Making Oil-by-Rail Safer

• A series of rail accidents involving trains carrying crude oil has focused attention on safety procedures and even the tank cars used in this service.
• Another concern is the variable characteristics of the "light tight oil "now shipped by rail in large quantities. That isn't the result of "fracking", but of the oil's inherent chemistry.   

The growth of North American oil production from unconventional sources has resulted in a dramatic expansion in the volume of crude oil shipped by rail. Unfortunately, as crude oil rail traffic has increased, so have rail accidents involving crude oil, including the tragic explosion and fire in Lac-Megantic, Quebec last July. That event and subsequent accidents have focused railroads, regulators and shippers on the need to improve the safety of oil-by-rail as quickly as possible.

In the immediate aftermath of Lac-Megantic, the Federal Railroad Administration issued an emergency order on procedures railroads must follow when transporting flammable and other hazardous materials. And on February 21, 2014 railroads reached a voluntary agreement with the US Department of Transportation (DOT) on additional steps, including reduced speed limits for oil trains passing through cities, increased track inspection, and upgraded response plans. These steps have the highest priority, because crude oil loaded in tank cars doesn't cause rail accidents. Every incident I've seen reported in the last year began with a derailment or similar event.

At the same time, the packaging and characteristics of the oil can affect the severity of an accident.  Investigators have focused on two specific issues in this regard, starting with the structural integrity of the tank cars carrying the oil. The vast majority of tank cars in this service are designated as DOT-111--essentially unpressurized and normally non-insulated cylinders on wheels. These cars routinely carry a variety of cargoes aside from crude oil, including gasoline and other petroleum products, ethanol, caustic soda, sulfuric acid, hydrogen peroxide, and other chemicals and petrochemicals.

Their basic design goes back decades, and even the older DOT-111s incorporate learnings from earlier accidents. A growing proportion of the US fleet of around 37,000 DOT-111 tank cars in oil service consists of post-2011, upgraded cars that have been strengthened to resist punctures, but the majority is still made up of older, unreinforced models. The Pipeline and Hazardous Materials Safety Administration (PHMSA) is studying whether to make upgrades mandatory, but some railroads and shippers aren't waiting. Last month Burlington Northern Santa Fe Railway, owned by Warren Buffet's Berkshire Hathaway, announced it would buy up to 5,000 new, more accident-resistant tank cars.

Another issue that has received much attention since Lac-Megantic concerns the flammability of the light crude from shale formations like North Dakota's Bakken crude, which accounts for over 700,000 barrels per day of US crude-by-rail. The Wall Street Journal published the results of its own investigation, reporting that Bakken crude had a higher vapor pressure--a  measure of volatility and an indicator of flammability--than many other common crude oil types.

The Journal apparently based its findings on crude oil assay test data assembled by the Capline Pipeline.  Although a Reid Vapor Pressure of over 8 pounds per square inch (psi) for Bakken crude is higher than for typical US crudes, it's not unusual for oil as light as this. That's especially true where, due to lack of field infrastructure, only the co-produced natural gas is separated out, leaving all liquids in the crude oil stream.

What makes this situation unfamiliar in the US is that domestic production of oil as light as Bakken had nearly disappeared before the techniques of precision horizontal drilling and hydraulic fracturing were applied to the Bakken shale and similar "source rock" deposits. (Note: High vapor pressures are characteristic of the naturally-occurring mix of hydrocarbons in very light crudes, rather than a result of the "fracking" process.) Nor is the reported vapor pressure for Bakken or Eagle Ford crude higher than that of gasoline, a product that is federally certified for transportation in the same DOT-111 tank cars that carry crude oil.

The variability of the vapor pressure data that the Journal's reporters identified for Bakken crude may result from another unfamiliar feature of such "light tight oil". Crude produced from conventional reservoirs, which are much more porous than the Bakken shale, tends to be relatively homogeneous. However, because the Bakken and other shales are so much less porous, limiting diffusion within the source rock reservoir, the composition of their liquids can vary much more between wells.

In any case, vapor pressure isn't the preferred measure of fuel flammability. Actual rail cargo classifications are based on flash point and initial boiling point. These routine quality tests aren't included in Capline's publicly available data. PHMSA initiated "Operation Classification" to ensure that manifests and tank car placards for crude oil shipments accurately reflect the potential hazards of each cargo, based on such measurements. The agency has determined that it hasn't always been done consistently, and DOT issued another emergency order requiring shippers to test oil for proper classification.

As mentioned in an oil-by-rail webinar yesterday, hosted by Argus Media, assigning the proper classification to oil shipments may seem like a bureaucratic concern--it doesn't necessarily affect the tank car type chosen to transport the crude--but it can have a significant impact on operational factors such as routing and the notification of first responders along the route.

There's no quick and simple way to make the transportation of crude oil by rail as safe as hauling a dry bulk cargo like grain. Tank car fleets can't be replaced overnight, not just because of the cost involved, but due to limited manufacturing capacity. However, in the meantime significant improvements can be achieved through a combination of government attention and sustained industry initiatives. Since the new crude streams traveling by rail play a key role in increasing North America's energy security, this is in the interest of everyone involved--producers, shippers, railroads, and not least the communities through which this oil travels.

