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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Caracterização de reservatórios não convencionais Shale Gas na Formação Barreirinha Bacia do Amazonas / Shale Gas Reservoir characterization in Barreirinha Formation Amazonas Basin

Siana Soares de Oliveira 16 March 2015 (has links)
Os folhelhos pretos devonianos da Formação Barreirinha caracterizamse pela alta radioatividade na porção basal, grande extensão areal, espessura e profundidade de soterramento variável que vão de exposição na superfície até mais de 3000 m. Eles são as principais rochas geradoras do sistema petrolífero convencional da Bacia do Amazonas, e recentemente foram consideradas como promissores plays de gás não convencional. Folhelhos são geralmente caracterizados por uma matriz fechada, que faz com que sejam relativamente impermeáveis em relação ao fluxo de gás, a menos que ocorram fraturas, e dependendo das suas características geológicas e geoquímicas podem funcionar com um Sistema Petrolífero autossuficiente, atuando tanto como rocha fonte, quanto como reservatório de gás (reservatório Shale Gas). Assim, o gás natural termogênico ou biogênico gerado pode ser armazenado em folhelhos ricos em matéria orgânica na forma livre, adsorvida, ou em estado dissolvido. Em contraste com os sistemas petrolíferos convencionais, reservatórios Shale Gas, possuem mecanismos de aprisionamento e armazenamento únicos, sendo necessária a utilização de técnicas de avaliações específicas. No entanto, folhelhos prolíficos geralmente podem ser reconhecidos a partir de alguns parâmetros básicos: arquitetura geológica e sedimentar, propriedades geoquímicas e petrofísicas e composição mineralógica. Tendo em vista a carência de pesquisas de caráter descritivo, com cunho exploratório dos folhelhos geradores da Formação Barreirinha, esta dissertação tem como objetivo introduzir uma metodologia de identificação de intervalos de folhelho gerador com potencial para reservatório Shale Gas. Começando com uma investigação regional sobre o contexto geológico e sedimentar, seguido de uma avaliação abrangente enfocando as características geoquímicas, petrofísicas e litofácies dos folhelhos a partir da integração de parâmetros obtidos de perfis geofísicos de poço, análises geoquímicas e aplicação dos conceitos de Estratigrafia de Sequencia. / The Devonian black shale of Barreirinha formation is characterized by high radioactivity in the basal portion, large areal extension, thickness and depth of burial variable which ranges from exposure to surface to depth greater than 3000 m. This formation contains the main source rocks of conventional petroleum system of the Amazonas Basin, and recently were considered promising unconventional gas plays. Shales are generally characterized by a closed die, which makes them relatively impervious for gas flow unless fracturing occur, and depending on their geological and geochemical characteristics they might behave as a selfcontained Petroleum System, acting as both source rock and as a gas reservoir (Shale gas reservoir). Thus, the thermogenic or biogenic gas generated can be stored in shale rich in organic matter in free form, adsorbed or dissolved state. In contrast to conventional petroleum systems, Shale Gas reservoirs, have trapping mechanisms and unique storage, requiring the use of specific assessment techniques. However, prolific shale can usually be recognized based on some basic parameters: geological and sedimentary architecture, geochemical and petrophysical properties and mineralogical composition. Given the lack of descriptive research, about the exploration potential of the Barreirinha formations shale, this dissertation aims to introduce a methodology of identification of intervals that could be potential shale gas reservoirs. Starting with a regional research about the geological and sedimentary context, followed by a comprehensive review focusing on the geochemical characteristics, petrophysical and lithofacies based on the integration of the parameters obtained by well log, geochemical analysis and application of Sequence Stratigraphy concepts.
