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Changes in permeability caused by transient stresses: Field observations, experiments, and mechanisms
Author(s) -
Manga Michael,
Beresnev Igor,
Brodsky Emily E.,
Elkhoury Jean E.,
Elsworth Derek,
Ingebritsen S. E.,
Mays David C.,
Wang ChiYuen
Publication year - 2012
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/2011rg000382
Subject(s) - permeability (electromagnetism) , geology , geothermal gradient , poromechanics , induced seismicity , geotechnical engineering , porous medium , geophysics , seismology , chemistry , porosity , biochemistry , membrane
Oscillations in stress, such as those created by earthquakes, can increase permeability and fluid mobility in geologic media. In natural systems, strain amplitudes as small as 10 −6 can increase discharge in streams and springs, change the water level in wells, and enhance production from petroleum reservoirs. Enhanced permeability typically recovers to prestimulated values over a period of months to years. Mechanisms that can change permeability at such small stresses include unblocking pores, either by breaking up permeability‐limiting colloidal deposits or by mobilizing droplets and bubbles trapped in pores by capillary forces. The recovery time over which permeability returns to the prestimulated value is governed by the time to reblock pores, or for geochemical processes to seal pores. Monitoring permeability in geothermal systems where there is abundant seismicity, and the response of flow to local and regional earthquakes, would help test some of the proposed mechanisms and identify controls on permeability and its evolution.