FastCap Systems wants to change how drillers power instruments in high-temperature wells where lithium batteries are currently the power supply of choice.
Their innovation: a new generation of capacitor. FastCap says it is selling a version of the device that uses carbon nanotubes to greatly increase its capacity to store and deliver power. Since it debuted at last year’s Offshore Technology Conference, FastCap’s ultracapacitor—created using technology developed at the Massachusetts Institute of Technology—has attracted interest from several companies in exploration and production (E&P), said Jamie Beard, director of operations for FastCap.
“We find customers really value our core technology. It is something that does not exist: a rechargeable, high-power, high-temperature power source,” Beard said. What they plan to do with it varies because “it is just a different beast.”
It is also rechargeable, which isn’t the case with the sort of lithium batteries currently used on high-temperature wells, and it can perform at temperatures exceeding 150oC. The company’s goal is to prove it can be used at 250oC. And according to FastCap’s website, the ultracapacitor can store far more power than other capacitors—3 times more than the highest-capacity capacitor—and deliver it 10 times faster than any battery.
While Beard said the device could someday be used to replace lithium batteries, early interest comes from those who are looking for ways to do what capacitors are most often asked to do: provide bursts of power stored up from a steady current from lithium batteries.
“It is like any capacitor, but on steroids,” said Mark Kaulback, chief operating officer of Payzone Directional Drilling. The company wants to use it to increase the power available downhole while it is drilling horizontal wells, allowing it to communicate faster to downhole tools using electromagnetic telemetry (EM). In some of the busiest formations, such as the Bakken and the Permian Basin, it has to rely on mud-pulse telemetry. EM offers more bandwidth and is not interrupted when drilling stops and the mud pumps are shut down, so it also saves time and money.
The goal is to use the extra power to maintain EM connections in reservoirs where it currently isn’t available, since EM does not have the downhole power to generate a signal capable of overcoming the resistivity of the rock and the distances a signal must travel, Kaulback said. Payzone is planning to test a combination of the FastCap ultracapacitor and lithium-thionyl chloride batteries, which are now the standard for directional drilling.
“This system could be a game-changing technology to provide power for EM telemetry drilling” if the combination delivers as planned, Kaulback said. Payzone is now doing lab tests and hopes to do a field test later in the year.
Some companies are also looking to see if the ultracapacitor can be used in tandem with downhole electric generators, Beard said. The capacitor would step in and provide power when the generator stops because the mud pumps are not working.
Beard said most E&P companies are more interested in the ultracapacitor’s ability to deliver large amounts of power, as well as its power control system that limits the number of rapid discharges, which can quickly kill a battery.
The allure of such a power option isn’t new. There have been many promising power innovations over the years that have all looked like the future but which have not been heard from since. Some of those projects are still around—battery development is a long-term proposition—but others failed to catch on in the E&P market, which presents difficult technical challenges.
“We meet with a lot of disbelief,” Beard said. “A lot of big companies also tried to make high-temperature batteries. A lot of companies with really gigantic resources and a lot of PhDs and resources tried this and have not gotten it to work.”
FastCap’s technology was developed with support from the US Department of Energy, which is seeking a power source for drilling in geothermal wells where temperatures far exceed what available batteries can tolerate. The FastCap capacitor has been tested at temperatures of up to 150oC in the Sandia National Laboratories. Beard said that tests at 215oC were scheduled in February, and that the plan is to ultimately certify it to operate at 250oC.
One of the company’s technical advisors is Richard Sears, a consulting professor in the Department of Energy Resources Engineering at Stanford University, who sees it as a useful complement to batteries that could allow safer operations.
“What a great application for an ultracapacitor,” Sears said. “It can store power from lithium or alkaline batteries and take care of high power demand that comes in burst during transmissions.” He pointed to safety issues associated with lithium batteries, including their ability to catch fire or explode when there is a runaway thermal reaction, which has occurred in cars, laptops, passenger jets, and oil wells using lithium batteries. The FastCap website shows its ultracapacitors sawed in half or punctured and still working.
“If you actually eliminate lithium batteries from the oil and gas business, you are really doing a good thing,” said Sears, who served as an advisor for the national commission that investigated the Macondo blowout after retiring from Shell Oil deepwater exploration.
It is too soon to know what, if any, niche will be there for FastCap’s capacitors. But Beard says there is no shortage of interest.
“Every time we talk to someone new, we come up with a different type of problem,” Beard said. “They are not shy about telling us their problems. When you talk to someone about batteries, it turns into a therapy session for their battery-related drilling issues.”
Stephen Rassenfoss is the Emerging Technology Senior Editor for the Journal of Petroleum Technology.