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  • Characterization of overburden anisotropy improves wellbore stability in North Sea field

    Mehmet Fidan, Hardy Nielsen, Neil Anderson, Kristen Kozlowski, Adam Donald, Peter Shotton and Jeroen Jocker

    Borehole sonic data are traditionally used for both geophysical calibration and geomechanical modeling. However, in a strongly layered medium, compressional and shear sonic waves propagate at different speeds, depending on the orientation of the wellbore relative to bedding. This phenomenon, known as elastic anisotropy, is especially common in shale formations, where constituent plate-shaped clay particles are often oriented parallel to one another. When shales exhibit a vertical axis of symmetry roughly orthogonal to layering, they can be described by a form of elastic anisotropy known as transverse isotropy (TI).

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2013 Fracturing Technology

2013 Fracturing Technology