Photo credit: Flickr/Melissa 

It is estimated that there are 160 billion barrels of oil still trapped underneath this country in what are considered depleted oil fields. That's a tremendous amount of oil given that America uses about seven billion barrels of it each year. In fact, if we could only find the key to unlock this trapped oil we could extend fleeting our reserves by more than 22 years.

That's why it probably comes as a surprise to learn that we've already found the key we need to unlock this oil. That key is none other than discarded carbon dioxide, with the primary source of this practically prized greenhouse gas coming from none other than coal emissions. It's a stunning turn of events to say the least.

Cleaner coal and more oil, too
America has actually been flooding depleting oil fields with carbon dioxide since the 1970's. Most of the carbon dioxide used has come from naturally occurring sources. The problem is that carbon is costly as getting it from those sources to spent oil fields requires pipelines. But thanks to technological advances in carbon capture and storage we're beginning to see new investments that are directed to cleaning coal and using the captured carbon to produce more oil. It's this combination that has the potential to breathe new life into some of America's long dormant oil fields. 

A positive forward was taken when NRG Energy (NRG 1.85%) announced earlier this week that it began construction on a billion dollar retrofit to its East Texas coal-fired power plant. While the project is being underwritten in part by $167 million from the Department of Energy, NRG Energy sees it being self-liquidating as the carbon dioxide that is captured will be used to yield a 30-fold increase in oil production from an aging oil field NRG Energy also co-owns.

The reason production will surge is because carbon dioxide, which is injected into an oil reservoir, mixes with oil droplets that are left behind after initial production and expands the oil so that it can move through producing wells. The following slide shows how the oil recovery process works.

Source: Denbury Resources Investor Presentation (link opens a PDF

NRG Energy expects this process will improve the production at its West Ranch oilfield from a meager 500 barrels of oil per day to 15,000 barrels of oil per day at its peak. Put another way, at current oil prices that field will go from producing about $18.2 million worth of oil each year to well over half a billion dollars of black gold per year.

Meanwhile, the project will also substantially clean up the carbon emissions of NRG Energy's coal plant. About half of the flue gas that would typically be emitted into the atmosphere will go into the carbon capture facility, which will remove all of the sulfur as well as capture about 90% of the carbon. Because of that it will remove the equivalent of the exhaust of 336,000 cars each year.

Small steps
NRG Energy isn't the only company seeking to use captured carbon to clean up coal and fuel oil production. Denbury Resources (DNR) is building its business completely around the enhanced oil recovery process. So far the company has produced over a hundred million barrels of oil through carbon flooding. However, it is investing to build out the necessary carbon dioxide transportation infrastructure to revive even more nearly dead oil fields.

While most of Denbury Resources investments have been to take naturally occurring carbon dioxide to these fields, the company is beginning to use more industrially produced and captured carbon in its Gulf Coast operations as noted on the slide below.

Source: Denbury Resources Investor Presentation (link opens a PDF

As that slide points out, Denbury Resources currently has three projects either currently producing or pending start-up. The most important is the upcoming Mississippi Power project from Southern Company (SO 0.80%). The $5.2 billion power plant is the first large-scale plant in America that will transform coal into a gas, capture the carbon, and then sell it to Denbury Resources for enhanced oil recovery. If successful, Southern Company's plant should supply Denbury Resources with about 115 MMcf/d of carbon dioxide. Overall it is expected that the carbon captured from Southern Company's plant will be used to boost oil output by two million barrels per year.

Investor takeaway
There is an incredible amount of oil stranded in America in what are currently thought to be depleted oil reservoirs. But by using carbon dioxide captured by coal power generation, the energy industry will could breathe new life into these oil fields and revive production. It's a stunning turn of events that can provide Americans with cheap and cleaner coal-fired electricity as well as enough oil to get our nation off of OPEC's oil.