期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：48
页码：E7672-E7680
DOI：10.1073/pnas.1607475113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceThe growth of production from tight oil plays such as the Bakken and Eagle Ford has prompted public interest in understanding the greenhouse gas (GHG) emissions and freshwater consumption associated with these resources, specifically with regard to hydraulic fracturing and flaring. Therefore, we conducted a comprehensive life cycle assessment of Bakken crude, using thousands of data from XTO Energy and other Bakken operators, establishing robust estimates of the footprint of current production practices. We conclude that flaring and hydraulic fracturing have a small impact on the life cycle (well to wheel) GHG emissions associated with Bakken and that these GHG emissions are comparable to those of other crudes. 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.
