A new model to predict the head degradation of centrifugal pumps handling highly viscous flows

Petroleum companies use Electric Submersible Pumps (ESPs) as an artificial lift technique to improve oil production. When centrifugal pumps operate with oil or other viscous liquids, their performance is generally degraded with respect to regular design operation with water. There are several procedures in handbooks or in literature to correct centrifugal pump performance operating with oil. Nonetheless, most of those procedures are pump specific or require geometric parameters that are hard to obtain. Moreover, regular affinity laws are not fully applicable to performance estimation when a pump operates with highly viscous liquids. All those issues are considered in this investigation, where a new model is proposed to estimate head and flow rate degradation of a centrifugal pump operating at a broad range of Reynolds numbers, which include high liquid viscosities and low rotating speeds. The model is based on data from two mixed flow type ESPs and one radial type pump for rotating speeds up to 3500 rpm and kinematic viscosity up to 822·10−6 m2/s. An advantage of the present model is that it does not depend on any geometric parameter, depending only on the water baseline curve and ordinary design quantities that are usually available in pump datasheets. Predictions from this model and other standards from the literature (HI and KSB methods) are compared to the data used. The maximum deviations from the proposed model, HI and KSB were 53.3%, 176.5%, and 136.2%, respectively. Then, the proposed method proved to be superior compared to these well-known procedures. •A new algebraic model to predict head and flow rate viscous degradation in pumps is proposed.•The model can be applied for selected operating conditions or an entire curve.•Results agree well with published data for a wide range of Reynolds numbers.•The method performs generally better than well-known standards from literature.•Constructing a complete chart with the model for a given pump is straightforward.