An Integrated Solution Enabling Allocation of Heavy Oil in the Peregrino Field

Abstract

An Integrated Solution Enabling Allocation of Heavy Oil in the Peregrino FieldUnconventional oil plays a growing role in the petroleum industry, especially in operational regions such as Latin America, China and Canada. The complexity of producing from a heavy oil reservoir is a challenge not limited only by 'economics' but also by the available technology. There are various methods of producing from heavy oil reservoirs ranging from open-pit mining to steam assisted production. 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 the allocation performance of the downhole flowmeters used in the Peregrino field, Brazil. Peregrino is located offshore of Brazil and the ESPs and flowmeters will be used for the multiple wells in the field. There are huge variations in the well's behavior such as production rates as well as bottomhole pressure.Before field deployment, a test was commissioned to benchmark the performance of the ESPs and flowmeter when working in tandem. Different sizes of flowmeters were tested over the flow range of 500stb/d and 30,000stb/d and up to 360cP in oil viscosity. New correction methods were employed to improve the measurement accuracies such as an iterative calculation of the flowmeter discharge coefficient based on the measured fluid properties. The results from this test will help to validate the performance of the ESP while the flowmeter allocation accuracies can be verified to meet the Brazilian authority (Agencia Nacional de Petroleo -ANP) specification. The lessons learned will be applied towards future field allocation applications using downhole flowmeters in the Peregrino field.