2012
Elastic anisotropy of core samples from the Taiwan Chelungpu Fault Drilling Project (TCDP): direct 3-D measurements and weak anisotropy approximations
LOUIS, Laurent; Christian DAVID; Petr ŠPAČEK; Teng-fong WONG; Jerome FORTIN et. al.Základní údaje
Originální název
Elastic anisotropy of core samples from the Taiwan Chelungpu Fault Drilling Project (TCDP): direct 3-D measurements and weak anisotropy approximations
Autoři
LOUIS, Laurent (250 Francie); Christian DAVID (250 Francie); Petr ŠPAČEK (203 Česká republika, garant, domácí); Teng-fong WONG (840 Spojené státy); Jerome FORTIN (250 Francie) a Sheng Rong SONG (158 Tchaj-wan)
Vydání
Geophysical Journal International, 2012, 0956-540X
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10507 Volcanology
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 2.853
Kód RIV
RIV/00216224:14310/12:00059566
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000298586000016
Klíčová slova anglicky
Microstructures; Seismic anisotropy; Acoustic properties
Změněno: 9. 4. 2013 21:06, Ing. Andrea Mikešková
Anotace
V originále
The study of seismic anisotropy has become a powerful tool to decipher rock physics attributes in reservoirs or in complex tectonic settings. We compare direct 3-D measurements of Pwave velocity in 132 different directions on spherical rock samples to the prediction of the approximate model proposed by Louis et al. based on a tensorial approach. The data set includes measurements on dry spheres under confining pressure ranging from 5 to 200 MPa for three sandstones retrieved at a depth of 850, 1365 and 1394 metres in TCDP hole A (Taiwan Chelungpu Fault Drilling Project). As long as the P-wave velocity anisotropy is weak, we show that the predictions of the approximate model are in good agreement with the measurements. As the tensorial method is designed to work with cylindrical samples cored in three orthogonal directions, a significant gain both in the number of measurements involved and in sample preparation is achieved compared to measurements on spheres. We analysed the pressure dependence of the velocity field and show that as the confining pressure is raised the velocity increases, the anisotropy decreases but remains significant even at high pressure, and the shape of the ellipsoid representing the velocity (or elastic) fabric evolves from elongated to planar. These observations can be accounted for by considering the existence of both isotropic and anisotropic crack distributions and their evolution with applied pressure.
Návaznosti
CZ.1.07/2.3.00/20.0052, interní kód MU |
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