SS: The Future of Seismic Imaging; Reverse Time Migration and Full Wavefield Inversion - Subsalt Imaging Using TTI Reverse Time Migration
Notice bibliographique
Résumé
Abstract The development of reverse time migration (RTM) and the availability of wide-azimuth data have significantly increased our ability to image subsalt. Much of this potential, however, remains to be developed by seismic imagers. One area for future development is the incorporation of anisotropy in subsalt imaging. Most anisotropic imaging involves vertical transverse isotropy (VTI), while tilted transverse isotropy (TTI) is generally overlooked. Shale that overlies the dipping salt flanks can cause TTI anisotropy issues. This type of geometry is common in the Deepwater Gulf of Mexico, particularly around salt-withdrawal minibasins. Ignoring the tilted symmetry not only causes image blurring and mispositioning of the salt flank, but also degrades and distorts the base of salt and subsalt images. RTM for isotropic and VTI has been routinely used, but the applications of RTM in a 3D heterogeneous TTI medium is still in its infancy. This lag is the result of difficulties in numerical formulations for non-vertical symmetric axes and the subsequent instabilities. The TTI implementation also carries much higher computational costs than those of isotropic and VTI cases. With the demonstration of its benefits and the advances in computing power, the usage of TTI RTM is expected to increase significantly. Initial applications of TTI RTM used narrow-azimuth, towed-streamer data. The lack of azimuthal information limited the ability to derive the velocity and corresponding anisotropic parameters. More accurate TTI parameters were derived and the benefits of TTI imaging were obtained only when two orthogonal narrow-azimuth datasets were processed simultaneously. The advent of wide-azimuth data in the Deepwater Gulf of Mexico further opens the door for TTI imaging. This is because the wide-azimuth data contains more abundant azimuthal information than either narrow-azimuth or multiple narrow-azimuth datasets. Topics related to TTI RTM remain a focus within the seismic imaging community. Improving the derivation of TTI anisotropic parameters from wide-azimuth data and extending full wavefield inversion for TTI media are among the most active areas of study. Introduction Seismic imagers routinely apply TTI depth imaging technology to image structures that lie beneath dipping, anisotropic overburden in the Canadian Foothill (Vestrum and Vermeulen, 2004), North Sea (Hawkins et al, 2002) and Offshore West Africa (Ball, 1995). Until now, ray-based migration algorithms served as the only choice for TTI imaging, because upgrading ray-based imaging algorithms for TTI is straightforward and incurs minor additional computational cost. Unlike ray-based algorithms, TTI wave-base algorithms are difficult to formulate and their implementations are often unstable and computationally intensive. Unfortunately, ray-based algorithms perform poorly in comparison to wave-based algorithms in imaging structures beneath such complex overburden as the subsalt in the Gulf of Mexico. This impedes the use of TTI imaging for subsalt in the Gulf of Mexico. The lack of appropriate checkshots and offset VSPs that can be used to constraint anisotropic parameters further discourages the utilization of TTI imaging in the Deepwater Gulf of Mexico.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».