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Reverse-Time Modeling of Channelized Meandering Systems from Geological Observations Marion Parquer

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Reverse-Time Modeling of Channelized Meandering Systems from Geological Observations Marion Parquer Reverse-time modeling of channelized meandering systems from geological observations Marion Parquer To cite this version: Marion Parquer. Reverse-time modeling of channelized meandering systems from geological observa- tions. Applied geology. Université de Lorraine, 2018. English. NNT : 2018LORR0081. tel-01902547 HAL Id: tel-01902547 https://hal.univ-lorraine.fr/tel-01902547 Submitted on 5 Apr 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. AVERTISSEMENT Ce document est le fruit d'un long travail approuvé par le jury de soutenance et mis à disposition de l'ensemble de la communauté universitaire élargie. Il est soumis à la propriété intellectuelle de l'auteur. Ceci implique une obligation de citation et de référencement lors de l’utilisation de ce document. D'autre part, toute contrefaçon, plagiat, reproduction illicite encourt une poursuite pénale. Contact : [email protected] LIENS Code de la Propriété Intellectuelle. articles L 122. 4 Code de la Propriété Intellectuelle. articles L 335.2- L 335.10 http://www.cfcopies.com/V2/leg/leg_droi.php http://www.culture.gouv.fr/culture/infos-pratiques/droits/protection.htm Reverse-time modeling of channelized meandering systems from geological observations Modélisation rétro-chronologique de systèmes chenalisés méandriformes à partir d’observations géologiques T HÈSE présentée et soutenue publiquement le 5 avril 2018 pour l’obtention du grade de Docteur de l’Université de Lorraine Spécialité Géosciences par Marion PARQUER Composition du jury: Rapporteurs: Prof. Sylvie B OURQUIN Université de Rennes Prof. Clayton D EUTSCH University of Alberta Examinateurs: Dr. Isabelle C OJAN MINES ParisTech Prof. François M ÉTIVIER IPGP - Université Paris Diderot Dr. Zoltán S YLVESTER BEG - University of Texas Directeur de thèse: Prof. Guillaume C AUMON Université de Lorraine Co-directrice de thèse: Dr. Pauline C OLLON Université de Lorraine Invité: Jean-Loup R UBINO TOTAL GeoRessources – UMR 7359 Université de Lorraine – ENSG / CNRS / CREGU 2 rue du Doyen Marcel Roubault - BP 10162 54505 Vandœuvre-lès-Nancy, France Summary Meandering systems constitute the majority of aerial and subaquatic channels which shape the landscapes by their temporal and spatial evolution. The witnesses of this evolution can be observed on the plains crossed by these channels. Among them, lateral point bars result from the channel migration, abandoned meanders are created by the natural stream rectifying and abandoned channels originate from the main direction change by avulsion. Once buried, the channelized systems are good candidates for natural resources storage thanks to the diversity and the volume of the resulting deposits. The under- standing of the internal architecture of facies is thus crucial for resource exploitation. Satellite and LIDAR (Light Detection and Ranging) images permit current system studies. Subsurface architecture can be imaged by seismic or GPR (Ground Penetrat- ing Radar) images. These techniques give a good evaluation of the whole system of the last channel path. However, anterior stages, when spared by the erosion can only be observed locally. Indeed, the reworking of the channel belt by lateral and downstream migration makes it difficult to observe the geometrical or chronological features of anterior deposits. This thesis proposes a 3D reconstruction simulation method of channelized sys- tems conditioning to sparse and diverse available information. Among them, the subsurface imaging often permits to identify the last system stage and the abandoned meanders, thanks to their muddy filling after the abandonment time, contrasting with the channel belt. Lateral point bars can also be observed, witnessing of meander paleo-migration direction. Sometimes, well data inform on the facies (e.g., muddy, sandy). The method presented here starts from the last channel path observed on the seismic image and goes back in time by reverse migration to reconstruct anterior channel paths. This stochastic migration model is inspired by the analysis of historic Mississippi maps. According to a chronology simulation based on spatial and sta- tistical criteria (e.g., distance and orientation to the current channel, abandonment probability distribution), abandoned meanders are integrated at the relevant time step inside the main channel path. Erosion and difficulty of imaging of abandoned meanders is addressed by abandoned