BR 
EN Water-in-oil emulsions usually present complex rheological behavior that depends on the physicochem-ical properties of both phases, the presence of surfactants, and the flow conditions. Thereby, this paperaims to propose a criterion to characterize the rheological behavior of stable and unstable water-in-oil emulsions within the centrifugal pumps. This criterion is based on the slip ratio between the dispersedand continuous phases. For this, the droplet size distribution was measured at the ESP outlet and the slipratio was estimated based on the centrifugal buoyancy-induced flow. A new model was proposed todetermine the Sauter mean diameter for different systems of the water-in-oil emulsion flows withinthe ESP based on operational conditions, which presents good agreement with the experimental data(12.6% of error). Finally, a new dimensionless number parameter named Slip Relevance number was pro-posed to separate the different emulsion flow behaviors within the ESP and its critical value was obtained.
Mês: setembro 2021
Relative Viscosity Model for Oil/Water Stable Emulsion Flow within Electrical Submersible Pumps
Electrical Submersible Pumps (ESP) have been used in several scenarios, including water/crude oil emulsion production. The estimation of the emulsion effective viscosity within the ESP is still under discussion due to its complex flow behavior. This work proposes, for the first time, a model to predict the relative viscosity of stable emulsion within an ESP considering the continuous phase properties and ESP operational parameters. The viscosity model was compared to the relative viscosity models for emulsion flow in pipelines and the mean absolute percentage error (MAPE) was 14% and 8% for the stable emulsions without and with demulsifier, respectively. For the same emulsion systems, the relative viscosity model was applied to the unidimensional model to predict the ESP performance with the MAPE of 4% and 2% for the stable emulsions without and with demulsifier, respectively. Furthermore, ESP head degradation operating with stable emulsion with and without demulsifier was investigated experimentally.