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 CO 2 eq/MJ (80% CI, 87-94) of Bakken-derived gasoline and 90 g CO 2 eq/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.life cycle assessment | unconventional resources | petroleum | hydraulic fracturing | flaring

Control of Sulfide Production in High Salinity Bakken Shale Oil Reservoirs by Halophilic Bacteria Reducing Nitrate to Nitrite

“…A key difference is that shale oil production can also require injection of water for continued oil recovery (Laurenzi et al, 2016). Flowback waters obtained from shale gas fields are highly saline (Daly et al, 2016; Khan et al, 2016; Shrestha et al, 2017), as are produced waters obtained from shale oil fields (Strong et al, 2013).…”

Influence of methane emissions on the GHG emissions of fossil fuels

“…In the first step, we calculated the specific GHG emissions of the primary energy consumption of crude oil and natural gas. In the next step, we calculated the final energy emissions and proceeded as follows: We took into account the diesel, gasoline, and natural gas final energy sources for end users. We assumed an average fossil primary energy factor (PEF) of 1.2 for the global diesel and gasoline mix over the entire scenario period, which we derived from various sources . The range of PEF in the studies scrutinized ranges from 1.9 to 1.3.…”

“…• We assumed an average fossil primary energy factor (PEF) of 1.2 for the global diesel and gasoline mix over the entire scenario period, which we derived from various sources. 64,[73][74][75][76][77][78][79] The range of PEF in the studies scrutinized ranges from 1.9 to 1.3. The lowest value is the PEF for diesel of the Standard Assessment Procedure (SAP) of the British government, the highest value being the PEF for gasoline in the USA of the GREET model.…”

Life-Cycle Assessment (LCA) of Different Pretreatment and Product Separation Technologies for Butanol Bioprocessing from Oil Palm Frond

“…Although burning biomass emitted higher CO 2 , N 2 O, and CH 4 when compared to burning natural gas, the total GWP of the plants were substantially lower than those using natural gas in CHP system since biogenic CO 2 is not considered in GWP impact calculation. The well-to-tank GHG emissions of gasoline were reported in the range of 0.016-0.026 kg CO 2 eq./MJ butanol [56][57][58]. The GWP profiles that were recorded while using this option (100% biomass-fueled CHP), for most of the pretreatment and product separation approaches were below those values (Table 12), potentially giving total lower GHG emissions when further including the fuel products combustion, which could indicate the environmental preservation potential of the biobutanol produced.…”