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Despite the common presence of water in oil production, just recently, the scientific community has devoted efforts to studying the influence of emulsion phenomena effects related to oil production using pumps. In the context of this study of phase inversion phenomena, the influence of viscosities and rotational speeds in electrical submersible pumps (ESPs) are evaluated as part of this effort. This study is aimed at investigating the influence of viscosity in phase inversion phenomena. An eight-stage ESP was tested with three different rotational speeds and two different oil viscosities for the best efficiency point (BEP) flow rates. Initially, the total flow rate was obtained in relation to BEP using ESP performance curves for pure oil at 52 cP and 298 cP and rotational speeds of 800 rpm, 1200 rpm, and 2400 rpm. The total flow rate was kept constant and the water cut was increased from 0 to 100%. The inversion phase phenomenon was detected by performance improvement when the water cut increased. The factors analyzed were the head and efficiency of the ESP as a function of the water cut. The phase inversion experimental data obtained in this study were compared with literature models for horizontal pipes. The results of this comparison presented satisfactory agreement. The phase inversion phenomena occur in all eight stages at the same time. Hysteresis was observed in ESPs for oil viscosity of 52 cP and rotating speed of 800 rpm and 1200 rpm.

Emulsions are common during oil production, and this is the case of the Peregrino field, e.g. . In several fields, oil and reservoir fluids can be produced through Electrical Submersible Pumps (ESP) and the formation of emulsion affects the ESP system, its run life, and the production itself. The viscosity increase due to emulsion formation severely hampers the ESP performance, requiring an increase in energy consumption on the platform to keep the same production rate. This work presents an initial validation of the model proposed by Bulgarelli (2021) to predict the water-in-oil emulsion effective viscosity within the ESP and its impact on lift capacity. The model can aid the design of the ESP system and can be used as a flow rate estimation tool during ESP production. The initial validation was performed using data from water-in-oil emulsion production of the two wells (A and B) in the Peregrino field, which use two different ESP models. The validation was divided into two parts: the first corresponds to Technology Readiness Level (TRL) 3 and the second, TRL 4, according to ISO 20815:2018. Firstly, well tests data were used to calibrate and test the model for initial validation of the TRL 3. Operation data of these two wells were then used for the initial validation of the TRL 4 in the second part. In the first step, measured and predicted ESP head were compared. Mean Absolute Percentage Errors (MAPE) of 3.6% and 0.8% were obtained for Wells A and B, respectively. In the second part, both the measured and predicted ESP dimensionless head and the measured and predicted differential pressure were compared. From these comparisons, promising results were observed for both wells' operations. However, more oil data field is necessary to complete the TRL 3 and TRL 4 validation.