Research Triangle Energy Consortium

Few will dispute the fact that the US was a net importer of natural gas in 2007. Cheniere Energy was gearing up to import liquefied natural gas (LNG) and deliver it to the country. Then natural gas from shale deposits became economic and scalable. How Cheniere reinvented their business model by pivoting to convert their re-gas terminals to become LNG producers is a story for another time. As is the tale of shale gas singlehandedly lifting the US out of recession. Low-cost energy is a tide that lifts all boats of economic prosperity, and this one sure did.

The story for today is that the technologies that enabled shale gas production are showing up as key enablers for geothermal energy, the leading carbon- free energy source which can operate 24/7/365, unlike solar and wind, which are intermittent, with capacity factors (roughly defined as the portion of time spent delivering electricity) of up to 25% and 40%, respectively. The short duration intermittency (frequently defined as under 10 hours) is covered by batteries. But for longer periods, the most promising gap fillers are geothermal energy, small modular (nuclear) reactors and innovative storage means. Of these, the furthest along are geothermal, as represented by advanced geothermal systems (AGS), some battery systems, and hydrogen from electrolysis of water using power when not needed by the grid.

The most commercially advanced AGS variant is that of Fervo Energy. It employs two parallel horizontal wells intended to be in fluid communication.  Hydraulic pressure is used to create and propagate fractures from the injector well towards the induced fractures at the producer well. Fluid is pumped into the injector well and flows through the fracture network into the producer well. Along the way, it heats up while traversing hot rock. This hot fluid is used to generate electricity. It may also be used for district or industrial heating. The heat in the rock is replenished by heat transfer from near the center of the earth, where it is created by the decay of radioactive substances. The center of the earth is at temperatures close to that of the sun.

The two key enabling technologies for accomplishing the process described above are those of horizontal drilling (and drilling a pair reasonably parallel to each other) and hydraulic fracturing, known in industrial parlance as “frac’ing”.  Clever modeling (from a co-founder’s PhD thesis at Stanford) dictates many operational parameters such as optimal well separation, but the guts of the operation is that employed in shale oil and gas production. With one difference. The temperatures are greater than in most conventional shale operations. This affects the drilling portion more than the fracturing one.  Temperatures will be greater than 180 C in AGS operations, and in excess of 350 C in the so-called closed loop systems (which have no fracturing involved, except for one minor variant).  Even in AGS systems, higher temperatures are preferred, and Fervo recently demonstrated operations at 250 C. While this stresses industry capability, it still falls firmly in oil and gas competency and the geothermal industry can rely upon this rather than attempt to invent in that space.

The frac’ing dividend mentioned in the title of this piece refers to advances in frac’ing operations which accrue directly to the benefit of AGS operations.  A key one is the ability to use “slick water”, which is fracturing fluid with little to no chemicals.  Opponents of shale gas operations have often cited the possibility of surface release of these chemicals as a concern.  Similarly, accidental surface release of hydrocarbons in fracturing fluid has been a concern but is irrelevant here because of the complete absence of hydrocarbons in the rock being drilled. AGS operations do have the possibility of induced seismicity. This is where the pressure wave from the hydraulic pressure potentially energizes an active fault, if present in proximity, and the resulting slip (movement between rock segments) causes a sound wave in the seismic range. However, the risk is small, especially if the activity is in a naturally fractured zone, in which fractures can be propagated at lower induced pressures than in unfractured rock. In any event, competent operators such as Fervo are placing observation wells and to date induced seismicity has not been a concern. The sound heard is that of (relative) silence*.

Finally, the shale oil and gas industry devised economies of scale by placing multiple wells on each “pad”.  These techniques, including elements such as the rigs moving swiftly on rails, are directly applicable to AGS systems using frac’ing. So, any reported economics of single well pairs could, in my opinion, be improved by up to 40% when tens of well pairs are executed on a single pad.

This is the big frac’ing dividend.

Vikram Rao

June 29, 2025

*And no one dared disturb the sound of silence, from The Sound of Silence, performed by Simon and Garfunkel, 1965, written by Paul Simon.

Tagged: climate-change, energy, renewable-energy