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Global carbon intensity of crude oil production

Mohammad S. Masnadi, Hassan M. El-Houjeiri, Dominik Schunack, Yunpo Li, Jacob G. Englander, Alhassan Badahdah, Jean-Christophe Monfort, James E. Anderson, Timothy J. Wallington, Joule A. Bergerson, Deborah Gordon, Jonathan Koomey, Steven Przesmitzki, Inês L. Azevedo, Xiaotao T. Bi, James E. Duffy, Garvin A. Heath, Gregory A. Keoleian, Christophe McGlade, D. Nathan Meehan, Sonia Yeh, Fengqi You, Michael Wang, Adam R. Brandt (2018)

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The article presents an approach to modelling the well-to-refinery carbon intensity of major active oil fields globally and to identify major drivers of these emissions. It looks both at country-level and field-level upstream carbon intensity (CI). It estimates the total petroleum well-to-refinery GHG emissions in 2015 as ~1.7 Gt CO2eq., ~5% of total 2015 global fuel combustion GHG emissions, which is much higher than comparable industry estimates. It finds that gas flaring practices have a considerable influence on carbon intensity, accounting for approximately 22% of the global volume-weighted-average upstream CI. Gas flaring is a major contributor to the upstream emissions of conventional producers with above average CI, including Algeria, Iraq, Nigeria, Iran, and the United States. Major producers of unconventional heavy oils, notably Venezuela and Canada, which need large amounts of energy for extraction and upgrading, have high country-level CI. Saudi Arabia has one of the lowest CI, due to limited flaring, a small number of large fields, and relative ease of extraction. 


The article suggests data-driven carbon intensity estimates can encourage improved practices, including prioritising sourcing crude oil from fields with low CI, can suggest methods to manage crude oil CI and, and can equip governments and investors to avoid locking in high-emissions crude oil resources. Specific policies touched on include: focusing upstream mitigation measures on fields in the upper end of the CI curve; ensuring regulations reward improved production practices with clear per-barrel incentives for the lowest CI producers; and mitigating oil-sector emissions through wise resource choices and improved gas management practices (including stringent flaring and venting management).  


This article can be used to support (or dispute) claims about the upstream emissions intensity of fossil fuel projects proposed in fields analysed in the article. Where project proponents rely on lower estimates than given in this article, the article can be used as counter evidence. Proponents of projects may use the emissions intensity data from this article to show the proposed project will be less emissions-intensive than alternatives. The article can be used to scrutinise such claims.    


This article can be also used to demonstrate the importance of regulating processes within the extractive activity to minimise emissions. Where a project will not be rejected, the article can be used to advocate for the imposition of stringent conditions on the permit to ensure the lowest carbon intensity can be achieved.  

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