The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Razi P. - One of the best experts on this subject based on the ideXlab platform.
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Forward Seismic modeling as a guide improving detailed Seismic Interpretation of deltaic systems: Example of the Eocene Sobrarbe delta outcrop (South-Pyrenean foreland basin, Spain), as a reference to the analogous subsurface Albian Cenomanian Torok-
Elsevier B.V., 2021Co-Authors: Grasseau N., Grélaud C., López Blanco Miguel, Razi P.Abstract:A forward Seismic model of the Middle Eocene Sobrarbe delta outcrop (South-Pyrenees, Spain) has been made to investigate its Seismic signature. The Sobrarbe delta complex corresponds to a syntectonic sedimentary wedge locally thicker than 1000 m. This 15 km-long, highly-progradational and moderately aggradational sedimentary system presents sigmoid and oblique clinoforms, characterized by slopes ranging from 0.2° to 5.7°. Along the clinoforms, the classical deltaic depositional environments grade progressively from one to the other: alluvial plain, delta plain, delta front and prodelta. Locally, specific carbonate deposits occur, corresponding to transgressive pulses. The transition from delta front to prodelta is locally marked by large slide scars affecting clinoform morphology. A detailed outcrop transect of the Sobrarbe delta was converted to an acoustic impedance model by assigning petrophysical properties to each geological facies. This model was then used to create synthetic Seismic lines characterized by various input wavelets. The resulting various peak frequency synthetic Seismic lines have been interpreted, and the Seismic Interpretation compared to the outcrop description to calibrate the Seismic Interpretation and assess the 'limits' of that Interpretation. This work shows that the 'Seismic stratigraphy' methodology is consistent and allows the correct Interpretation of most Seismic sequences. However, composite reflections from rapid lateral facies transitions and higher-frequency sequence boundaries can clearly lead to Seismic Interpretation mistakes. The Seismic facies of seven facies associations have been described, providing guidelines to recognize them on actual Seismic lines. The synthetic Seismic image of four selected systems tracts comprising good reservoir bodies has been analyzed to highlight recognition criteria which can be used to interpret analog deltaic systems in the subsurface, and therefore enhance the prediction and characterization of the reservoir bodies that they hold. These guidelines were systematically applied to a direct subsurface analog: the Torok-Nanushuk Delta (Colville Basin, NPRA, USA)
Ugge, Aina Juell - One of the best experts on this subject based on the ideXlab platform.
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Aspects of automated Seismic Interpretation
2020Co-Authors: Ugge, Aina JuellAbstract:The Interpretation of Seismic data is an integrated process that requires geophysical knowledge and an intuitive geological understanding. While Seismic Interpretation is essential in order to accumulate knowledge and build an understanding of the subsurface, some elements of the Interpretation workflow can be tedious, subjective and in some cases even trivial. In this thesis, we present data-driven methods that seek to integrate data science and geoscience in order to address different aspects of automated Seismic Interpretation. The data-driven methods that we present are based on digital tools from image processing, signal processing and machine learning. With these methods, we aim to (1) identify and individualize faults and unconformities, (2) correlate and track non-coherent Seismic horizons, (3) identify stratigraphic units and (4) improve Seismic image quality
Grasseau Nicolas - One of the best experts on this subject based on the ideXlab platform.
