ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Most rocks are saturated or partly saturated with different fluids under different depth,temperature and pressure conditions. It is generally acknowledged that fluids have the mostimportant effect on the attenuation and dispersion of seismic waves. There exists a relation betweenfrequency- and temperature- dependence on rock’s seismic properties. It is not yet clear in literaturewhether there exist other equally important attenuation mechanisms as that in Biot’s model, sincethere are other sources of dissipation, also related to fluids, that are not considered in Biot theorybut that may also contribute to the overall dissipation of seismic energy. Identifying the preciserelaxation mechanisms is still the subject of experimental and theoretical research. In this article, aseries of experiments are conducted on dry and saturated rocks (sandstone, marble, granite) atdifferent temperatures and frequencies to find the attenuation mechanism of interaction betweenrock skeleton and pore-fluid. Fluid viscosity generally depends on temperature, so the effect of porefluid on attenuation is confirmed in terms of apparent viscosity variation of rock caused by thechange of pore-fluid conditions (such as frequency or temperature). Based on our experimentaldata, we develop a new model of macroscopic apparent viscosity in saturated rock which isconsistent with the nonlinear relaxation law. It helps to derive the analytical expressions to computevelocity dispersion and attenuation as functions of frequency and temperature
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.326-328.1149.pdf
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