When we think directional drilling, we think oil and gas. But a recent article in Think GeoEnergy tells about an advanced drilling system used by Baker Hughes that can withstand high temperatures in drilling for geothermal resources. The project was funded by the U.S. Department of Energy and its Geothermal Technology Office.
Alexander Richter for Think Geoenergy reports that Baker Hughes, with investment from the Geothermal Technologies office (GTO) have successfully tested an advanced geothermal drilling system that can drill in extreme temperatures, around 300°C. Baker Hughes’ new “metal-to-metal motor” tested the system in a deep geothermal well for a continuous 270 hours.
Richter also mentions that the new technology could also affect more than just the growing geothermal energy industry:
Not only does this technology advance the state of geothermal technologies and open more geothermal resource areas for development, other subsurface sectors such as fossil and nuclear energy are ready to embrace this recent development.
Baker Hughes has been working in the geothermal energy industry in Germany, Iceland and in the United States. In 2007, the Chena Hot Springs resort northeast of Fairbanks, Alaska became the state’s first viable geothermal project. In Houston, Baker Hughes’ Technology center works to develop Enhanced Geothermal Systems (EGS), engineered reservoirs that produce energy otherwise uneconomical because of a lack of water and/or permeability, according to the company’s website.
Compared to oil and gas reservoirs, geothermal formations are very hot, hard, abrasive and often contain corrosive fluids. While these barriers make geothermal wells expensive and often difficult to drill, once a well is drilled the long-term benefits often outweigh those barriers. Oilprice.com notes that geothermal electricity is…
…about as close to a perfect source of renewable energy as one can get. It’s (almost) carbon-free, doesn’t emit large quantities of noxious gases or generate radioactive waste, doesn’t require the clear-cutting of virgin forests, doesn’t take up lots of room, doesn’t blight the skyline (or at least not all that much), doesn’t decapitate or incinerate birds, is replenished by the natural heat of the Earth, delivers baseload power at capacity factors usually around 90% and can even if necessary be cycled to follow load. It’s also one of the lowest-cost generation sources presently available. No other renewable energy source can match this impressive list of virtues or even come close to it.
However, geothermal fields are not as numerous as oil and gas fields, and the difficulty of geothermal drilling and transporting the energy is difficult. The transport is dangerous, and many of the plates where geothermal energy exist are mountainous terrains that make both drilling and transport very difficult. (Imagine drilling in the middle of the Andes Mountains, for example.)
Despite the drawbacks, companies like Baker Hughes continue to develop geothermal drilling techniques. The discussion about climate change makes geothermal energy a more attractive energy source that it was previously, and the company expects the demand for geothermal energy to triple in the next 25 years due to its low cost and environmental benefits. Richter states:
Expanding Enhanced Geothermal Systems alone could eventually lead to more than 100 gigawatts of economically viable electric generating capacity in the continental United States—enough to power more than 100 million homes.