[FISH] Peter Malin (Duke University)

This week’s talk is being held virtually.

“Fluid Flow in the Geocritical Crust – Observations and Theory”

The crust is in a state of critical stress caused by a variety of forces – tectonic, flexure, tides, fluids, earthquakes, etc. This state can be quantitatively described by ideas based in critical state physics. In the brittle crust the result of this state is that stress changes of less than bars can cause minute displacements on pre-existing, fluid-filled fractures, resulting in complex seismic emissions. Field observations and critical state numerical models of these emissions reveal how they can be used to map permeable networks for practical applications. This includes drilling targets, stimulation monitoring, and reservoir management. We describe the basic ideas of the geocritical state, how it can be used to understand subsurface fluid flow, and to fill in the permeability field of the crust. We also present the results of passive seismic monitoring of emissions at the Newberry Geothermal Field in Oregon. The structure and distribution of the observed emissions is consistent with regional and local tectonics, magnetotelluric resistivity profiling, and near-well drilling observations. We interpret these results in terms of near-well fluid filled fracture networks.

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 the energy industry on topics including seismology, geothermal energy, carbon sequestration, machine learning for geophysics, multiphase flow, subsurface imaging, and uncertainty quantification.

Contact: fish_seminar_organizers@mit.edu