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Architecture, dynamic and forward Seismic modelling of a syntectonic river-delta system : the Eocene deltaic complex means of Sobrarbe, foreland basin of South Pyrenees (Aragon, Spain)
2020Co-Authors: Grasseau NicolasAbstract:Dans le bassin d’avant-pays sud-pyrénéen, la continuité exceptionnelle des environnements de dépôts du complexe deltaïque éocène moyen du Sobrarbe permet d’observer l’architecture stratigraphique et sédimentaire d’un système fluvio-deltaïque syntectonique à différents échelles. L’objectif principal de cette étude est de déterminer l’origine des facteurs allogéniques et/ou autogéniques contrôlant la géométrie et la répartition des dépôts d’un tel système sédimentaire en contexte compressif, dans le but de pouvoir le comparer à d’autres systèmes deltaïques accumulés dans des contextes géologiques différents. Cette étude est basée sur l’acquisition d’une cartographie géologique détaillée et d’une soixantaine de logs sédimentologiques. La base de données est complétée par une actualisation de données chronostratigraphiques issues de la littérature, l’acquisition de données magnétostratigraphiques. L’analyse sédimentologique et stratigraphique du système sédimentaire aboutit à une description précise des géométries, des faciès et des processus physiques caractérisant les différents environnements de dépôt répartis au sein de deux modèles sédimentaires : un système fluvio-deltaïque de forte énergie développé pendant les phases progradantes, un système mixte gréso-carbonaté de basse énergie caractérisant les phases aggrado-progradantes et transgressives. L’analyse de trois transects de corrélation, d’orientation proximale-distale, a permis la distinction de trois ordres de séquence imbriqués : les séquences de cinquième ordre, les séquences de quatrième ordre et les séquences de troisième ordre. L’organisation complexe des différents cortèges de dépôts des séquences de quatrième et de troisième ordre reflète des variations d’accommodation provoquées principalement par les déformations structurales de différentes longueurs d’onde, secondairement par les variations eustatiques. Une analyse poussée des cortèges de dépôts permet une discussion sur les interrelations entre les trois paramètres majeurs qui contrôlent la dynamique du système sédimentaire dans le temps et dans l’espace: les variations du taux d’accommodation, du flux sédimentaire et l’influence des processus sédimentaires. Ces éléments fournissent des informations semi-quantitatives sur l’accumulation sédimentaire au sein des différents environnements de dépôt (source to sink). La synthèse des résultats aboutit à la reconstruction séquentielle de la paléogéographique du complexe deltaïque du Sobrarbe. Enfin; l’analyse de la subsidence du bassin d’Ainsa a permis de reconstituer l’évolution de la sédimentation et du bassin sédimentaire entre le Lutétien et l’Oligocène. Une étude intégrée affleurement-modélisation sismique synthétique-analogue réel de subsurface fournit une combinaison de données architecturales et dimensionnelles, qui est utilisée pour améliorer les interprétations sismiques des systèmes réservoirs fluvio-deltaïques. De telles études réduisent considérablement les incertitudes associées à la résolution des données de subsurface, ce qui permet une meilleure évaluation économique des réservoirs.In the South-Pyrenean foreland basin, the exceptional continuity of middle Eocene Sobrarbe deltaic complex deposit environments allows to observe the stratigraphic and sedimentary architecture of a syntectonic river-dominated delta system at different scales. The main objective of this study is to determine the origin of allogenic and/or autogenic factors that control the distribution of deposits of such sedimentary system in a compressive setting, in order to compare it to other deltaic systems that accumulate in different geological contexts. This study is based on the acquisition of detailed geological mapping and about sixty measured sections. The database is complemented by updating chronostratigraphic data from the literature and additional magnetostratigraphic data. Sedimentological and stratigraphic analysis of the sedimentary system leads to an accurate description of geometry, facies and physical processes of different depositional environments distributed along two sedimentary models: a high energy river-delta system developed during progradational phases, a low energy mixed siliciclastic-carbonate system characterizing the aggrado-progradational and transgressive phases. Three dip sections analysis allows the identification of three nested order sequence: fifth-order sequences, fourth-order sequences and third-order sequences. The complex organization of fourth and third-order sequences systems tracts reflects accommodation variations caused mainly by structural deformation at different scales, secondary by eustatic changes. An advanced systems tract analysis leads a discussion of interrelationships between three main parameters that control the dynamics in time and space of sedimentary system: changes in the accommodation rate, sediment input and the influence of sedimentary processes. These elements provide semi-quantitative information regarding to the sediment accumulation within the different depositional environments (source to sink). Summary of results leads to the sequential reconstruction of the Sobrarbe deltaic complex paleogeography. Subsidence analysis of the Ainsa basin permits to reconstruct the sedimentation and sedimentary basin evolution from Lutetian to Oligocene times. An integrated study of outcrop-forward Seismic modelling-real Seismic analog provides an architectural and dimensional data combination used to improve Seismic Interpretation of river-deltaic reservoir systems. Such studies greatly reduce the uncertainties associated with the resolution of subsurface data, enabling better economic assessment of reservoirs
Grasseau N. - One of the best experts on this subject based on the ideXlab platform.
