The GFC system consists of a string of 30ft GFC modules threaded together as they are installed down in the borehole. Each GFC module is made up of an interconnected series of fuel cell stacks contained within a robust oil field casing. The stacks are fed from the surface by common fuel, air and exhaust lines. The electrical power is collected at the surface and used to support the electrical needs of the operation. All surplus electrical power is sold to the nearest utility.
Applying GFC technology to oil shale recovery allows a more conventional oil and gas development approach. There is no mining required and the field consists of heater and production wells and the piping and controls necessary for operation. The heater wells are arrayed in a hexagonal pattern with a production well in the middle. There are approximately 2.3 heater wells for each production well. Conventional installation equipment and techniques are used to drill and case the wells and install the GFC modules.
Solid Oxide Fuel Cells become active at about 650ºC. The start-up procedure consists of supplying hot fuel and air to the fuel cell stack to heat it up until the cells become active. Once the cells are active, they will produce heat and electricity and accelerate the warm up cycle. This process will start at the top of the stack and continue until each stack is operating at the correct temperature. The start up process will take place over several days.
Initially, the fuel for the GFCs must come from an external source, such as the natural gas pipeline. Once production begins, non-condensable gases will be collected, cleaned, process and used to continue the operation of the GFCs. Eventually, the GFCs will become self-fueling and surplus gases will be sold to the market.
Yes. The non-condensable gases collected from the production wells will need to be reformed at the surface to breakdown the higher hydrocarbons into methane and CO to maintain efficient performance of the GFC system.
Coking will be prevented by ensuring that the GFC system is running at the optimal temperature and controlling the ratio of steam to carbon in the fuel stream.
Yes. While the GFC system is based on sulfur tolerant fuel cells, a de-sulfurization system will be in place to remove as much sulfur as possible.
Fuel cells are one of the cleanest ways to produce electricity and heat. Depending on the fuels used, the byproduct is water and CO2. Since the exhaust is captured, the CO2 is also captured and stored. Water that is generated from the process is captured and used to support the production operation, which minimizes the need for external water.
The in-situ application of GFCs is the cleanest way to recover oil and gas from unconventional hydrocarbons, such as oil shale and tar sands. Since the conversion takes place underground and the oil and gases are collected from sealed wells, there are virtually no emissions from the production process.
Additional benefits include, no mining, no shale waste disposal, no green house gas emission from the process, or from the power generation and minimal disturbance to the land.
Geothermic fuel cells use much less water than alternative shale oil production processes. A comprehensive recent study of water needs by the Colorado River Basin Roundtable showed a range of possible water consumption of between 2.2 and 4.6 barrels of water per barrel of shale oil. Between .8 and 1.6 barrels of this amount is for spent shale disposal, which is not needed for our true in situ process. Another .17 to .26 barrels are needed for electrical generation, which we do not need since we produce our own electricity. Other items in the water use bill are not fully applicable, for example: .11 to .46 barrels for population. This certainly should not apply to any of the population that already lives in Colorado, since these people already consume water and do not require additional supplies. Other water intensive activities, like shale oil upgrading, .6 to 1.6 barrels, will probably occur in other states and will draw on other water resources. Taken altogether these reductions in Colorado water usage will result in consumption of between 1 to 2 barrels of water per barrel of oil produced by geothermic fuel cells.
A huge oil shale production industry based on geothermic fuel cells might produce a million barrels of oil per day. At 2 barrels per barrel this would consume less than 100,000 acre-feet of water per year.
In addition to stream flows there is also a vast reserve of ground water in the Piceance Creek Basin underlying the oil shale formation. This aquifer may contain more than 20 million acre-feet, enough water to sustain a giant oil shale industry for 200 years.
In our geothermic process ground water is first removed from the target formation through a process called “dewatering”. The dry formation can then be heated. As part of dewatering the formation is cut off from ground water infiltration with underground dams called “grout curtains”. After shale oil has been removed and the remaining char has been gasified for additional energy recovery, the formation is secured and left dry. This is accomplished through a combination of processes.
The first line of defense is complete surface reclamation through a process called “phytoremediation”. Phytoremediation involves planting a dense community of trees, shrubs, and grass, on the surface overlying the treated formation. As the plant community grows if forms an increasingly dense network of roots in the topsoil. These roots absorb moisture, which is then filtered through the plant’s metabolism and is then released to the atmosphere through plant respiration. Phytoremediation reduces water infiltration into the underground by 90%. Typical rates of percolation into the subsurface in the Piceance Basin are less than an inch a year. Phytoremediation will reduce this to less than a tenth of an inch. If nothing else were done, it would require over a hundred years to accumulate one foot of water in the dry aquifers. The dry oil shale formation in the Piceance will be over a thousand feet thick.
Through use of guard wells and addition of grout curtains, and possibly the installation of drainage passages under the formation, water will be entirely prevented from accumulating in the treated zone. Water removed from the formation either through guard wells or through the drainage system will be monitored for pollutants and treated to drinking water standards prior to being released into streams or being re-injected into the existing aquifers. In any case the process will be carried out by methods that prevent any degradation of ground water quality.
Each application is different, depending on the energy content of the resource. In the case of oil shale, we estimate that once the GFCs are started up, it will take approximately 6 years to recover all the energy from the oil shale. This includes the oil, non-condensable gases and the gasification from the residual char from the shale.
The GFC system provides two significant advantages: economic and environmental. Selling surplus electricity and gas significantly offsets the cost of oil and gas recovery. Producing and using “green” electricity and recovering the oil and gas in-situ, while generating very little environmental waste overcomes a significant hurdle to unconventional hydrocarbon recovery today.
No. Shale oil recovered using an in-situ process has much more desirable properties than conventional surface retorting. By controlling the time and temperature, the oil recovered has a relatively high API and eliminates most of the upgrading requirements compared to surface retorting.
Synthesis gas or syngas is a gas mixture containing various amounts of hydrogen and carbon monoxide. It is a very useful industrial gas. It is used as a reaction intermediate to produce synthetic natural gas and it can be used to produce liquid fuels.