| Autor: |
Jean-Luc Mari, Manuela Mendes |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
Near Surface Geophysics. 10:185-195 |
| ISSN: |
1569-4445 |
| DOI: |
10.3997/1873-0604.2011052 |
| Popis: |
Tomographic inversion helps to generate detailed geophysical models of the subsurface. This paper shows how the velocity model obtained by the conventional Plus-Minus refraction travel-time picking method can be used as initial input in a subsequent refraction tomography to build an even more accurate subsurface velocity model. This new fast procedure becomes an interesting alternative technique considering the important computational time effort required for the global search algorithms or the simple two-layered model provided by the conventional refraction analysis, as the Plus-Minus method. The proposed methodology proved attractive when testing with synthetic and field data. The illustration with synthetic data shows the final result and reference model very well matched. It is shown that the ray coverage is a useful tool for assessing the quality of the reconstructed model. The application to field data enables us to map the irregular shape of the top of a karstic reservoir, to be sure that no cavities filled with clays are present near there (top of the reservoir) to obtain a 3D velocity-depth model of a heterogeneous low velocity superficial zone revealing the main orientation of fracture corridors (N90°), and also to estimate appropriate static corrections for use in subsequent data processing. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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