In a follow-on to its figures on rail movements of crude oil, ethanol and biodiesel, the U.S. Energy Information Administration has initiated a data series on rail movements of hydrocarbon gas liquids in its latest "Petroleum Supply Monthly" statistics.
The EIA now provides detail on HGL movements between and within Petroleum Administration for Defense Districts, or PADDs, as well as shipments to and from Canada, and uses figures provided by the U.S. Surface Transportation Board. The HGLs that are accounted for are propane, propylene, normal butane and isobutane.
Rail movements of these HGLs averaged 426 Mbbl/d from January 2016 through November 2016, according to a "Today in Energy" column published by the EIA on Feb. 2. That is just slightly below the amount of crude oil shipped by rail during the period, of 478 Mbbl/d.
Rail transportation of HGLs accounts for nearly a quarter of all inter-PADD movements, according to the agency, with pipelines serving as the primary mode of transport.
"We're not addressing ethane, ethylene or natural gasoline because we found that the quality of the data is not sufficient enough to warrant the presentation of that data in our tables," EIA analyst Warren Wilczewski said in a webinar on the topic Feb. 2.
The EIA released the data in its "Petroleum Supply Monthly" report published Jan. 31, and includes figures going back to 2010.
Shipments either from or within the Midwest PADD 2 play a key role in rail transportation of HGLs, with 2.9 MMbbl of propane shipped in November 2016. That included 1.1 MMbbl shipped within the PADD, with large portions likely from the Bakken to the storage hub in Conway, Kan. There were 647 Mbbl shipped from PADD 2 to PADD 1 in November 2016, while 684 Mbbl were shipped from PADD 2 to PADD 3 during the month.
"Propane leads other HGLs because it serves a variety of markets that are scattered across the country in remote areas where pipelines cannot reach," Wilczewski said. "Propane production is also the largest product in terms of gas plant liquids, so it leads the volumes of HGL by rail."
Commodities like normal butane represent smaller quantities of HGLs shipped by rail with only 1.0 MMbbl shipped within or outside of PADD 2 out of a total 3.5 MMbbl shipped either within the U.S. or in trading with Canada.
Butane shipments within PADD 5 are significant in the winter months, as the product tends to be shipped from facilities in Arizona to the southern California gasoline market. There were 637 Mbbl shipped in November 2016.
In the data that describes shipments to and from Canada, there were 2.3 MMbbl of propane imported from Canada in November 2016, while only 253 Mbbl were exported to the country.
The EIA has developed a methodology to review trade figures with Mexico, but it has not progressed enough to determine whether there is value.
"There is better data sharing with Mexico being undertaken," Wilczewski said. "We're hoping that as the data sharing agreement flourishes and the data improves, we will be able to validate the data we have, we will be able to add Mexico as a source into our tables."