Net energy assessment of petroleum extraction: the Brazilian pre-salt layer as case study

• Grant number: 15/22771-4
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2016
• Effective date (End): May 31, 2017
• Field of knowledge: Engineering - Production Engineering
• Principal researcher: Feni Dalano Roosevelt Agostinho
• Grantee: Arno Pedro Clasen
• Home Institution: Vice-Reitoria de Pós-Graduação e Pesquisa. Universidade Paulista (UNIP). São Paulo , SP, Brazil

Abstract

The societal development during last century was based on non-renewable resources, basically from fossil energy resources. That dependence on petroleum, natural gas and coal appears to be maintained until 2050, which emerges challenges to society on the generated environmental impacts and in the search for new petroleum reservoirs which is becoming scarce. The recent discoveries of petroleum pre-salt layer reserves in the Brazilian coast highlights the potential of Brazil in becoming a recognized worldwide petroleum exporter. On the other hand, several challenges are imposed by operationalizing and extracting petroleum from the pre-salt layer; this includes economic, social and environmental concerns. Focusing on the energetic-environmental issues, the amount of material and energy demanded by petroleum extraction raises doubt its real contribution to society regarding the net energy; the goal is get a positive benefit-cost ratio. The energy return on investment (EROI) is the most used indicator to assess energy efficiency, and it is derived from embodied energy analysis. Notwithstanding, the emergy (spelled with an "m") environmental accounting appears as a promising complementary tool of the EROI through its indicators emergy yield ratio (EYR) and transformity (Tr). This is especially true because energy recognizes the energy hierarchy in the biosphere through its larger scale of analysis. Thus, this work uses the embodied energy analysis and emergy environmental accounting to calculate efficiency indices which would support a most appropriated discussion about the real energetic-environmental benefits obtained by society through exploring the Brazilian pre-salt layer petroleum.