 50 cP, and partly due to the formidable challenges of modelling these complex systems. There is therefore a need to acquire data and develop and test new and more accurate models for viscous gas-oil-water systems. To achieve this, we first need to better understand the simpler oil-water and gas-oil systems.
Published August 30, 2010
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