Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
Lifetime Exergy Analysis of Electricity and Hot Water Production Systems in Offshore Projects with Multiple Platforms
Submission Author:
Ronaldo Lucas Alkmin Freire , SP
Co-Authors:
Ronaldo Lucas Alkmin Freire, Silvio de Oliveira Junior
Presenter: Ronaldo Lucas Alkmin Freire
doi://10.26678/ABCM.ENCIT2018.CIT18-0319
Abstract
Systems for production of electricity and pressurized hot water in offshore oil and gas production platforms are typically designed with open cycle gas turbines with waste heat recovery units due to high power demands combined with area and weight constraints. This paper aims to present the results of an investigation on the exergy efficiency of two alternative designs to that adopted in Pre-Salt platforms. The first alternative considers the replacement of the GE LM2500+ gas turbines by GE LM2500PE combined-cycle units, thus maintaining the energy self-sufficiency of each platform. The second considers a central power plant with GE LM6000PG combined-cycle units to supply the electrical demand of four platforms and gas heaters for hot water in each production platform. This work also considers a delay of production between platforms of 1 to 4 years, changing the lifetime curves of electric and thermal demands of the multi-platform production system. In general, the Alternative 1 shows the highest exergy efficiency throughout the oil field life. However, this technical solution is quite challenging for future projects due to a severe Rankine cycle allocation restriction onboard. The centralization of the electricity production in high efficiency combined-cycle power plants did not show advantage over the traditional platform design with open-cycle gas turbines with exhaust gases energy recovery for hot water production. The production starting time changing from 1 to 4 years did not modify the conclusion of this work.
Keywords
offshore platform, power and heat systems, Exergy Analysis, project life
