Phase 1 of
Quaise Energy’s Project Obsidian is underway in Oregon as construction
commenced in April. The goal of the project is to tap into hot rock greater
than 300 degrees C (572 degrees F). The project is hoped to be operational and
producing power in 2030. The first power plant is slated to make 50MW of
low-emissions baseload power. Phase 2 is expected to target 250MW,
and the final goal for the area is 1GW of power production capacity.
Quaise has been working on
its subsurface and heat modeling. According to Daniel W. Dichter, a senior
mechanical engineer at Quaise:
“This analysis validates our long-held hypothesis that
higher subsurface temperatures entail substantial improvements in power
production. It shows us that we can get to a capacity of 50 megawatts of power
with this system.”
“If these first wells work the way we think they will,
they will be on par with exceptionally productive oil and gas wells in terms of
equivalent power output.”
Phase 1 plans are detailed
below:
“The first phase of Project Obsidian will consist of two
separate geothermal well systems. One will target rock at temperatures reaching
as high as 365 degrees Celsius (689 degrees F) with an average temperature of
315 degrees C. The other will target rock at temperatures as high as 415
degrees (779 degrees F) with an average temperature of 365 degrees C.”
“Why build two systems targeting different temperatures?
The one targeting an average of 315 degrees C, says Dichter, “is on the cusp of
what is achievable today, so it’s lower technical risk. With what we learn from
that system, we’ll go to the hotter one, which is riskier.”
Quaise has classified its
project criteria into three types: Tier I, which accesses shallow superhot
rock, which is only available in certain places. Project Obsidian is being
developed in a Tier I location; Tier II locations will drill to rocks at
intermediary geothermal gradients, which make up nearly 40% of the world; Tier
III involves drilling as much as 19 kilometers down (about 12 miles). That will
be the real test for millimeter wave drilling, since it will exceed the deepest
drilled wells globally. Quaise’s process involves drilling down first with the
conventional rotary drilling technology utilized in the oil & gas industry,
then drilling the deeper basement rocks, typically granite and other igneous
rock, with millimeter wave technology. Theoretically, once Tier I and Tier II
sites are developed, learning from that can be applied to Tier III sites.
Below are some of the details
of the first drilling to be done at the site:
“Each of the two well systems, in turn, comprises three
wells. Water will be pumped down one of these to the hot rock. The two wells on
either side will capture the hot water that results from flowing through the
hot rock. Contributing to the project’s small footprint: the pipes conveying
water to and from the SHR {superhot rock} formation have a maximum inner
diameter of only about ten inches.”
“The first phase of Project Obsidian will also have a
seventh, or confirmation, well. This one—the first to be drilled— will give the
Quaise team key information on variables including the geomechanical, or
physical, properties of the superhot rock. These data will dictate, for
example, how the team fractures rock at depth to create pathways for water to
flow.”
“The confirmation well is expected to be in operation
later this year.”
Below, what may be learned by Phase I to improve the project is given.
History and Potential of Millimeter Wave Drilling and
Borehole Vitrification
An article for the American
Ceramic Society explores the science and technology of millimeter drilling.
Higher temperatures and pressures in deeper rocks can cause conventional
tungsten carbide or diamond-tipped drill bits to fail. The mechanical teeth are
pulverized, and the bearings wear down to nothing in a matter of hours. Hard
rock drilling in hard granitic rocks can drop to less than a meter per hour and
lead to multiple hours-long tripping out and in of drill pipe to change the
bit. The article explains:
“Millimeter wave (MMW) drilling is a paradigm-shifting
directed-energy approach to achieving universal superhot rock access by melting
and vaporizing rock rather than grinding it. It is more efficient than
traditional drilling because there are no cutting heads to wear out. Rather
than fighting the superhard bedrock, it simply melts it out of the way…”
“MMW drilling leverages a well-established nuclear
fusion technology: the gyrotron. A gyrotron is a high-powered vacuum tube that
emits millimeter-wave electromagnetic radiation. These waves are traditionally
used to heat plasma in fusion reactors, but ceramic engineers may also use them
to sinter advanced ceramics. In the case of MMW drilling, the gyrotron is used
to melt and vaporize the hard bedrock.”
The long wavelengths of the
energy beam generated by the gyrotron make it much more efficient for heating
and melting rock, up to five times more efficient than shorter wavelengths.
“High-pressure gas streams (such as nitrogen or argon)
are continuously injected downhole to flash-cool the hot rock vapors into fine
nanoparticles, flushing them cleanly up and out of the wellbore.”
“The intense high-frequency thermal energy fundamentally
alters the borehole walls. As the primary beam vaporizes the central core of
the hole, the peripheral heat partially melts the surrounding rock walls. As
this molten layer cools, it transforms into a permanent glass-like liner.
Vitrification has the following intrinsic advantages:”
In 2009, scientists at MIT
validated millimeter wave drilling. The MIT scientists and some geothermal
geologists and engineers from AltaRock Energy founded Quaise Energy in 2018.
They got an ARPA-E grant in 2019 and secured $6 million in seed funding in
2020.
“Quaise’s long-term goal is to deploy MMW drilling rigs
at soon-to-be-decommissioned coal and natural gas power plants. By drilling
deep, localized superhot rock loops at these facilities, they can swap out the
old fossil-fuel boilers and feed clean geothermal energy directly into the
plant’s turbines and export it through the existing electrical grid connection.
This setup preserves local energy jobs and saves trillions in capital
expenditures.”
There are still some
engineering challenges to be worked out as the technology is further validated.
They are listed below:
As the abstract from a paper
about Project Obsidian, published in the Proceedings of the 51st Workshop
on Geothermal Reservoir Engineering at Stanford University notes, the
project is an enhanced geothermal project that requires hydraulically
fracturing the impermeable rock after drilling and adding water to the newly
created reservoir. The abstract discusses the well and power plant
configurations.
According to the paper:
“The wells are planned to be drilled vertically until
reaching approximately 2 km TVD, after which they back-track slightly, then
follow a straight path inclined at 45°. This inclination provides horizontality
in the feedzone such that the wells can be connected by a series of fractures,
which are expected to propagate approximately in the vertical direction. The
chosen inclination angle may be modified within the approximate range of 45-80°
based on confirmation well results, challenges associated with high-temperature
directional drilling, and stimulation modeling. Regardless of the inclination
angle, the trajectory is planned to provide a feedzone measuring at least 1 km
long as projected onto the ground plane. The producer wells have a 7” outer
diameter casing below about 2.5 km TVD, and a 9 5/8” outer diameter casing
above; the injector wells have similar trajectories with a 7” outer diameter
casing throughout.”
Below is a graph of the modeled energetic
power in MW vs. Enthalpy in kJ/kg.
References:
Quaise
Energy on track to build world’s first power plant using superhot geothermal
energy. Elizabeth A. Thomson. April 22, 2026. Quaise Energy. Quaise
Energy on track to build world’s first power… | Quaise Energy
Concept
of a High-Temperature EGS Plant in Central Oregon. Daniel W. Dichter, Trenton
T. Cladouhos, Quinlan Byrne, Victor J. Rustom, and Greg Szutiak. PROCEEDINGS,
51st Workshop on Geothermal Reservoir
Engineering. Stanford University, Stanford, California, February 9-11, 2026. SGP-TR-230.
Concept
of a High-Temperature EGS Plant in Central Oregon
Millimeter-wave
drilling: Extracting geothermal energy through vitrified boreholes. Ceramic Tech
Today. The American Ceramic Society. May 28, 2026. Millimeter-wave
drilling: Extracting geothermal energy through vitrified boreholes - The
American Ceramic Society
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