[FISH] Tianze Liu (WHOI)

“Seismic and borehole-acoustic observations of free-gas migration and tensile fracture growth during low-temperature peridotite alteration”

The dual capacity of peridotite formations to produce hydrogen and absorb CO2 through low-temperature alteration is attracting increasing interest from the energy industry. However, key questions regarding the alteration processes remain, including: (1) How does the hydrogen produced by serpentinization migrate in the formation, and (2) Can the alteration-induced volume expansions fracture the rock, promoting further alteration by creating new reaction surfaces? In this talk, I will synthesize observations from a unique seismic and borehole-acoustic experiment at the Oman Drilling Project Multi-Borehole Observatory, which detected a variety of signals associated with active peridotite alteration. We find that free gas migrates through the subsurface fracture network in a highly dynamic manner and that active alteration likely maintains near-critical stress at the tensile fracture tips in the borehole, such that small pore-pressure perturbations can trigger fracture growth. Our results indicate that: (1) Free gas may be more prevalent in peridotite formations than previously estimated, (2) Seismological techniques can effectively monitor free-gas migration in peridotite formations, and (3) Active alteration may facilitate fracture growth during stimulated geological hydrogen production and carbon mineralization.

Friday Informal Seminar Hour —

Postdoc-run seminar series within the Earth Resources Laboratory (ERL). Features talks by ERL members as well as special guests from academia and industry on earth science and energy transition topics including geothermal energy, carbon sequestration, geologic hydrogen, and critical minerals / in situ mining.

Contact: fish_seminar_organizers@mit.edu