Abandoned and orphaned oil and gas wells pose significant public health problems and threats to the environment. In general, abandoned wells are unproductive wells with an identifiable owner, whereas orphaned wells are unproductive wells without an identifiable owner. An idle oil well refers to a well that is temporarily not producing oil or gas but has the potential to be brought back into production. It might be shut down for maintenance, repairs, or due to economic factors such as fluctuating oil prices. There is a growing narrative that the existing infrastructure of idle wells could be repurposed for use in the energy transition having social and environmental benefits.

Geo2Watts has developed a patent pending technology that can repurpose idle oil wells for LDES to generate clean dispatchable electricity while concurrently plugging them trademarked as the Borehole Battery™. Here is how it works: Once an idle oil well is permanently plugged meeting mandated regulatory protocols, a closed-loop heat exchanger is installed with a proprietary combination of thermal conducting and insulating materials, effectively converted the well into a Thermal Energy Storage (TES) system. Solar thermal collectors are used as the source of renewable heat combined with a Reversible High Temperature Heat Pump (RHTHP) for heating pressurized water up to 200°C, which is then circulated throughout the TES. During electricity production, pressurized water flows through the heat exchanger within the TES and then transferred to the RHTHP for producing clean dispatchable electricity. The optimized design of the TES and its heat exchanger surrounded by proprietary thermal materials, combined with the RHTHP and solar collector field, form the critical components of this novel system.

California has over 37,000 idle oil wells and the Permian Basin has approximately 100,000 idle oil wells. Repurposing these wells could provide a valuable source of clean, dispatchable electricity to meet rising power demands and offset the intermittency of renewables, rather than letting them contribute to pollution. Repurposing idle oil wells provides a strategic alternative to plugging and offers owners a future source of revenue from underperforming wells that are nearing the end of their life cycle.

Implementing the Borehole Battery™ on a large scale would significantly reduce the number of idle wells. This approach involves sealing producing zones to prevent methane leakage and repurposing existing infrastructure. Additionally, it would enhance energy storage capacity by providing on-demand, zero-emission, dispatchable electricity during peak hours.