Sandia National Laboratories
Exceptional service in the national interest
Geothermal energy is an abundant energy resource that comes from extracting natural heat of molten rock deep beneath the Earth’s surface. It is a green energy source that is thousands of times greater than the world’s oil reserves. Geothermal energy can be used to generate electricity, heat buildings, and drive industrial processes while emitting virtually no environmentally harmful gases.
Sandia’s Geothermal Research program has been at the forefront of innovation and R&D for the past four decades. It applies electrical and mechanical engineering, geothermal energy system knowledge, and laboratory and field testing, to develop downhole tools to access deep, hot, and chemically harsh subsurface environments for geothermal, oil and gas, environmental restoration, mine rescue, energy storage, and national security missions.
Because a large portion of the cost and risk of generating electricity from geothermal sources is associated with drilling and completing exploration, production, and injection wells, Sandia’s primary focus has been on the development of improved drilling and completion technologies such as diagnostics while drilling, high-temperature electronics, advanced drill bit technologies, and wellbore integrity technologies to reduce and mitigate problems associated with loss of circulation.
Sandia’s work in subsurface access, monitoring, and modification of the subsurface is aimed at the development of enabling technologies and reducing the cost and risk associated with drilling in harsh, subterranean environments. Historically, research has focused on significantly expanding the nation’s utilization of geothermal energy. Geothermal-related research studies practical solutions to challenges associated with tapping the most intense sources of heat, found well below the earth’s surface in severe environments.
A large portion of the cost and risk of generating electricity from geothermal sources is associated with drilling and completion of wells. Because of this, Sandia has primarily focused on developing improved drilling and completion technologies such as diagnostics while drilling, high-temperature electronics, advanced drill bit technologies, and wellbore integrity technologies to reduce and mitigate problems associated with loss of circulation.
Sandia also actively works on advanced drilling concepts to provide economical access to deeper and hotter resources in the future. Most of these research projects are conducted in cooperation with geothermal operators and companies within the well service industry. On a cost-per-foot basis, geothermal drilling is among the most expensive type of drilling performed; Sandia’s work in this area has created natural synergies that benefit other industries and agencies that require drilled access to the underground.
Modeling plays an important role in understanding and predicting geothermal system performance and sustainability. Geothermal energy development is unique in that there is direct feedback between system design and operations and system performance. Modeling aids in understanding sub-surface processes that cannot be directly observed while being able to place those processes into the larger context of economic and thermal performance.
Using advanced numerical methods and massively parallel high-performance computing, Sandia is able to simulate processes important to geothermal development and energy production across a wide-range of scales from thermal, hydrological, mechanical, and chemical (THMC) processes at pore and fracture scales to project-scale analyses of physical and economic performance. This provides developers and operators insights that help minimize economic risk while maximizing system performance and sustainability.
Under the leadership of Lawrence Berkeley and Sandia National Laboratories, researchers are working to validate and verify models of enhanced geothermal reservoir behavior within the Sanford Underground Research Facility (SURF) in South Dakota in advance of full-scale site research at the FORGE laboratory in Milford, Utah. Early results are promising as the team, titled EGS Collab, continues rigorous onsite monitoring and testing. This research is sponsored by the U.S. Department of Energy’s Geothermal Technologies Office.
In partnership with the New Mexico Institute of Mining and Technology, Sandia operates a drilling and stimulation test site for field testing. Research at the site includes seismic imaging, testing, and analysis.
More than 50 percent of a geothermal power plant’s capital cost can come from drilling and completing the well. Sandia investigates new drilling processes and tools that could make geothermal energy a practical and affordable energy source.
Reliable drilling technology is also vital to ensure access to our diminishing oil and gas reserves. These remaining hydrocarbons are often found in deep reservoirs with ever increasing downhole temperatures and pressures. Many of the challenges in oil and gas drilling are similar to those encountered in geothermal well construction.
Sandia also supports a variety of non-energy related governmental programs that require drilling research to support other national security objectives. Through a strong application-oriented R&D approach, Sandia is uniquely qualified to apply drilling technology to these applications and develop new technologies to address the challenging problems necessary to ensure our national security.
Geothermal resources are typically associated with igneous and metamorphic rocks, which are harder than the sedimentary rocks through which most oil and gas wells are drilled. Sandia’s Hard Rock Drilling Facility (HRDF) consists of a structural steel frame that houses a hydraulic top-drive motor and hydraulic cylinders used to apply weight-on-bit (WOB). The facility is configured to house a test specimen for drilling. The rock sample can be positioned at various locations beneath the drill head allowing multiple holes to be drilled for each rock sample.
Sandia’s High-Temperature Electronics facility provides component fabrication facilities and test equipment for the development of high-temperature electronics, electromechanical and optical-fiber based equipment.
Sandia’s High Operating Temperature (HOT) Facility houses a 20-foot-tall drill rig, heating chamber, and process gas heater. Researchers can simulate conditions deep underground and the elevated temperatures affecting the hammer and can drill into different types of rock, like the granite commonly found in geothermal-rich areas. In addition to testing drilling tools at temperature, the facility is also capable of conducting research in drilling automation and control.