This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Energy efficiency is widely touted as one of the best ways to reduce both the cost and environmental impact of energy production. It's well known that building efficiency strategies like replacing incandescent light bulbs with compact fluorescent or LED bulbs can reduce energy consumption and emissions and save consumers money over time.
Now the emergence of hydraulic fracturing and the resulting boom in U.S. oil and gas production has created a new opportunity for energy efficiency: capturing waste natural gas that otherwise would be flared on site.
The recent hydraulic fracturing boom has led to a surge in oil and gas drilling in areas that weren’t conventionally major centers of production. Most notably, North Dakota’s Bakken region and Texas’ Eagle Ford region have grown to comprise nearly half of total U.S. oil production.
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While the Bakken and Eagle Ford Regions produce about half of the total U.S. oil supply today, they haven’t traditionally been major producers of oil and gas. It wasn’t until after 2011 that these areas began producing a significant share of the U.S. oil supply.
Because the Eagle Ford and Bakken regions just recently became major areas of oil production, they don’t have the oil and gas pipeline infrastructure that more established regions like Texas’ Permian basin do. This isn’t a huge problem for oil, which can be delivered from the wellhead to market using a combination of trucks and trains. However, there are no practical ways to move natural gas to market without pipeline infrastructure in place. This means that producers in the Eagle Ford and Bakken region are often forced to simply burn any natural gas released as a product of oil production on site. Note that natural gas is flared to prevent the release of methane — a far worse greenhouse gas than carbon dioxide.
Limited natural gas pipeline infrastructure has lead to significant flaring of natural gas produced as a byproduct of oil production in the Bakken and Eagle Ford regions. (Source: NASA Earth Observatory/NOAA NGDC via EARTH Magazine)
The result of all this natural gas flaring is lots and lots of wasted energy. According to the most recent data from the U.S. Energy Information Administration, the United States vented or flared over 288 billion cubic feet of natural gas in 2014. That’s about 296 million MMBtu (MMBtu = million British thermal units) of energy based on the average heat content of U.S. natural gas in 2014. Even at today’s relatively low natural gas prices of about $2 per MMBtu, the amount of vented or flared gas in 2014 amounts to nearly $600 million in wasted resources. If all of that wasted gas were burned in a modern combined-cycle power plant, it would produce over 38 billion kilowatt-hours of electric energy, or enough to power over 3.5 million average U.S. households.
Fortunately, solutions to the flared gas problem are already emerging. Oil and gas drilling operations often use on-site diesel generators to produce electricity required for lighting and other oilfield equipment. A number of companies have started offering natural gas generators that can run off of wellhead gas that would normally be flared, displacing diesel consumption and reducing net emissions.
Another emerging issue that flared gas could be used for is on-site treatment of hydraulic fracturing wastewater. Today, most wastewater that flows back from hydraulically-fractured oil and gas wells is disposed of at deep-well injection sites. Due to the high volumes of wastewater produced by the hydraulic fracturing boom, deep-well injection has led to increasing earthquakes in regions like Oklahoma and Texas. Flared natural gas could be used as an energy input for a variety of wastewater treatment methods that could produce freshwater from fracking wastewater, helping to not only reduce the issues associated with oil and gas wastewater, but also increase the overall water supply.
Ultimately, the best solution to wasted natural gas in the form of flaring is to expand natural gas pipeline infrastructure in the Bakken and Eagle Ford regions. That way, produced natural gas could be delivered to the wider natural gas transmission network and delivered to power plants and households rather than wasted.
There is an enormous amount of energy being wasted in the form of flared natural gas. The emissions and heat output from a natural gas flare flow straight to the environment without providing any useful function. We can do better than that. Let’s implement the solutions and infrastructure needed to improve the energy efficiency of the natural gas supply chain.
Agenda image credit: Jared Garrison, with permission.
