Jianlin Peng (Master of Science in Petroleum Engineering)
Experiments and Modeling of ESP Performance with Viscous Oils and Oil-Water Emulsions
Conclusions and Recommendations
A General Electric (GE) TE-2700 14-stage radial type electrical submersible pump (ESP)was tested with a 3-inch closed flow loop under different viscous oil flow conditions. A pipe-in-pipe heat exchanger was used to cool down the temperature. The ISO-VG320 oil was used as a working fluid for single-phase oil tests. Tap water was added to create oil-water emulsions. At water fraction: 0 and 5%, and different rotational speeds (1800 rpm, 2400 rpm, 3000 rpm, and 3500 rpm), flowrates, pump head, and temperature were recorded, and the ESP performance was characterized. Mass flowrate and density were monitored using the mass flowmeter. Fluid samples were collected during the tests, and viscosity-temperature relationships for both single-phase oil, and oil-water emulsions were measured using a rotational rheometer. The ESP performance declined with the increase of fluid viscosity.
A mechanistic model was developed based on the Euler theory to predict ESP hydraulic performance. The head losses, including friction loss, turn loss, leakage loss, and recirculation loss, were subtracted. The friction factor correlation in the ESP performance model was modified.
Compared with the original mechanistic model, predictions by the improved model show a better agreement with the experimental data at low flow rates. Emulsion rheology was modeled by considering the effects of droplet size, friction, shear, and stage number with corresponding dimensionless numbers. Results agree well with the experimental data, but additional data are required to verify the model generality in the future study.