Petrophysical study of faults in sandstone using petrographic image analysis and X-ray computerized tomography

Antonellini, Marco; Aydin, Atilla; Pollard, David D.; D'Onfro, P. S.

doi:10.1007/bf00874328

Cited by 45 publications

(12 citation statements)

References 23 publications

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“…The spatial variability of soil properties is determined by the soil formation history, and it is readily observed in in situ test data (Tang, 1979;Harr, 1987;Kulhawy, 1992;Ravi, 1992;DeGroot & Baecher, 1993;Hegazy et al, 1996;Lacasse & Nadim, 1996;Phoon & Kulhawy, 1999), petrographic image analysis (Antonellini et al, 1994a), digital image correlation analyses of triaxial tests (Rechenmacher et al, 2005;Rechenmacher & Medina-Cetina, 2007), cross-sectional images of impregnated soils (Jang et al, 1999), X-ray tomography (Antonellini et al, 1994b) and electrical needle probe profiles (Cho et al, 2004). The consequences of spatial variability for the quasi-static resistance (Yoshida et al, 1993;Vaid et al, 1995;Hoeg et al, 2000;Vaid & Sivathayalan, 2000) and the dynamic resistance are extensively documented (Ladd, 1974;Mulilis et al, 1975;Townsend, 1978;Ishihara, 1993;Popescu et al, 1997Popescu et al, , 2005.…”

Section: Introductionmentioning

confidence: 99%

Spatial variability: drained and undrained deviatoric load response

Kim

Santamarina

2008

Géotechnique

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Geotechnical properties vary in space. Geostatistical parameters such as the mean, the standard deviation and the correlation length are characteristic for each sediment and formation history. The effects of spatial variability on the drained and undrained shear response of soils are investigated using numerical parametric studies where multiple realisations are tested for selected geostatistical parameters. Results show that the mean undrained shear strength decreases as spatial variability and correlation length increase. Spatial variability prompts strain localisation along neighbouring weak zones under both drained and undrained loading. Heterogeneous contractive media show internal homogenisation during drained deviatoric loading, and the drained shear resistance evolves towards the critical state; media with higher variability and longer correlation length require higher strain to attain internal homogenisation. Anisotropy in spatial correlation causes anisotropy in shear strength. An intermediate drainage condition emerges in spatially varying media whereby local drainage may develop during globally undrained shear; local drainage affects the load-deformation response.

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Section: Introductionmentioning

confidence: 99%

Spatial variability: drained and undrained deviatoric load response

Kim

Santamarina

2008

Géotechnique

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“…The CT-scanner measures the X-ray attenuation coefficient, which increases with increasing bulk density and atomic number (WELLINGTON and VINEGAR, 1987;ANTONELLINI et al, 1994). The CT-scanner measures the X-ray attenuation coefficient, which increases with increasing bulk density and atomic number (WELLINGTON and VINEGAR, 1987;ANTONELLINI et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

Failure Mode and Spatial Distribution of Damage in Rothbach Sandstone in the Brittle-ductile Transition

Bésuelle

Baud

Wong

2003

Pure appl. geophys.

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To elucidate the spatial complexity of damage and evolution of localized failure in the transitional regime from brittle faulting to cataclastic ductile flow in a porous sandstone, we performed a series of triaxial compression experiments on Rothbach sandstone (20% porosity). Quantitative microstructural analysis and X-ray computed tomography (CT) imaging were conducted on deformed samples. Localized failure was observed in samples at effective pressures ranging from 5 MPa to 130 MPa. In the brittle faulting regime, dilating shear bands were observed. The CT images and stereological measurements reveal the geometric complexity and spatial heterogeneity of damage in the failed samples. In the transitional regime (at effective pressures between 45 MPa and 130 MPa), compacting shear bands at high angles and compaction bands perpendicular to the maximum compression direction were observed. The laboratory results suggest that these complex localized features can be pervasive in sandstone formations, not just limited to the very porous aeolian sandstone in which they were first documented. The microstructural observations are in qualitative agreement with theoretical predictions of bifurcation analyses, except for the occurrence of compaction bands in the sample deformed at effective pressure of 130 MPa. The bifurcation analysis with the constitutive model used in this paper is nonadequate to predict compaction band formation, may be due to the neglect of bedding anisotropy of the rock and multiple yield mechanisms in the constitutive model.

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“…In non-conventional (fractured hard rock) reservoirs, the porosity relates to the fracture properties of the rock, which can also be investigated by CT methods. A combination of breaking tests and CT scanning was applied by Raynaud et al (1989) (Antonellini et. al, 1994) or in granite (Kawakata, 1999) with CT.…”

Section: Ct Applications In Geologymentioning

confidence: 99%

Integrated core study of a fractured metamorphic HC-reservoir; Kiskunhalas-NE, Pannonian Basin

et al. 2013

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The petrologic interpretation of the coexisting lithologies in the KIHA-NE metamorphic block suggests that two of the four rock units may have a significant role in the migration and/or storage of hydrocarbons. The strongly sheared mylonite samples exhibit remarkable fracture systems with clear evidence of one-time oil migration. In the course of the integrated core study, in addition to the petrological methods, 3D CT scans and destructive and non-destructive rock mechanical treatments were fulfilled on representative samples and evaluated. On the basis of the results we can state that the petrologically different rock types have remarkably different brittle behaviours. The orthogneiss mylonite is characterised by moderate anisotropy and fracture tendency. However, the fractal dimension and cumulative fracture length values do not suggest the formation of complicated and connected fracture systems. High anisotropy and a large and possibly communicating fracture system characterise the graphitic gneiss mylonite, achieved by a much lower work investment than for any other rock type.

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Petrophysical study of faults in sandstone using petrographic image analysis and X-ray computerized tomography

Cited by 45 publications

References 23 publications

Spatial variability: drained and undrained deviatoric load response

Spatial variability: drained and undrained deviatoric load response

Failure Mode and Spatial Distribution of Damage in Rothbach Sandstone in the Brittle-ductile Transition

Integrated core study of a fractured metamorphic HC-reservoir; Kiskunhalas-NE, Pannonian Basin

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