A Cheaper Way to Draw Oil from Shale

A new ceramic-composite material that can withstand high temperatures and constant exposure to moisture could provide an economical way to unlock America’s vast oil-shale deposits.

More recently, companies such as Royal Dutch Shell have developed ways to tap the oil in situ, by drilling boreholes that are thousands of feet deep and feeding into them inch-thick cables that are heated using electrical resistance and that literally cook the surrounding rock. The kerogen liquefies and gradually pools around an extraction well, where the oil-like fluid can easily be pumped to the surface.
The process involves no mining, uses less water than other approaches, and doesn’t leave behind man-made mountains of kerogen-sapped shale. And according to a Rand Corporation study, it can also be done at a third of the cost of mining and surface processing. One technical hitch, however, lies with the heater cable employed. The most common cables used today are insulated with a layer of magnesium oxide, which can deform, degrade, and ultimately short out over time under intense heat, constant exposure to moisture, and the occasional shifting of rock at great depths. Replacement and maintenance can be costly.

Technology Review