A PRACTICAL APPROACH FOR MEASURING ENERGY AND CARBON PERFORMANCE OF TURBOMACHINERY IN OFFSHORE APPLICATIONS

Abstract

The purpose of this work is to present the first results of a practical approach developed for measuring the performance on energy and carbon of turbomachinery installed at offshore oil production plants, based on the methodology described in ISO 50006 (2014) and on the best practices from the oil and gas industry. Energy and carbon indicators are proposed at facility, system, and equipment levels to monitor the overall performance of the platform and to detect performance gaps related to a particular system or equipment of concern. Considerations are made on the open-source monitoring tool used for the assessment. Power demand profile and available data of the most energy intensive equipment from an existing Floating Production, Storage and Offloading (FPSO) are provided as a background for the proposed screening criteria for equipment and systems to be monitored. A case study based on an existing Pre-Salt FPSO is presented to illustrate the results obtained with the proposed framework. Primary processing scheme and a turbomachinery arrangement highlight the characteristics of a typical FPSO operating in Brazilian Pre-Salt fields. Some discussions on the influence of operating modes on the FPSO energy and carbon performance show the challenges encountered in establishing an adequate baseline for the proposed indicators at the facility level, especially due to the gas treatment system for CO2 removal. A statistical approach applied to some compressor efficiency datasets has led to practical conclusions on how efficient gas compression is at the equipment level, as time trend plots directly generated from the compressor efficiency datasets show high fluctuations due to the sensitivity of the calculated variable to the uncertainty of the instrument readings. Furthermore, the effect of optimizing the number of gas turbine generator sets in operation on the overall carbon emitted by the power generation system is presented to illustrate one possible action for raising the FPSO energy and carbon performance. The proposed approach has proven useful for quickly detecting deviations and for tracking the effects of improvement actions on the FPSO energy and carbon performance. Indeed, by applying performance indicators at different levels of the facility, oil and gas companies should be able to identify bad actors in energy and carbon related to a particular equipment or system and to predict and compare the performance of new FPSO projects in relation to existing oil production plants. The results presented in this work show that the proposed approach is promising in driving turbomachinery energy performance and promoting decarbonization.