Kinematics of common-image gathers — Part 1: Theory
| Autor: | Gilles Lambaré, Jean-Philippe Montel |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
Computer science business.industry Process (computing) Kinematics 010502 geochemistry & geophysics 01 natural sciences Image (mathematics) Geophysics Quality (physics) Geochemistry and Petrology Computer vision Ray tracing (graphics) Tomography Artificial intelligence business 0105 earth and related environmental sciences |
| Zdroj: | GEOPHYSICS. 84:S437-S447 |
| ISSN: | 1942-2156 0016-8033 |
| DOI: | 10.1190/geo2018-0706.1 |
| Popis: | Common-image gathers are a useful output of the migration process. Their kinematic behavior (i.e., the way they curve up or down) is an indicator of the quality of the velocity model used for migration. Traditionally, when used for migration velocity analysis, we pick structural dips in the common attribute panels (offset, angle, etc.) and residual moveout (RMO) in the gathers. The measured RMO will then tell us how much we need to update the velocity model to improve the gather’s flatness. Understanding the kinematics of the picked events is the key to an accurate model update. This point has been widely underestimated in many cases. For example, when dealing with angle gathers, there is a general assumption that the associated tomographic rays are fully defined by the picked structural dips and the gather opening and azimuth angle, and that if the velocity model is correctly updated down to a given horizon, it is not necessary to shoot the tomographic rays upward through this horizon. We find through an original theoretical analysis that both of these assumptions have to be modified when the gathers exhibit RMO. Using a kinematic analysis, we determine that knowledge of the RMO slopes is necessary to compute the tomographic rays. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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