Tapping a viable resource

A US Department of Energy-funded project has successfully demonstrated the viability of a new technology that could prove to be the key to unlocking America‘s largest potential source of oil.

If ongoing research continues to confirm the technology’s effectiveness, its application offers the potential to reduce costs and environmental impacts in the extraction of oil from oil shale.

Composite Technology Development (CTD), of Lafayette, Colorado, is developing a technology that can heat oil shale in situ, several thousand feet below the surface, separating the kerogen – a substance contained in shale that is thought to be a precursor to petroleum – without mining the oil shale rock. If proven viable, the process could extract the petroleum-like liquid and render it mobile enough to be pumped to the surface.

CTD’s project goal is to develop downhole cable heaters 2,000-5,000 feet long that can be deployed in oil shale deposits. These cable heaters would provide high power to heat the oil shale to about 850 degrees C (1,550 degrees Fahrenheit). There are two main challenges associated with developing this technology: producing electrical insulation material that is stable in the subsurface at high temperatures over time; and developing a cost-effective manufacturing method to fabricate the heaters.

In the first phase of the project, CTD developed and evaluated high-temperature ceramic-based composite insulation materials that meet the requirements of an in situ oil shale recovery process. Researchers also conducted 2,500 hours of tests of the performance of the new insulation materials in full-power, limited-length cable heater prototypes. The results: much improved insulating qualities that were stable over time when compared with commercially available products.

In the project’s second phase, CTD is developing and scaling up a manufacturing process to cost-effectively produce the new-design cable heaters in lengths relevant to an oil shale recovery system.

By eliminating the mining and large-scale processing aspects of oil shale development, such in situ technology could slash its recovery cost by half or more while minimising disturbance of the land.