As the environmental impact is critical for industry sustainability, early quantifying Greenhouse Gas (GHG) emissions of offshore units represents a central role and step-change improvement across the O&G value chain. Developing an overarching realistic model to estimate GHG emissions is a challenge due to the different methodologies available, the complexity of offshore installations, and the degree of uncertainty in the estimation of emission factors.
The present work focuses on the earlier stages of new development, notably in Front End Loading-1 (FEL-1) and FEL-2, i.e., opportunity identification and conceptual engineering studies, respectively. The primary objective of this study is to propose an innovative modeling methodology to quantify Greenhouse Gas (GHG) emissions in offshore production facilities. Since E&P companies consider current and future carbon dioxide equivalents (CO2e) emissions as a factor into capital projects economics, this study additionally proposes a semi-empirical model for OPEX calculation considering the impact related to emissions (on a CO2e basis).
Emissions of GHG in the O&G industry typically occur from one of the following general source classes: (i) combustion sources, including both stationary devices and mobile equipment; (ii) process emissions and vented sources; (iii) fugitive sources; and (iv) indirect sources. The projection of carbon emission costs along the asset life cycle is performed to simulate the economic impact of such emission on an OPEX perspective. After estimating the CO2e emissions, the procedure consists of using the "Carbon Emission Cost Projection" to calculate the cost of the CO2 emitted and penalize the OPEX of the evaluated alternative.
The proposed model can be used to estimate Carbon Footprint for each one of the several conceptual engineering alternatives evaluated during the conceptual phase of the project, improving not only the techno-economic analysis but also the decision-making process of Capital Projects in the O&G Industry.