The interaction of tube waves with borehole fractures, Part II: Analytical models
| Autor: | Brian E. Hornby, Sergio Kostek, Kenneth W. Winkler, David Linton Johnson |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | GEOPHYSICS. 63:809-815 |
| ISSN: | 1942-2156 0016-8033 |
| DOI: | 10.1190/1.1444392 |
| Popis: | We solve, numerically, the equations of elastodynamics that govern the propagation of waves in a fluid‐filled borehole intersected by one or more fluid‐filled fractures, thus extending earlier work on formations presumed to be rigid. The model is axis symmetric, and it allows for arbitrary radial and vertical variations in the elastic properties of the formation. We have developed a novel gridding scheme that takes advantage of the assumed thinness of the fracture compared to any relevant wavelength; this technique obviates the necessity for a mesh within the fracture itself and thereby saves computational time and memory. We illustrate our technique by means of examples with single and double fractures with or without washouts, as well as examples with variable width fractures. We compute the frequency‐dependent reflection and transmission coefficients of tube waves by fractures from the time waveforms generated by the present method. Major conclusions of this work are (1) reflections of tube waves by fr... |
| Databáze: | OpenAIRE |
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