Abstract
The paper reports on the integrated modeling approach for the Gulf of Mexico ultra-Deepwater Perdido Electrical Submersible Pump (ESP) meant for performance surveillance and operational predictions n viscous fluid and multiphase flow regimes. The ESP system uses in Perdido field are multistage centrifugal pumps for high flow rate and high boost applications. Multiphase flow and viscous fluids introduce challenges for ESP operations such as performance degradation and system inefficiency which are imperative and to be considered in modeling work for accuracy and proper surveillance.
The effect results from free gas and viscous fluid could be difficult to model and if not considered can result in wrong prediction of pump performance and power estimation over promising forecast and incorrect performance for surveillance and optimization. The objective of modelling work is aimed to correctly predict ESP performance by using proper modeling equations and correction factors that to understand the degradation on head, flow and horsepower, therefore further guide offshore surveillance activities and near and long term forecast predictions.
The ESP system used in Perdido Field is 1025 series tandem P360 mixed flow type pumps with a 725 series 1600 hp motor. The modeling work revealed mathematical relationships among pump performance parameters (pump speed/frequency, brake horsepower, pump head and pump capacity) and free Gas/Viscosity correction factors required to accurately predict pump performance and forecasting.
Using the correct approach for modeling high boost ESPs, an accuracy of 5% or less can be aimed with field operation for precise pump performance troubleshoot, optimization and long term forecast for economic analysis.
The main technical contributions of this work are the detail modelling approach, analysis and data comparison with Field operation for predicting pump and motor performance under two important variables, high viscosity and two-phase flow inside the ESP.
