Abstract
Changes in Vp/Vs (Poisson's ratio) around a fault are related to changes in the fluid transport properties of rocks, which play a significant role in seismogenic processes. Here we report a notable relationship between Vp/Vs and the permeability of porous fault-related rocks (Chelungpu fault, Taiwan) by direct and simultaneous measurement of elastic wave velocities (Vp and Vs) and permeability under increasing effective confining pressure (Peff) up to 25 MPa. Vp and Vs for all samples increased with Peff in the range up to 20 MPa, then were nearly constant as Peff increased to 25 MPa. Most silty sandstones with large proportions of fine-grained material showed positive correlations between Vp/Vs and permeability with rising pressure. On the other hand, well-sorted sandstones showed only slight changes in permeability with respect to Vp/Vs with rising pressure. We infer that grain size distributions, in particular the amount of silt- and clay-size grains, are responsible for the change in permeability with pressure as small particles clog pore networks with increasing Peff, causing the decrease in permeability. These findings may be useful to explain changes in permeability and pore pressure in the deep crust.
| Original language | English |
|---|---|
| Pages (from-to) | 1148-1160 |
| Number of pages | 13 |
| Journal | Geophysical Journal International |
| Volume | 182 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sep 1 2010 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Geophysics
- Geochemistry and Petrology
Cite this
Effects of pressure on pore characteristics and permeability of porous rocks as estimated from seismic wave velocities in cores from TCDP Hole-A. / Kitamura, Keigo; Takahashi, Miki; Mizoguchi, Kazuo; Masuda, Koji; Ito, Hisao; Song, Sheng Rong.
In: Geophysical Journal International, Vol. 182, No. 3, 01.09.2010, p. 1148-1160.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Effects of pressure on pore characteristics and permeability of porous rocks as estimated from seismic wave velocities in cores from TCDP Hole-A
AU - Kitamura, Keigo
AU - Takahashi, Miki
AU - Mizoguchi, Kazuo
AU - Masuda, Koji
AU - Ito, Hisao
AU - Song, Sheng Rong
PY - 2010/9/1
Y1 - 2010/9/1
N2 - Changes in Vp/Vs (Poisson's ratio) around a fault are related to changes in the fluid transport properties of rocks, which play a significant role in seismogenic processes. Here we report a notable relationship between Vp/Vs and the permeability of porous fault-related rocks (Chelungpu fault, Taiwan) by direct and simultaneous measurement of elastic wave velocities (Vp and Vs) and permeability under increasing effective confining pressure (Peff) up to 25 MPa. Vp and Vs for all samples increased with Peff in the range up to 20 MPa, then were nearly constant as Peff increased to 25 MPa. Most silty sandstones with large proportions of fine-grained material showed positive correlations between Vp/Vs and permeability with rising pressure. On the other hand, well-sorted sandstones showed only slight changes in permeability with respect to Vp/Vs with rising pressure. We infer that grain size distributions, in particular the amount of silt- and clay-size grains, are responsible for the change in permeability with pressure as small particles clog pore networks with increasing Peff, causing the decrease in permeability. These findings may be useful to explain changes in permeability and pore pressure in the deep crust.
AB - Changes in Vp/Vs (Poisson's ratio) around a fault are related to changes in the fluid transport properties of rocks, which play a significant role in seismogenic processes. Here we report a notable relationship between Vp/Vs and the permeability of porous fault-related rocks (Chelungpu fault, Taiwan) by direct and simultaneous measurement of elastic wave velocities (Vp and Vs) and permeability under increasing effective confining pressure (Peff) up to 25 MPa. Vp and Vs for all samples increased with Peff in the range up to 20 MPa, then were nearly constant as Peff increased to 25 MPa. Most silty sandstones with large proportions of fine-grained material showed positive correlations between Vp/Vs and permeability with rising pressure. On the other hand, well-sorted sandstones showed only slight changes in permeability with respect to Vp/Vs with rising pressure. We infer that grain size distributions, in particular the amount of silt- and clay-size grains, are responsible for the change in permeability with pressure as small particles clog pore networks with increasing Peff, causing the decrease in permeability. These findings may be useful to explain changes in permeability and pore pressure in the deep crust.
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UR - http://www.scopus.com/inward/citedby.url?scp=77955748497&partnerID=8YFLogxK
U2 - 10.1111/j.1365-246X.2010.04694.x
DO - 10.1111/j.1365-246X.2010.04694.x
M3 - Article
AN - SCOPUS:77955748497
VL - 182
SP - 1148
EP - 1160
JO - Geophysical Journal International
JF - Geophysical Journal International
SN - 0956-540X
IS - 3
ER -