The Advanced Geothermal Systems panel at the University of Texas Energy Forum reviewed both current and promising new advanced geothermal systems, much of which receives DOE support. "I am in full support of R&D that provides electrical power at lower risks and lower costs," said Douglas Hollet, director of geothermal technologies in Washington, D.C., who attended the forum.
Eric Hass, program manager for hydrothermal resources at the DOE, moderated the panel. The Panel members were: Douglas Blankenship, manager of the geothermal research department at Sandia National Laboratories, who gave an overview of current status of Enhanced Geothermal Systems (EGS). He outlined both its tremendous long-term potential due to the vastness of the hot dry rock resource and its challenges in creating artificial reservoirs. Brian Anderson, associate professor at West Virginia University, added that it is difficult to attain closed circulation between injection wells and production wells, which results in the loss of working fluid and can lead to beneficial sequestration of the CO2 into the earth when using CO2 as the working fluid. Both Doug and Brian concluded that EGS technology will not be commercially viable for several years, but its long-term potential is very promising.
Panelist Andres Ruzo, a Geophysics PhD Candidate at Southern Methodist University (SMU), which has been at the forefront of advancement of oil and gas/geothermal utilization, described his work to identify and characterize wells that have potential for oil and gas and geothermal co-production that was funded by the DOE and partially funded by a grant from Google. Find SMU geothermal research here.
I served as the final panelist and presented an overview of saturated gas geothermal, which extracts natural gas from methane-saturated brine while generating base-load geothermal power or uses the mechanical force produced by geopressure or a geothermal power cycle to produce LNG. It is an emerging long-life, advanced geothermal system that has the potential to bring together the oil and gas industry and the geothermal industry for the first time because both saturated gas extraction and geothermal power generation operate for many years. By using geothermal- or geopressure-generated mechanical power to produce LNG instead of electricity, the technology has the potential to provide LNG as a fuel to power America’s trucks and cars for thousands of years into the future.
Oil and gas production often has an eighty-five percent decline curve in the first year. Most operators do not wish to continue to pay for oil and gas leases and be responsible for plugging liabilities for long periods of time. By contrast, saturated gas geothermal provides long-term operation of about twenty years with almost no drop in production – it is capable of supplying clean burning natural gas, base-load geothermal generated electrical power, fresh water produced from brine and low cost LNG.
The proven reserves of natural gas saturated into brine in just the Southern parts of Texas and Louisiana are thousands of times greater than all of the other sources of natural gas known worldwide, including shale gas. And, because the resource is so vast it can produce natural gas and base-load geothermal power for thousands of years into the future.
Director Hollet stressed that the DOE is diligently working to provide a comprehensive well data base to support both geothermal and the oil and gas industry in regard to having the information needed in order to support the geothermal and the oil and gas/geothermal co-production industries. He further added that they have had several recent success stories regarding the work funded by DOE. Panel moderator Eric Hass echoed Director Hollet’s comments and presented further details regarding the DOE’s recent achievements, which includes three successful EGS projects, of which I am sure we will be hearing more about in the near future.
Lead image: Geothermal power station via Shutterstock