212

Evolução sedimentar da Formação Rio do Rasto na região centro-sul do Estado de Santa Catarina / Sedimentary evolution of Rio do Rasto Formation (Permian-Triassic of the Paraná basin) in the central-south portion of Santa Catarina State, Brazil

Lucas Verissimo Warren 31 March 2006 (has links)
A porção sul do supercontinente Gondwana, durante o intervalo de tempo compreendido entre o Neocarbonífero e o Eotriássico, é marcada por importantes eventos de ordem tectônica e sedimentar. Neste contexto, um ciclo de subsidência se desenvolveu acompanhando os movimentos da então denominada Orogenia Sanrafaélica, resposta da colisão do terreno Patagônico com a borda SW do Gondwana. O soerguimento das margens deste supercontinente propiciou a formação de um grande corpo d´água confinado, ou apresentando diminutas conexões oceânicas. A geração de novo e volumoso espaço de acomodamento possibilitou a acumulação de uma seqüência transgressivo-regressiva entre o neopermiano e o eotriássico da Bacia do Paraná. O caráter predominantemente progradacional da porção superior desta seqüência, culminou com a completa colmatação do corpo d´água, propiciando o desenvolvimento de sistemas deposicionais continentais ao final deste ciclo. Os sedimentos da Formação Rio do Rasto, objeto da presente dissertação, se inserem neste contexto e são caracteristicamente representativos dos depósitos de trato de mar alto desenvolvidos nos estágios terminais da evolução desta seqüência de segunda ordem, denominada ?Gondwana I? (Milani, 1997). A área de estudo da presente dissertação compreende a porção centro-sul e leste do Estado de Santa Catarina, englobando a carta topográfica do município de Lages e as serras do Rio do Rasto, Rio do Sul e Espigão, localizadas nas escarpas a leste do estado homônimo. Nesta região ocorrem rochas das unidades paleozóicas e mesozóicas na Bacia do Paraná, litoestratigraficamente pertencentes aos Grupos Tubarão, Guatá, Passa Dois e São Bento. A Formação Rio do Rasto caracteriza-se por aflorar muito bem na área estudada, possibilitando o levantamento de seções contínuas e o estudo detalhado de afloramentos sob a ótica da análise de fácies, elementos arquiteturais e análise de paleocorrentes. A Formação Rio do Rasto encontra-se encerrada por contatos de caráter transicional com as formações Teresina na base e Pirambóia no topo. É composta, litoestratigraficamente, pelos membros Serrinha e Morro Pelado, que perfazem, na área de estudo, espessuras máximas da ordem de 250 metros. De modo geral, a unidade caracterizase por seu caráter predominantemente progradacional, com a tendência de aumento de estratos de arenitos para o topo. Os sedimentos da porção basal da unidade, pertencentes ao Membro Serrinha, caracterizam-se pela presença de fácies heterolíticas, pelíticas e de coloração acinzentada, depositadas em condições de costa-afora. A ocorrência de elementos arquiteturais constituídos por arenitos com estrutura hummocky, swalley e laminação cruzada por onda é indicativa da deposição a partir de eventos pontuados de elevado grau energético. Concentrações fossilíferas compostas por dentes, escamas e coprólitos de peixes, aqui classificadas com bone beds, apresentam afinidades tafonômicas com depósitos originados por tempestades. Intercaladas a esta associação, ocasionalmente ocorrem camadas métricas lenticulares e sigmoidais de arenitos finos, interpretadas como depósitos de barras de desembocadura deltaica. Para o topo da unidade ocorre a mudança na coloração das fácies pelíticas cinzas para termos de coloração avermelhada e roxa, bem como o predomínio de elementos arquiteturais tipicamente deltaicos, como depósitos de baías, canais interdistributários e vi lobos de rompimento de diques marginais. Elementos arquiteturais eólicos ocorrem intercalados nas porções superiores do Membro Morro Pelado. A ocorrência de associações de fácies depositadas em diferentes posições fisiográficas dentro de um contexto deltaico pode ser expressa na alternância de elementos arquiteturais distais e proximais em todos os exemplos estudados. Esta particularidade pode ser parcialmente explicada pelo caráter fortemente autocíclico esperado em sistemas deposicionais deltaicos, o que propicia a migração constante dos canais, e conseqüentemente das áreas de baía interdistributários e desembocadura. Além da autociclicidade, outro fator determinante na construção do padrão arquitetural observado, é a variação das taxas de subida do nível relativo do mar. Ressalta-se que, inserido em um contexto maior de trato de mar alto, a tendência de desaceleração de subida do nível do mar é sempre esperada. Esta variação, ocorrendo em freqüência relativamente alta, propicia a variação na geração de espaço de acomodamento, determinando aumentos ou diminuições na razão entre aporte sedimentar e abertura de espaço. Desta maneira, quando a razão apresenta valores positivos desenvolve-se um padrão sedimentar progradacional, com conseqüente regressão da linha de costa. Valores negativos, materializados em maior taxa de geração de espaço de acomodação, em relação ao aporte sedimentar, propicia a formação de sucessões de arquitetura retrogradacional e transgressão da linha de costa. Conforme o sistema deltaico progradava, o mar interior ia sendo paulatinamente colmatado, resultando na tendência geral de diminuição do espaço de acomodação de sedimentos. Nas porções inferiores da Formação Rio do Rasto (Membro Serrinha) este fato se expressa na diminuição dos depósitos de tempestade para o topo, ou seja, com o decréscimo volumétrico e em área do corpo d´água, diminui a possibilidade da atuação de ondas de tempestade e conseqüentemente, o retrabalhamento dos sedimentos deltaicos por estes. Os depósitos de tempestades praticamente não ocorrem nas porções superiores da unidade (Membro Morro Pelado), onde, portanto, estão preservadas camadas tabulares lateralmente