By Patrick Rucker
WASHINGTON Jan 2 Crude oil produced in North
Dakota may be more flammable and prone to explosions than
earlier thought, U.S. officials said on Thursday as they examine
whether gas trapped in crude-by-rail shipments could explain a
spate of fiery accidents.
In the latest mishap involving fuel produced in an oil patch
known as the Bakken, several tank cars exploded after a
collision on a desolate stretch of North Dakota track on Monday.
In that case, as with several other accidents in recent
months, tank cars exploded with a force that surprised
The incidents "indicate that the type of crude being
transported from the Bakken region may be more flammable than
traditional heavy crude oil," the U.S. Pipeline and Hazardous
Material Safety Administration said on Thursday.
Officials are examining whether Bakken crude is unduly
corrosive, more sulfurous or loaded with explosive gas as it
moves on the tracks from oil fields to distant refineries.
On Thursday, Bakken producers were warned to "sufficiently
degasify" crude oil being loaded onto tank cars, and officials
said they will examine the "dissolved gas content" of crude oil
Packing gas onto tank cars meant to carry liquid fuels can
push the pressure to dangerous levels and provoke explosions,
industry officials have said.
"Large amounts of vapor pressure can split the tank, sink
the roof and emit (a) flammable gas cloud," the Canadian Crude
Quality Technical Association, an industry-sponsored research
group, concluded in March.
Bakken producers have recently reported a large amount of
corrosion in tank cars and "high vapor pressure causing bubbling
crude," the trade group said.
Advances in drilling technology have dramatically spurred
oil production in North Dakota in recent years. Over two-thirds
of the state's oil production is currently shipped by rail.
Trains carried nearly 700,000 barrels a day of North Dakota
oil to market in October, a 67 percent jump from a year earlier,
according to the state pipeline authority.
Officials are considering new rail safety rules for crude
shipments in light of several spectacular accidents in the
United States and Canada.
In July, a runaway oil train carrying light shale crude oil
from the Bakken region derailed and exploded in the center of
the Quebec town of Lac-Megantic, killing 47 people.