Video: University explores geothermal heating option
S. Himmelstein | July 29, 2022In alignment with the goal to achieve carbon neutrality by 2035, Cornell University is exploring the potential of onsite geothermal resources to provide campus heating services. Drilling for the Cornell University Borehole Observatory (CUBO) is now underway and will be the site of tests to determine the temperature, permeability and other characteristics of the rock up to 10,000 ft below the surface.
To date, engineers and geologists have drilled to a total depth of 6,826 ft or 68% of the target depth of 10,000 ft. This corresponds to the 12.25 inch well section planned to a depth of 7,900 ft. After casing and cementing this section, drilling will proceed to the target section for CUBO, and a fiber optic cable will be installed to allow temperature measurements across those deepest rock layers and long-term monitoring.
The Cornell University Borehole Observatory. Source: Jason Koski/Cornell University
The next phase entails drilling a separate pair of wells to act as an injector and producer. Hot geothermal water would be pumped from the production well and sent through a heat exchanger, and then reinjected into the second well to circulate through the network of naturally hot underground pores and crevices to be reheated and complete the cycle. At the heat exchanger, the heat would be transferred to a district heating system that runs through campus and connects to individual buildings.
I'm curious how much energy it takes to drill a 12.25" hole 10,000 ft into the rock and how long it takes to recoup that energy.
In reply to #1
Depends a lot on the strata how much energy is used but when I worked on oil rigs the generating capacity used was up to 2MW per hour of drilling time. Power was supplied by 3 Cat engines with 2 on line at a time each connected to 1MW generator and feeding SCR control. Where we were drilling on a good run it took 2 weeks from spudding in to 3000m depth but there were stops for bitt changes and casing runs as well as time out to let cement cure.
Have no idea of the energy used, it really didn't matter, but a 75% run time at full noise would yield 1296 MWHr.