Study: GHG from US-refined crude oils unchanged by Canadian oil sands
The growth in US imports of Canadian oil sands in recent years has not impacted the overall greenhouse gas (GHG) intensity of the US supply mix, according to a new study by global consultancy IHS.
The growth of oil sands imports were offset by substitution for similar sources of supply and by increases in lower-carbon tight oil displacing relatively higher carbon imports from Africa and elsewhere, the study says.
The new IHS CERA Oil Sands Dialogue study calculated the GHG intensity of the average oil sands refined in the US by estimating the mix of oil sands products pipelined to and refined in the US in 2012. This calculation is intended to provide a more up-to-date comparison of the products GHG intensity compared to other types of crude that are processed in the country.
The US oil supply mix has changed significantly since 2005, the year most commonly cited for comparisons, said Kevin Birn, a director at IHS Energy who leads the oil sands dialogue research. The dramatic increase in US tight oil supply has displaced comparatively higher carbon light crude oil from offshore, while a reduction in imports of other heavy crudes of a similar carbon intensity to oil sands has kept the overall GHG intensity of the US oil supply mix unchanged.
Imports of oil sands, synthetic crude oil and other Canadian heavy crude to the US grew by 75% or 900,000 bpd between 2005-2012 to more than 2 million bpd. That increase was offset by other changes to the US supply
mix during that time, the study says.
United States tight oil production
, which was nonexistent in 2005, has grown substantially. Tight oil production
reached 1.8 million bpd in 2012 accounting for 30% of US domestic supply
. That growth has displaced similar light sweet crudes from Africa and elsewhere that were on average relatively higher carbon.
At the same time, the rise in oil sands imports was offset by declines in imports of other heavier sources of supply
that have a GHG intensity within the same range as oil sands, the study says. 2012 imports of heavy crude from Venezuela and other sources from Latin America declined by 400,000 bpd compared to 2005. Imports from Mexico declined by nearly 600,000 bpd during that same period.
The IHS study also finds that, taking into account the recent changes to the US oil supply mix, refined products from Canadian oil sands have well-to-wheels life-cycle GHG emissions that are between 1% and 19% higher than the average crude oil consumed in the US in 2012. This places oil sands within the same GHG intensity range as 45% of the crude oil supplied to US refineries in 2012.
Oil sands are often singled out for having higher GHG emissions than other sources of UScrude, Birn said. But the more recent data
shows that crude oil from the Canadian oil sands is within a GHG intensity range of nearly half the crude oil supplied to US refineries.
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