Morphological Characterization of Induced Fracture in Sandstone Using X-ray Computed Tomography Scanning

ABSTRACT

Computed tomography (CT) scanning is one of the viable techniques to evaluate apertures of rough walled fractures. However, quantitative evaluation of small fracture apertures using CT data requires use of calibration curves. In this study, the increments of fracture apertures were physically measured using the DEMEC points and the integrated CT numbers across the fracture aperture were calculated from the CT data for development of the calibration chart. This method overcomes the difficulty in fabrication of perfectly smooth rock fractures for the calibration process. It was demonstrated that the calibration curve developed from this method could be used to characterize variable aperture fractures in sandstone within a certain accuracy. In addition, geostatistic tools were used to quantify any anisotropy in fracture aperture. Results reveal that the induced fracture in sandstone displays a high aperture variation and undulation with an anisotropy in aperture distribution.

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