HYDRAULICALLY FRACTURED HORIZONTAL WELLS AND OTHER OILFIELD TECHNOLOGIES ARE ABOUT TO REVOLUTIONIZE THE PRODUCTION OF ELECTRICITY FROM GEOTHERMAL RESOURCES

Hydraulically fractured horizontal wells are poised to revolutionize the production of electricity from geothermal resources much as they did for the production of oil and natural gas from unconventional reservoirs. This should not be surprising since the key to unlocking both resources involves creating an extremely large amount of fracture surface area given that heat “flows” at a very slow rate via conduction through most lithologies and hydrocarbons move at a similar pace through nanodarcy permeability reservoirs. That geothermal resources have been a largely overlooked solution for providing the affordable, clean, base-load power needed for reducing greenhouse gas emissions is primarily due to two reasons:

1. The fact that hydrothermal systems (i.e., systems capable of flowing hot fluids to the surface without the need for hydraulic fracturing) are exceeding rare – so rare that exploring for them has resulted in exploration expenses far exceeding the value of the resources one could reasonably expect to find, and
2. Previous attempts to create Enhanced Geothermal Systems (EGS) almost exclusively relied on the use of vertical wells, which is a well geometry from which it is almost impossible to create sufficient fracture surface area via hydraulic fracturing, leading to either: i) rapid thermal breakthrough between injectors and producers, or ii) the inability to connect injectors with producers, resulting in numerous development dry holes and marginal producers.

These two EGS failure mechanisms can however be relatively easily addressed by using hydraulically fractured horizontal wells since it is possible to create orders of magnitude more fracture surface area from horizontal wells than can be created from vertical wells, thereby making it much easier to connect EGS injectors with producers, avoid thermal breakthrough, and “harvest” resources much more quickly (i.e., heat for EGS). This is exciting news for the geoscience community given that geothermal resources are not nearly as well characterized as hydrocarbon resources, and therefore, will create an enormous need for geologic and geophysical studies and technological advancements. It is also exciting news for the planet as a whole given the world needs enormous volumes of clean energy to successfully transition to a low-carbon future and heat within our planet's crust can provide an almost inexhaustible source.