WorldWide Drilling Resource

Directional Drilling for Geothermal Power? Adapted from Information by the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy Directional drilling has gained a lot of popularity in the drilling world. It makes utility replacement easier, and is being used in the gas and oil industry for hydraulic fracturing. So, what about the geothermal drilling industry? When it comes to geothermal energy, there is an immeasurable amount of energy lying beneath our feet. Not only is this energy renewable, it is also nearly free of emissions. One of the problems with developing geothermal resources is the immense heat encoun- tered in the deep subsurface which makes it a difficult environment to work in. Engineers seeking to tap geo- thermal resources often encounter extremely high temperatures, extreme pressures, and crystalline rock formations which can make things complicated. This is where highly advanced drilling technologies and techniques, push- ing the envelope of what can be achieved in conventional drilling operations, come in. Baker Hughes Incorporated, with investment from the U.S. Department of Energy’s Geothermal Technologies Office (GTO), recently developed and successfully demon- strated an advanced drilling system designed for these critical conditions. This technol- ogy can drill directionally at extremely high temperatures (over 570ºF / 300°C). The system uses a high-temperature lubricant in the drilling fluid, a full metal drill bit to break the formation, and a full metal drilling motor known as a metal-to-metal motor. Recently, Baker Hughes successfully directionally drilled with this innovative system in a deep geothermal well. In fact, the metal-to-metal motor operated for a continu- ous 270 hours - the longest time a system like it has ever operated. Due to its reliability in extreme subsurface conditions, the successful operation of this drilling system could have major impacts. Not only does this technology advance the state of geothermal technolo- gies and open more geothermal resource areas for development, other subsurface sectors such as fossil and nuclear energy are ready to embrace the recent develop- ment. These sectors can leverage the work funded by the geothermal energy sector. The energy resources this break- through could make available to devel- opers will be immense and difficult to calculate, and the potential economic im- pacts are currently undefined. Expanding EGS (Enhanced Geothermal Systems) alone could eventually lead to more than 100 gigawatts of economically viable electric generating capacity in the conti- nental United States - enough to power more than 100 million homes. As the geothermal, oil and gas, and nuclear industries adopt this cutting- edge technology throughout the nation’s energy portfolio, Baker Hughes and GTO’s research in drilling technology could help the nation on a path toward improved energy security and a stronger economy. 29 WorldWide Drilling Resource ® JUNE 2017