This paper considers the huge changes in the oil industry's understanding of multiphase flow over more than 4 decades, and the application of that understanding into the engineering discipline of flow assurance that has developed in the same timeframe.
Initial test facilities were simple horizontal pipes carrying air and water at near atmospheric pressure and temperature. Then came larger, pressurised facilities using model hydrocarbon fluids. Now the oil industry has complex subsea production systems in deep water with reservoir fluids flowing over long distances and experiencing large changes in pressure and temperature. Fundamental understanding of the behaviour of the fluids and flow is key to the flow assurance discipline, and to the efficient design and operation of such production systems.
Techniques for visualising and modelling the flow, required to manage the various characteristics of the fluids and flow behaviour, are discussed. Significant challenges remain for flow assurance before it can predict all aspects of fluid and flow behaviour sufficiently accurately for risk management in all applications. Opportunities exist in oil and gas field development projects, and in subsequent operations, to instrument and monitor flow and fluid behaviour both for the benefit of the operation and for validation and improvement of models used in design.