title: Life cycle greenhouse gas emissions and freshwater consumption associated with Bakken tight oil.
abstract: In recent years, hydraulic fracturing and horizontal drilling have been applied to extract crude oil from tight reservoirs, including the Bakken formation. There is growing interest in understanding the greenhouse gas (GHG) emissions associated with the development of tight oil. We conducted a life cycle assessment of Bakken crude using data from operations throughout the supply chain, including drilling and completion, refining, and use of refined products. If associated gas is gathered throughout the Bakken well life cycle, then the well to wheel GHG emissions are estimated to be 89 g CO2eq/MJ (80% CI, 87-94) of Bakken-derived gasoline and 90 g CO2eq/MJ (80% CI, 88-94) of diesel. If associated gas is flared for the first 12 mo of production, then life cycle GHG emissions increase by 5% on average. Regardless of the level of flaring, the Bakken life cycle GHG emissions are comparable to those of other crudes refined in the United States because flaring GHG emissions are largely offset at the refinery due to the physical properties of this tight oil. We also assessed the life cycle freshwater consumptions of Bakken-derived gasoline and diesel to be 1.14 (80% CI, 0.67-2.15) and 1.22 barrel/barrel (80% CI, 0.71-2.29), respectively, 13% of which is associated with hydraulic fracturing.
authors.affiliation: Corporate Strategic Research, ExxonMobil Research and Engineering, Annandale, NJ 08801; ian.j.laurenzi@exxonmobil.com.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Laurenzi
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB Canada T2N 1N4.
authors.forename: Joule A
authors.initials: JA
authors.lastname: Bergerson
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB Canada T2N 1N4.
authors.forename: Kavan
authors.initials: K
authors.lastname: Motazedi
keywords: flaring; hydraulic fracturing; life cycle assessment; petroleum; unconventional resources