Shell produces 1,700 barrels of oil from Piceance shale
March 2, 2012
RIFLE, Colo. – The Shell Oil Company has produced 1,700 barrels of oil from its experimental oil shale project in the Piceance Basin, a company representative reported at the Northwest Oil and Gas Forum in Rifle on Thursday.
“So, we’ve successfully proven that our process works … on a small scale,” said Carolyn Tucker, a Shell community relations official based in New Castle.
The “oil” is a petroleum-like liquid derived from kerogen, which is a mixture of organic substances, locked in rock layers buried deep underground, that can be refined into fuel.
Shell, along with several other companies, has been researching the extraction of kerogen since the 1980s. The companies are working with federal agencies to determine how to unlock the energy from oil shale underlying the Piceance Basin.
The company has been working on its own privately held land in the Piceance Basin since 1996, Tucker said.
Historically, the methods used to extract the kerogen have involved mining the ore in which it is contained, transporting the ore to a “retorting” or heating plant to liquefy the kerogen and extract it from the rock, then refining the liquid for later use.
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Shell has developed a number of technological innovations, including an in-situ method that involves heating the rock in place, underground, and piping the resulting flow of oil up to the surface.
Shell also is working on a “freeze-wall” technology. This method surrounds the area to be heated with a wall of supercooled rock, to prevent contamination of nearby groundwater resources while the extraction process is underway.
Tucker said the 1,700 barrels of extracted oil came from a plot that was 30 feet by 40 feet at the surface, and roughly 1,800 feet deep, on Shell property.
The process, she told reporters, employed an “in-situ conversion” technology that sinks heating elements into the ground and heats the kerogen-rich rock layers to 260 degrees Fahrenheit. The kerogen is converted from its original solid form to liquid and gas, which flow to the surface.
The freeze-wall was used to isolate the process from the surrounding subterranean region, Tucker said.
Now, Tucker said, the company is about to begin a new phase of research, called the multi-mineral test. It will involve drilling 2,200 feet below the surface, lower than the level of known groundwater.
By working well below groundwater, she said, the company believes there will be no need to use a freeze-wall to prevent contamination.
The multi-mineral test, she continued, involves injecting warm water into deposits of nahcolite that occur alongside the oil shale layers. The water dissolves the nahcolite and the mixture is piped back to ground level. The resulting underground cavity creates a pathway for the compressed deposits of kerogen to flow to the surface once they have been heated.
The multi-mineral test will be conducted at one of Shell’s three leases on land controlled by the U.S. Bureau of Land Management. This will be the first test conducted by the company on public lands, she said.
The remaining two leases are for different phases of Shell’s oil shale development program, involving different aspects of the technology the company ultimately hopes will result in a commercial oil shale industry.
One lease, Tucker said, will be used to try out different types of heating elements to determine whether natural gas or electricity works best for heating the rock and converting the kerogen into liquids and gasses so it can be extracted.
Ultimately, Shell will combine different types of technology, such as the “freeze-wall” and the in-situ heating process, to attempt consistent and long-term extraction of the kerogen, she said.
In the meantime, the company is working with various levels of government, business communities and other interests to find ways to minimize problems associated with large-scale industrial initiatives in a rural setting.
“We’ve always said that we want to make oil shale be economically viable, environmentally responsible and socially sustainable,” Tucker said.
Western Colorado, in particular, has been through several boom-and-bust cycles related to energy development. These have included an oil shale boom in the late 1970s and early 1980s that, when the boom went bust in 1982, plunged the entire region into a recession.
“We’re really working behind the scenes, focusing on those socio-economic impacts,” Tucker added.