A different version of this posting was previously published on the website of Pacific Energy Development Corporation.
 

Do Crude Oil Shipments Make Rail Less Safe?

• The movement of crude oil by rail is expanding rapidly but still represents a small fraction of the hazardous goods transported by rail in North America.
• The devastation caused by an oil train accident in Lac-Megantic, Quebec should galvanize railroads, shippers and regulators to improve rail safety for all hazardous freight. However, it does not justify banning oil-by-rail.

It’s been nearly two months since a train loaded with crude oil from North Dakota derailed and exploded in the Canadian town of Lac-Megantic, Quebec, killing an estimated 47 residents. In the interval since the accident, the relevant authorities have focused on ascertaining the cause of the accident and determining how best to improve rail safety. However, there has also been another, less-customary conversation about whether oil in general, and the specific oil on this train, might be too dangerous to transport by rail at all. That conversation would benefit from some context that appears to be absent.

Both conversations began with a tragedy in a place I recognized immediately. Ten years ago my wife and I passed through Lac-Megantic and drove along the Chaudière river that originates there, on its way to the St. Lawrence. It’s an area of natural beauty and historical significance. The images of destruction and of oil spilled in the river were gut-wrenching.

The investigation is still underway, but it seems significant that the Federal Railroad Administration (FRA) of the US Department of Transportation has already issued an Emergency Order banning the practice of leaving such trains unattended, pending the development of better procedures for securing them safely. Canadian authorities are reviewing their regulations and enforcement, as well as revisiting questions about the specific type of tank car in which the oil was carried. The Wall St. Journal reported that the FRA is also  looking into the testing and classification of crude oil shipments, to ensure that the tank cars used to transport different crude oils are suited to the task. Meanwhile, the rail operator involved in the accident has filed for bankruptcy on both sides of the border.

The second conversation, apparently based on a belief that it is possible to cease our use of petroleum entirely if we only have the will, is occurring in a fact vacuum. Understanding why that particular batch of crude oil was on that specific track on that day requires unpacking a nested set of factors that starts with the fact that oil still accounts for 33% of total global energy consumption, but more importantly supplies 93% of transportation energy. Numerous forecasts, including the latest from the US Department of Energy, anticipate no reduction in global oil use through 2040. Although we’ve displaced much of the oil formerly used to generate electricity and have greatly improved vehicle fuel efficiency, our most successful alternative transportation fuel, ethanol--no stranger to rail accidents--accounted for just 3% of US liquid fuel use last year, when adjusted for its lower energy content.

Although global oil movements are dominated by pipelines, tankers and barges, rail remains an important mode because of its flexibility. It’s also usually cheaper and more efficient than trucking for all but short distances--and safer, too, despite accidents like this one. Although the rapid recent growth of crude-oil-by-rail and its role in the Keystone XL pipeline debate have attracted significant attention, last year’s 234,000 tank-car loads of crude made up less than half of total US petroleum rail shipments and were dwarfed by over 1.5 million tank-car loads of chemicals hauled by rail in 2012.

Crude oil, especially light crudes like those produced from the Bakken and Eagle Ford shales, is flammable, and thus constitutes hazardous cargo. However, railroads routinely carry a wide variety of flammable and otherwise hazardous materials, including propane, gasoline, benzene, ethanol, chlorine gas, sulfuric acid and a range of other chemicals. Safety is not  determined by the cargo--if it was, none of these substances would be on trains--but by the combination of the equipment used to carry it, the rules and processes that dictate how to handle it, and the people who operate these systems. It’s no coincidence that these are the areas on which the investigations and preliminary regulatory responses have focused.

Then there are the market and logistical circumstances that resulted in a St. John, New Brunswick refinery that supplies both Canadian and US consumers and normally processes oil imported by tanker, acquiring oil produced in North Dakota and shipped halfway across the continent by rail. North American oil production is expanding rapidly, with significant economic and energy security benefits. Much of this new oil is found in places not adequately served by the large network of existing pipelines. That situation may eventually be rectified, but in the meantime the mismatch between growing landlocked oil supplies and limited pipeline outlets for them has created an opportunity for rail operators reeling from the much larger shale-gas-induced decline in coal shipments. Serving that need keeps people and trains employed. And that, ultimately, is why a train carrying Bakken crude was on a track in Lac-Megantic this July.

I can scarcely imagine what the survivors of the Lac-Megantic disaster and the families of the victims have been going through for the last two months. Their lives will never be the same. But whatever the cause of the accident is determined to have been--human error, mechanical failure, aging infrastructure or something else--it was not caused by the oil in those tank cars.

In the aftermath of an accident like this, the best thing we can do is to determine why it happened and apply those lessons to make rail transport of all hazardous cargoes safer.  Attempting to use the tragedy to advance a social cause such as “ending our reliance on oil” might be alluring to some, but the communities through which such freight travels in the course of keeping our economy running will benefit much more from the former course of action.

A different version of this posting was previously published on Energy Trends Insider.