Monday, December 10, 2012

Gas, Oil, and Electricity from Oil Shale Kerogens Using In Situ Solid Oxide Fuel Cells

Trillions of barrels of oil equivalent locked inside oil shale kerogens are waiting for a clean and profitable approach of production. We have discussed one likely approach -- high temperature gas cooled nuclear reactors -- which is likely to be an effective, clean, and profitable approach to oil shale kerogen production. But it is likely to take between 15 and 20 years of development before such a method is ready for the Green River formation in the US Rocky Mountain west.

A different approach was patented by Marshall Savage, utilising solid oxide fuel cells (SOFCs) placed within the rock at strategic locations. This approach would produce oil, gas, and electricity using an in situ process, without significant mining or rock removal.
The present invention is a subterranean heater composed of fuel cells. In the preferred embodiment, the apparatus comprises a plurality of fuel cells assembled in a vertical stack via plates generally referred to in the art as “interconnect plates”, or “bipolar plates”. Conduits throughout the stack supply the cells with fuel and air or other oxidant, and remove exhaust gases. Preferably, the fuel cell stack is enclosed in a casing adapted for insertion into a well bore. An electrical connection is provided to the far end (typically bottom) of the stack to allow completion of an electric circuit.

The encased fuel cell stack is inserted into a wellbore, preferably vertically, but potentially horizontally or at some other orientation. Preferably, the encased stack is cemented into the borehole by a suitably heat conducting grout. Fuel and air are pumped into the stack through the incorporated conduits to the fuel cells. Within the fuel cells, electrochemical reactions take place to produce electricity and heat. The electricity passes out of the stack through an electric circuit. Fuel cells, of the solid oxide type, which are preferred, operate at temperatures in the 800 to 1000 degree Centigrade range. This is also the preferred temperature range for many subterranean heating applications. Heat passes from the fuel cell stack to the underground formation by thermal conduction. Thus, the operating fuel cell stack acts as a down-hole conduction heater of enormous magnitude, perhaps taking a year of operation to prepare a resource layer for in situ mining.

In the preferred embodiment of the invention, conduits for air, gaseous fuel, and exhaust are formed by aligning holes in the interconnect plates. Communication for circulation of these gases is provided by channels formed in the surface of the interconnect plates. _PatentsOnline

A small Colorado company is moving ahead with testing and development of this in situ fuel cell approach -- called Geothermic Fuel Cells because they put heat into the rock rather than taking it out.
A little-known energy technology company in Parker... stands at the forefront of a new era in domestic energy production. Independent Energy Partners Inc. is in the early stages of rolling out an industry game-changer, a device that holds tremendous promise in helping the United States harvest energy in a cost-effective and environmentally friendly way.

The seven-employee firm with offices on Pine Drive is about to turn the oil shale industry upside down with its in-situ Geothermic Fuel Cell, a solid oxide fuel cell unit that heats subterranean rock formations to recover three energy components from “unconventional hydrocarbons,” said Al Forbes, chief executive officer of IEP.

The first, accounting for roughly two-thirds of the recovered hydrocarbon energy, is a high-quality oil from the processing of kerogen in the shale. The second is natural gas. The third is “baseload green electricity,” captured via the “electrochemical process” of fuel cells. The electricity is produced as a by-product of the process, with nearly 80 percent being surplus and sold to utility or industrial companies, which offsets some of the costs associated with the process and the manufacturing of the high-tech Geothermic Fuel Cells.

Perhaps the most exciting aspect is that the unit is designed to operate on a portion of the gases produced during the process, resulting in a low carbon footprint, especially when compared to antiquated methods that are still being used. The GFC becomes a self-sustaining device that requires only a small amount of natural gas to start the process.

After getting patents, IEP worked closely with the U.S. Department of Energy’s Pacific Northwest National Labs on design and engineering to confirm the “technical feasibility” of the Geothermic Fuel Cell. IEP has also entered into agreements with Total Petroleum and the Colorado School of Mines, which has contributed technical support and will help conduct testing.

The partners have leases or options on oil shale resources in the Rocky Mountain Region that contain an estimated 16 billion barrels of oil; IEP owns mineral rights in the Piceance Creek Basin on the Western Slope that contain roughly 2 billion barrels of oil.

The low-emission process was developed by Marshall Savage, who approached Forbes with his idea in 2003. The founder of IEP was so convinced that the “revolutionary” product would succeed, that he dropped all other business ventures, including renewable energy, to strictly focus on the GFCs.

...The company, alongside the Colorado School of Mines, has begun an 18-month program to test the prototype prior to field demonstration, and Delphi has reconfigured some of its products to adapt to IEP's application. Forbes expects commercial production of GFCs by 2015 or 2016. _ColoradoNews
IEP's website

PDF comparison of oil shale production technologies, including a good look at the Geothermic Fuel Cell approach (PDF)

The in situ SOFCs are fueled by gas that is released from the rock once the fuel cells have warmed up. In other words, the process is self-sustaining once the SOFCs achieve operating temperature using an initial startup boos from natural gas.

The combined products of electric power, gas, and oil, provide the operation with multiple sources of cash flow.

Warm-up time required before commercial oil production can begin is estimated to be up to 2 years.

The total oil equivalent in the Green River kerogen deposit is estimated to be up to 3 trillion barrels.

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Blogger Unknown said...

Interesting idea, but it seems like they would have trouble competing with the efficiency and efficacy of just using directly burning the gas downhole. If the SOFC is 50% effcient, then half the heat is being sent out in the form of electricity. Obviously this will limit the amount of heat transferred to the rock. Less heat=less heated rock=less total oil production. Also nat gas burns at 1600 degrees instead of the 800 an SOFC operates at. Less temperature=slower heating=more gas burned on startup. Also building a downhole mini refinery to give the SOFC the absolutely pure fuel required for its operation will be an incredible technical achievement, should they succeed.

So if it all works, they need to be able to get enough money from the sale of the electricity to pay for the cost of the SOFC and all the gas from the 2 year startup and the cost of producing a well whose URR is only half of what it would otherwise be. Good luck to them though!

2:58 PM  

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