In this paper a mathematical model is developed to predict temperature profiles for two-phase oil-water stratified flows. Estimating two-phase fluid temperatures in pipelines is demanding in offshore deepwater producing environment where dramatic heat transfer may occur due to greater temperature difference between fluids and ambient, for example, subsea ambient temperature can be as low as 4°C and the fluid temperature can be in the range of 70 to 150°C. Accurate temperature as well as pressure predictions is imperative for facility design and flow assurance issues such as paraffin deposition, hydrate formation, fluid viscosity increase, etc.
Based on energy balance of a control volume, analytical solutions are derived for prediction of temperature profiles in pipe flows for two-phase oil/water stratified flow pattern. The model has been verified with single-phase heat transfer model which is available in most heat transfer textbooks. Two typical cases are simulated for extreme operating conditions with water cut of 0% and 100%, respectively. The heat transfer model can be used to predict the fluid bulk mean and wall temperatures along the pipe.
This analytical model is also validated against experimental data. The test was conducted on a multi-phase facility with accurate flow control devices and effective thermal treating units. The water cut was set at 50% for the test. The simulation results and experimental data agree within the experimental uncertainty. The closure relationships can be conveniently applied to two-phase oil/water paraffin deposition model which is dependent on heat transfer process. The model is also used to predict the temperature profiles for two-phase oil and water flows with different water cuts.