Oil companies are burning money by flaring off the gas produced in oil extraction. North Dakota, one of the worst offending states, is cleaning up its act
SEEN from space at night, the thinly populated state of North Dakota could be mistaken for a major metropolis. But the bright lights aren't the glow of streets and homes. They are flames from billions of litres of natural gas being burned, a by-product of the booming oil industry. Now, under pressure from regulators, technologies are emerging to help harness that wasted resource.
Economics drives the waste. Oil production from North Dakota's Bakken shale quadrupled between 2010 and 2014. The volume of gas that belches up with the oil followed in step, faster than oil companies could build infrastructure to pipe it away. Too impure to generate power on site, and too light for train cars to haul a worthwhile amount to market, the gas presented oil companies with an unprofitable problem. So they burned it.
"It was worth it to just put the gas up in smoke," says Joseph Palaia of Colorado oil technology company Pioneer Energy. He says the oil was 10 times more valuable than the gas that came with it, so capturing the gas didn't make business sense.
Now, as states adopt stricter emissions standards, that's starting to change. Energy companies and start-ups are finding ways to capture and make use of the gas, reducing carbon emissions and increasing efficiency.
The problem is huge. In 2014, about 26 per cent of gas produced in North Dakota was flared off – 10 million cubic metres of fuel a day, emitting about 21 tonnes of carbon dioxide. This is compared with the rest of the US, which only flares 1 per cent of its natural gas on average. But merely venting the gas would be worse than burning it, because its primary component, methane, traps heat in the atmosphere more effectively than CO2.
In July 2014, North Dakota's Department of Mineral Resources took action, issuing a state order for the reduction of flare gas. California-based company Ener-Core has one solution to make use of the waste product. Its technique involves pressurising the gas, which forces it to start reacting with oxygen. This reaction produces heat, which is then used to drive a turbine and produce electricity.
The system was originally designed to work with any source of waste gas, so Ener-Core is running its first flare-gas test facility at the University of California, Irvine. The company plans to sell units to oilfields in the next three years. The generators are designed to replace the diesel generators that oil rigs currently rely on to power their operations.
Pioneer has a different approach – a huge refrigerator, mounted on the back of a truck, which it calls a Mobile Alkane Gas Separator (MAGS). In this, flare gas is compressed and dehydrated, before being cooled and separated into its component hydrocarbons. The methane is used on site to generate electricity and the heavier hydrocarbons are shipped away for sale. Pioneer deployed its first MAGS unit in North Dakota last November.
General Electric has a similar system, a 12-metre trailer that compresses and separates gases. GE installed its system at a Bakken shale well run by Statoil last year. Statoil estimates the system captures between 80,000 and 140,000 cubic metres of flare gas a day. The produced methane is used to run trucks on site and Statoil says it has already commissioned a second unit for its Bakken operation.
Time is of the essence. Wells produce the most flare gas when they are new, says Chad Wocken, senior research manager at the Energy & Environmental Research Center at the University of North Dakota. For every new well without this technology, companies like Statoil are burning money, and needlessly pumping carbon dioxide into the atmosphere.
The technology for harnessing flare gas might be clever, but flaring would never have become a problem if regulation around the boom had been tighter.
"It's not a failure of technology, but of regulation," says David McCabe, an atmospheric scientist at the Clean Air Task Force in Boston. If the current rules had been in place from the beginning, oil companies would have had to build adequate pipeline capacity to ship the flare gas out.
They may have taken the long way round, but North Dakota's oil companies are finally reining in their wasteful behaviour. By 2016, the state aims to have cut the amount of flared gas down to 15 per cent. Soon, astronauts on the International Space Station should be able to stop mistaking the Bakken shale for a city.
This article appeared in print under the headline "Fighting flares"
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