Recently demonstrated enhanced geothermal (EGS) approaches utilize the tools of unconventional oil and gas for geothermal applications; they present a significant scalable opportunity for low-carbon energy production. Simultaneously, a variety of interesting scientific challenges have been exposed during EGS pilot projects over the last decade, particularly that of understanding the induced fracture network geometry and interactions between such networks and existing basement structural features. We present results from a series of studies utilizing novel high-temperature fiber-optic sensing tools (DAS) and imaging algorithms to unravel such interactions at the Utah FORGE and Cape Station sites. We highlight the use of DAS microseismic reflection imaging, DAS microseismic event characterization, and low-frequency DAS to better understand these processes at the reservoir scale.

Bio: Dr. Jonathan Ajo-Franklin is the Carey Croneis professor of geophysics at Rice University and chair of the Department of Earth, Environmental, and Planetary Sciences (EEPS). He is also a visiting faculty scientist in the Energy Geosciences Division at Lawrence Berkeley National Laboratory (LBNL). Jonathan is an applied geophysicist working on problems in the environmental and energy domains including geothermal energy production, geological carbon storage, and near-surface hydrogeophysics. His group specializes in new acquisition and processing strategies for timelapse seismology including distributed acoustic sensing (DAS), permanent seismic source development, and high-resolution ambient noise approaches. He is also interested in the microscale physics and chemistry of geomaterials relevant to interpreting geophysical datasets, particularly the properties of fractures and mechanical alterations during reactive flow. He led the recently completed Imperial Valley Dark Fiber Project (DOE GTO) which explored approaches for geothermal exploration using DAS deployed on telecom fiber and was the PI of FOGMORE@Utah FORGE, an R&D project exploring integrated fiber-optic sensing for geothermal reservoir monitoring. Jonathan received his BA in Computer Science and History at Rice University (1998), followed by an MS (2003) and PhD (2005) in Geophysics at Stanford University. After his postdoctoral studies at MIT’s Earth Resources Laboratory (2005-2007), he spent 12 years on the staff at LBNL before joining the faculty at Rice EEPS in 2019.