Abstract
The quality of the tomographic result is not good as expected because of the uneven ray coverage caused by increasing velocity contrast of the neighboring geological bodies and the inappropriate grid discretization in crosswell seismic first-break traveltime tomography. The tomographic results of physical and numerical models prove that when the velocity contrast is greater than 30.0%, its tomographic result will be deformed significantly, when between 30.0% and 15.0%, it will be acceptable, and when less than 15.0%, it will be very good. The multi-scale crosswell traveltime tomography is proposed on the above basis. The method is a simultaneous traveltime tomography using various grid discretizations for the same model to obtain velocity reconstructive images of a study area. The tomographic results of numerical and physical models show that this method simultaneously considers the resolution and accuracy of tomography and can significantly improve the quality of crosswell tomography. Even if the velocity contrast is more than 30.0%, multiscale tomographic results are still good. Therefore, this method can be applied to real crosswell seismic data tomography.
| Original language | English |
|---|---|
| Pages (from-to) | 915-922 |
| Number of pages | 8 |
| Journal | Acta Geophysica Sinica |
| Volume | 49 |
| Issue number | 3 |
| State | Published - May 2006 |
Keywords
- Accuracy
- Crosswell first-break traveltime tomography
- Grid discretization
- Multi-scale
- Ray coverage
- Resolution
- Velocity contrast