A better way to tap the tar sands

In the desolate Canadian wilderness along the southwest edge of the Canadian Shield in northern Alberta and Saskatchewan, tens of millions of unforgiving acres contain the natural resource that spurs economies the world over--oil.

This oil, however, is known as the "tar sands" - a gluey mixture of land containing oil, tar and sand - and extracting it is expensive, inefficient and unfriendly to the environment.

One Baylor professor is helping to change that.

"Traditionally, tar sands mining has been a very difficult process with environmental consequences," Dr. Scott James, assistant professor in Baylor's Department of Geosciences, said. "The oil in the tar sands doesn't flow, so it takes steam to melt it deep below the surface. Previous methods to get the oil use a boiler to create steam at the surface, and you lose half of the energy and heat radiating out as it travels down-site. It's notoriously challenging, and the tar sands are considered depleted when just 5 percent of the oil is moved."

Since 2010, James has collaborated with R.I.I. North America, a Canadian company, to find a better way. The result is a method of enhanced oil recovery called down-hole steam generation, a self-contained system that increases the amount of oil extracted from 5 percent to 30 percent.

Beyond adding efficiency, it makes the process more environmentally sound by recycling waste products as valuable ingredients to extract the oil as opposed to releasing them into the atmosphere or disposing of them at great expense.

Down-hole steam generation does not require a boiler at the surface. A multi-chambered cylinder is lowered into previously drilled wells, which had been considered exhausted after 5 percent of the oil had been extracted. Methane and oxygen are injected into the cylinder, which produces carbon dioxide and water in the drill site. This creates steam deep below the surface rather than above, and it means the energy isn't lost on the way down.

"Once we've injected the methane and oxygen down-hole, it forms combustion products of carbon dioxide and water, like what comes out of your tailpipe," James said. “In this case, the carbon dioxide is a valuable product to us because it dissolves in the oil, allowing it to flow more freely. Whereas it used to be released to the atmosphere, we now inject it into the formation as a valuable product. Most of it is sequestered underground. That’s the beauty of down-hole steam generation. It's 100 percent thermally efficient and what was a waste product becomes a value-added product."

Other value-added products include the methane and saltwater byproducts of oil production. Methane typically is flared into the environment, similar to what drivers passing an oil refinery might see as an open flame amidst the pipes and towers. Down-hole steam generation captures that methane along with the saltwater that is produced.

"Instead of flaring methane," James said, "we use it as process fuel, piping it back down-hole and burning it. It's captured in one cylinder, with oxygen outside of it, which combine in a burner to blast a flame. To keep it all cool, we also capture the saltwater produced in a third chamber, which cools the shroud and creates the steam that keeps the oil flowing. It's completely self-contained and we have almost no waste product."

R.I.I. has named the process Solvent Thermal Resource Innovation Process, or "S.T.R.I.P." Now in its third pilot project, the greatest obstacles are logistical--finding materials capable of standing up to the intense environmental demands. The high pressure beneath the surface, combined with the presence of saltwater and high temperatures, have corroded stainless steels and other metals. R.I.I. uses an exotic metal called Hastelloy c 22, which can also be found in space shuttles, in the latest round of testing.

Along with James, Dylan Jiang is working on the project as the main focus of his Baylor geology doctorate studies. They hope to see a production-scale approach to materials needed for the S.T.R.I.P. process within the next two years.

"The technology is there, we're just fine-tuning it," James said. "A factor of six improvement in oil production is significant, especially when we're doing so in an environmentally friendly way. You're reinjecting saltwater you normally pay to dispose of, you're reinjecting methane you'd normally flare into the atmosphere and you're using it on wells that have already been drilled. This could be a game-changer for the oil industry, and for the regions around the tar sands who previously dealt with the environmental consequences."