Physical modeling of anisotropic domains: Ultrasonic imaging of laser-etched fractures in glass
| Autor: | Mark E. Willis, Nikolay Dyaur, Robert R. Stewart, J. J. S. de Figueiredo, Bode Omoboya, Samik Sil |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | GEOPHYSICS. 78:D11-D19 |
| ISSN: | 1942-2156 0016-8033 |
| DOI: | 10.1190/geo2012-0075.1 |
| Popis: | Many regions of subsurface interest are, or will be, fractured. Seismically characterizing these zones is a complicated but essential task for resource development. Physical modeling, using ultrasonic sources and receivers over scaled exploration targets, can play a useful role as an analog for reservoir imaging and assessment. We explored the anisotropic response of glass blocks containing internal fractures created by a novel laser-etching technique. We compared transmitted and reflected signals for P- and S-waves from fractured and unfractured zones in a suite of ultrasonic (1–5 MHz) experiments. The unaltered glass velocities have averages of [Formula: see text] and [Formula: see text] for P- and S-waves, respectively (giving [Formula: see text]). The unfractured glass has a very high quality (Q) factor of over 500 for P-waves and S-waves. The fractured zones have a small (up to 1.5%) velocity decrease. Signals propagating through the fractured zone have diminished amplitudes and increased coda signatures. Reflection surveys (zero-offset and with variable polarizations) record significant scatter from the fractured zones. The fracture-scattered energy can be migrated to provide a sharper image. The glass specimens with laser-etched fractures display a rich anisotropic response, which can help inform field-scale imaging. |
| Databáze: | OpenAIRE |
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