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Forward Seismic modeling as a guide improving detailed Seismic Interpretation of deltaic systems: Example of the Eocene Sobrarbe delta outcrop (South-Pyrenean foreland basin, Spain), as a reference to the analogous subsurface Albian Cenomanian Torok-
Elsevier B.V., 2021Co-Authors: Grasseau N., Grélaud C., López Blanco Miguel, Razi P.Abstract:A forward Seismic model of the Middle Eocene Sobrarbe delta outcrop (South-Pyrenees, Spain) has been made to investigate its Seismic signature. The Sobrarbe delta complex corresponds to a syntectonic sedimentary wedge locally thicker than 1000 m. This 15 km-long, highly-progradational and moderately aggradational sedimentary system presents sigmoid and oblique clinoforms, characterized by slopes ranging from 0.2° to 5.7°. Along the clinoforms, the classical deltaic depositional environments grade progressively from one to the other: alluvial plain, delta plain, delta front and prodelta. Locally, specific carbonate deposits occur, corresponding to transgressive pulses. The transition from delta front to prodelta is locally marked by large slide scars affecting clinoform morphology. A detailed outcrop transect of the Sobrarbe delta was converted to an acoustic impedance model by assigning petrophysical properties to each geological facies. This model was then used to create synthetic Seismic lines characterized by various input wavelets. The resulting various peak frequency synthetic Seismic lines have been interpreted, and the Seismic Interpretation compared to the outcrop description to calibrate the Seismic Interpretation and assess the 'limits' of that Interpretation. This work shows that the 'Seismic stratigraphy' methodology is consistent and allows the correct Interpretation of most Seismic sequences. However, composite reflections from rapid lateral facies transitions and higher-frequency sequence boundaries can clearly lead to Seismic Interpretation mistakes. The Seismic facies of seven facies associations have been described, providing guidelines to recognize them on actual Seismic lines. The synthetic Seismic image of four selected systems tracts comprising good reservoir bodies has been analyzed to highlight recognition criteria which can be used to interpret analog deltaic systems in the subsurface, and therefore enhance the prediction and characterization of the reservoir bodies that they hold. These guidelines were systematically applied to a direct subsurface analog: the Torok-Nanushuk Delta (Colville Basin, NPRA, USA)
Grélaud C. - One of the best experts on this subject based on the ideXlab platform.
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Forward Seismic modeling as a guide improving detailed Seismic Interpretation of deltaic systems: Example of the Eocene Sobrarbe delta outcrop (South-Pyrenean foreland basin, Spain), as a reference to the analogous subsurface Albian Cenomanian Torok-
Elsevier B.V., 2021Co-Authors: Grasseau N., Grélaud C., López Blanco Miguel, Razi P.Abstract:A forward Seismic model of the Middle Eocene Sobrarbe delta outcrop (South-Pyrenees, Spain) has been made to investigate its Seismic signature. The Sobrarbe delta complex corresponds to a syntectonic sedimentary wedge locally thicker than 1000 m. This 15 km-long, highly-progradational and moderately aggradational sedimentary system presents sigmoid and oblique clinoforms, characterized by slopes ranging from 0.2° to 5.7°. Along the clinoforms, the classical deltaic depositional environments grade progressively from one to the other: alluvial plain, delta plain, delta front and prodelta. Locally, specific carbonate deposits occur, corresponding to transgressive pulses. The transition from delta front to prodelta is locally marked by large slide scars affecting clinoform morphology. A detailed outcrop transect of the Sobrarbe delta was converted to an acoustic impedance model by assigning petrophysical properties to each geological facies. This model was then used to create synthetic Seismic lines characterized by various input wavelets. The resulting various peak frequency synthetic Seismic lines have been interpreted, and the Seismic Interpretation compared to the outcrop description to calibrate the Seismic Interpretation and assess the 'limits' of that Interpretation. This work shows that the 'Seismic stratigraphy' methodology is consistent and allows the correct Interpretation of most Seismic sequences. However, composite reflections from rapid lateral facies transitions and higher-frequency sequence boundaries can clearly lead to Seismic Interpretation mistakes. The Seismic facies of seven facies associations have been described, providing guidelines to recognize them on actual Seismic lines. The synthetic Seismic image of four selected systems tracts comprising good reservoir bodies has been analyzed to highlight recognition criteria which can be used to interpret analog deltaic systems in the subsurface, and therefore enhance the prediction and characterization of the reservoir bodies that they hold. These guidelines were systematically applied to a direct subsurface analog: the Torok-Nanushuk Delta (Colville Basin, NPRA, USA)