meander simulation inside the meander belt. iii This stochastic simulation conditions to geometrical criteria observed on the aban- doned meanders spared by the erosion but also to statistical criteria observed on sedimentary analogs such as the Mississippi river (e.g., erosion probability distribu- tion). One of the main perspectives is to condition to well data through the simulation of abandoned meanders. This technique has been applied on two satellite and seismic 2D case studies. Keywords channelized system migration abandoned meander stochastic simulation sedimentary record reservoir iv Résumé Les systèmes méandriformes constituent la plupart des rivières terrestres ou sub- aquatiques qui modèlent les paysages par leur évolution temporelle et spatiale. Les témoins de leur évolution peuplent les plaines traversées par ces systèmes. Parmi ces témoins, des barres d’accrétion latérale traduisant la migration des boucles du chenal peuvent être identifiées, tout comme des méandres abandonnés par simplification naturelle de la trajectoire du chenal ou encore des chenaux entiers abandonnés lors d’un changement de direction principale du chenal par avulsion. La diversité et le volume des dépôts résultant font des systèmes chenalisés, une fois enfouis, de bons candidats pour le stockage de ressources naturelles. L’étude de la disposition des différents faciès est donc cruciale pour leur exploitation. Les techniques d’imagerie satellitaire ou LIDAR (Light Detection and Ranging) per- mettent l’étude des systèmes actuels. L’architecture en subsurface peut être imagée par image sismique ou GPR (Ground Penetrating Radar), ou localement par des puits d’investigation. Ces techniques permettent d’avoir une bonne évaluation du dernier état du système chenalisé. Les états précédents, quant à eux, peuvent être observés par morceaux lorsqu’ils ont été épargnés par l’érosion. En effet, le remaniement de la ceinture de méandres par migration latérale des chenaux rend souvent difficile l’analyse des états antérieurs tant en matière de géométrie que de chronologie des dépôts. Cette thèse propose une méthode de simulation de reconstruction des systèmes chenalisés en trois dimensions qui respecte au mieux les informations disponibles de nature et d’échelle diverses. Parmi ces données, souvent, l’imagerie permet d’identi- fier le dernier état du système et des boucles de méandres abandonnés en contrastant avec la ceinture de méandres par des dépôts souvent plus argileux et datant de la période succédant l’abandon. Des barres d’accrétion latérale peuvent aussi être ob- servées, témoignant des directions de migration des méandres. Parfois, des données de puits sont accessibles et informent sur la nature des faciès rencontrés (p. ex., sableux, argileux). La méthode présentée dans ce manuscrit part du dernier état du système observé. Une simulation rétro-chronologique de la migration du chenal, ins- pirée par l’analyse des cartes chronologiques du Mississippi, est appliquée et permet, v pas de temps par pas de temps, de retrouver de potentiels états antérieurs. Selon une simulation de la chronologie estimée par des critères spatiaux et statistiques (p. ex., distance et orientation au chenal courant, probabilité d’abandon), les méandres abandonnés sont intégrés à l’étape de temps appropriée dans le chenal principal. Les boucles de méandres disparues par érosion ou invisibles à l’imagerie sont com- pensées par la simulation d’autres méandres dans la ceinture de méandres. Cette simulation respecte les critères géométriques observés sur les méandres épargnés par l’érosion mais également d’autres critères statistiques tels que la probabilité d’érosion observée sur des analogues sédimentaires (p.ex. le fleuve Mississippi). Cette approche ouvre la possibilité d’honorer les faciès observés sur les puits par la simulation de méandres abandonnés en ces points. Elle a été appliquée sur deux jeux de données bidimensionnels satellite ou sis- mique. Mots-clefs système chenalisé migration méandre abandonné simulation stochastique enregistrement sédimentaire réservoir vi Remerciements A certains égards, il est sûrement plus facile de passer sa soutenance de thèse que d’écrire ses remerciements mais c’est une tradition à laquelle je ne voudrais pas me dérober. En premier lieu j’aimerais remercier les membres de mon jury de thèse, à savoir Sylvie Bourquin, Isabelle Cojan, Clayton Deutsch, François Métivier, Jean-Loup Ru- bino et Zoltàn Sylvester pour avoir accepté d’évaluer ce travail et de l’avoir valorisé par des questions diverses et pertinentes lors de l’échange pendant ou avant la soute- nance. Je voudrais également remercier
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