HR: 1330h
AN: T42A-0265    [PDF]
TI: Mechanical compaction of Bleurswiller sandstone : elastic wave velocities and permeability evolution
AU: * Fortin, J
EM: fortin@geologie.ens.fr
AF: Laboratoire de Geologie, ENS Paris, 24 rue Lhomond, Paris, 75005 France
AU: Schubnel, A
EM: schubnel@geologie.ens.fr
AF: Laboratoire de Geologie, ENS Paris, 24 rue Lhomond, Paris, 75005 France
AU: Schubnel, A
EM: schubnel@geologie.ens.fr
AF: Lassonde Institute, 170 College Street, Toronto, ON M5S 3E3 Canada
AU: Gueguen, Y
EM: gueguen@geologie.ens.fr
AF: Laboratoire de Geologie, ENS Paris, 24 rue Lhomond, Paris, 75005 France
AB: Field observations and laboratory experiments have recently documented in porous sandstones the development of compaction bands sub-perpendicular to the direction of maximum principal stress. These compaction bands have been preferentially observed in relatively homogeneous sandstones of high porosity, such as Bentheim sandstone studied by Wong et al. [2001] and Baud et al. [2003], but also in a heterogenous sandstone of high porosity, such as Diemelstadt sandstone Fortin et al. [2003]. Rock deformation, fluid transport, and acoustic velocity are coupled together. On one hand, Scott et al. [1993] showed that acoustic velocities across the brittle-ductile transition are clearly being affected. On the other hand the relation between permeability evolution and compaction of sandstone was demonstrated by Zhu et al [1999]. To understand better the complexity of damage resulting from compaction band formation and its effect on permeability, we performed series of experiments on Bleurswiller sandstone of porosity 25%. This vosgian sandstone is made of 50% quartz, 30% feldspars, and 20% of oxides and micas. Hydrostatic and conventional triaxial compression experiments were conducted at room temperature on saturated samples under drained conditions, with a constant pore pressure of 10 MPa. The samples were deformed in the range of confining pressure from 60 to 300 MPa Compressional wave velocities, shear waves velocity, and permeability have been measured during both hydrostatic and triaxial experiments.
DE: 5102 Acoustic properties
DE: 5104 Fracture and flow
DE: 5112 Microstructure
DE: 5114 Permeability and porosity
DE: 5139 Transport properties
SC: Tectonophysics [T]
MN: 2003 Fall Meeting