Peregrino: An Integrated Solution for Heavy Oil Production and Allocation

Abstract

An Integrated Solution Enabling Allocation of Heavy Oil in the Peregrino Field The complexity of producing from a heavy oil reservoir is a challenge limited by both economics and available technology. Various methods exist for producing from heavy oil reservoirs, but in areas such as Latin America, cold production is used where electrical submersible pumps (ESPs) are employed to artificially lift the oil from the reservoir. This paper highlights an integrated approach of using ESPs and downhole flowmeters in heavy oil production. It will focus on the validation and analysis of production performance from ESPs and the allocation performance of the downhole flowmeters used in multiple wells in Peregrino field, offshore Brazil to address huge variations in the wells’ behavior such as production rates and bottomhole pressure. A test was commissioned to benchmark ESP and flowmeter functions when working in tandem. Three sizes of ESPs and flowmeters were tested over the flow range of 500stb/d and 22,000stb/d and up to 360cP in oil viscosity. The ESPs were operated from 2300 to 3600 rpm in the different viscosity fluids and used water data as a baseline to calculate the performance correction factors for each operating condition. The performance correction factor is incorporated into the development of software to predict the performance of each pump at a specific operating condition. Eventually, the data will be used to develop the ESPs’ monitoring tool. In the downhole flowmeter test, new correction methods were employed to improve the measurement accuracies such as an iterative calculation of the discharge coefficient based on the measured fluid properties. Test results will help validate ESP performance and verify flowmeter allocation accuracies to meet ANP specifications. The lessons learned will be applied toward future field allocation application using downhole flowmeters in the Peregrino field.