(68d) Fundamentals of Emulsion Behavior: Toward an Understanding of Critical Flow Assurance Challenges

While the behavior of oil into water emulsions and dispersions is relatively well understood, the behavior of water into oil emulsions and dispersions is less well grounded in fundamentals, particularly for multiphase transport in oil pipelines, even under well dispersed conditions. Accurate knowledge of water drop size distribution (DSD) is required to design separation equipment and to assess the potential for gas hydrate formation in deep sea pipelines. In turbulent flow, the pumping and power requirements are determine by geometry and the macroscopic properties of the multiphase mixture. However the drop size, particularly for stabilized emulsion and dispersions, is controlled by microscale flow features that exist on the drop scale and depend on local energy dissipation rate and the kinematic viscosity of the carrier phase. In water like flows, oil drops generally find themselves in a well characterized turbulent flow but in oil flows, water drops often find themselves in a laminar like flow field, since their size can be less than that of the smallest turbulent eddies. In this talk, we will introduce the basic features of turbulence on small scales and discuss currently accepted methods for predicting drop size for oil into water dispersions. We will then consider the state of knowledge for predicting drop size for water into oil dispersions. Critical gaps in data and theory will be assessed and the need for further studies will be discussed. Considerable emphasis will be placed on extrapolating data acquired in stirred vessels, static mixers and other contactors to conditions that exist within the flow assurance environment.