contínuas, associadas ao desenvolvimento de fluxos hiperpicnais nas porções frontais das barras de desembocadura deltaicas. O preenchimento por sedimentos e a diminuição volumétrica do corpo aquoso não implicaram na compartimentação deste em diversos lagos de menor extensão. O padrão de empilhamento de elementos arquiteturais associado à escassez de níveis contínuos de paleossolo e superfícies erosivas regionais bem marcadas permitem refutar esta hipótese. Dada a continuidade das associações de fácies e recorrência de elementos arquiteturais, em toda a área estudada na presente dissertação, o Sistema Deltaico do Rio do Rasto possivelmente apresentava tamanho em área compatível com a escala de dezenas de milhares de quilômetros quadrados. Dados de paleocorrentes sugerem progradação do edifício deltaico de SE para NW. A ocorrência no segundo terço estratigráfico da unidade, de elementos arquiteturais eólicos intercalados, pode ser considerada uma evidência da transição para o sistema desértico Pirambóia. Os dados de paleoventos indicam tendência de migração do sistema de dunas para WNW, em direção concordante à estimada para a migração do Sistema Deltaico Rio do Rasto. A tendência de continentalização da bacia culmina com os depósitos da Formação Pirambóia, estratigraficamente localizada acima e em contato transicional com a Formação Rio do Rasto. / The south portion of the supercontinent Gondwana, during the time period between the neocarboniferous and the eotriassic, is marked by important events in tectonic and sedimentary order. In this context, a subsidence cycle developed itself along the movements of the then-nominated Sanrafaelic Orogeny, the result of the collision between the Patagonic terrains with the southwestern border of Gondwana. The uplift of this supercontinent?s margins made possible the creation of a large confined body of water, or displaying small oceanic connections. The development of a new, large space of accommodation generated, then, the accumulation of a transgressive-regressive sequence between the neopermian and the eotriassic of Paraná Basin. The mainly progradational character of the upper portion of this sequence culminated with the complete filling of the body of water, allowing the development of depositional continental systems at the end of this cycle. The sediments of the Rio do Rasto formation, object of the present dissertation, are inserted in this context and characteristically representative of the highstand system tract deposits that developed in the terminal stages of this second-order sequence, named ?Gondwana I?(Milani, 1997). The study area of the present dissertation comprehends the central-southern and the eastern portion of the state of Santa Catarina, including the topographic chart of the Lages province e the Rio do Rasto, Rio do Sul and Espigão sierras, located in the eastern cliffs of the homonymous state. In this region, rocks of the paleozoic and mesozoic units of Paraná?s Basin occur, which lithostratigraphically are part of the Tubarão, Guatá, Passa Dois and São Bento groups. The Rio do Rasto formation is notable for an outcropping in the studied area, making possible the uplifting of the continued sessions and the detailed study of the outcrops under the view of the facies analysis, architectural elements and the paleocurrents analysis.The Rio do Rasto formation is surrounded in contacts of transitional character with the the Teresina formation, at the base, and Pirambóia formation at the top. It is composed, lithostratigraphically, by the Serrinha and Morro Pelado members, that present, in the studied área, maximum thickness of 250 meters. Generally, the unit is marked by its predominant progradational character, with the tendency of sandstones strata increasing to the top. The sediments of the base portion of the unit, from the Serrinha member, are characterized by the presence of heterolithic, pelithic and gray-colored facies, deposited in offshore conditions. The occurrence of sandstone-based architectural elements with hummocky structure, swalley and cross-lamination by waves, is indicative of the deposition from high energetic degree events. Fossil concentrations composed of teeth, scales e fish coprolites, here classified as bone beds, present tafonomic similarities with the stormgenerated deposits. Interbedded to this association, lenticular and sigmoidal metric layers from thin sandstones occasionally occur, interpreted as deltaic mouth bars deposits. At the top of the unit, the change of the gray pelithic facies coloration to red and purple tonalities occurs, as well as the predominance of typically deltaic architectural elements, such as basin deposits, interdistributary channels e crevasse splay lobes. Eolian architectural elements occur interbedded on the upper portions of the Morro Pelado member. The occurrence of associations of deposited facies in different physiographic positions inside a deltaic context, can be expressed in the alternation of nearshore and offshore architectural elements in all of the studied examples. This particularity can be partially explained by the strong auto cyclic character expected in deltaic depositional systems, which allows the constant migration of the channels, and consequentially of the interdistributary bay areas and deltaic mouths. Aside from the autocyclicity, another determinant factor in the interbedding of architectural elements is the variation of relative sea level rates, inside a larger context of highstand system tract, where the tendency of deceleration in the sea level rising speed is expected. This variation, occurring in relatively high frequency, makes possible the variation in the accommodation space generation, determining increasing and decreasing on the reason between sedimentary in-fill and the generation of acomodation space. Hence, when the reason presents positive values, a sedimentary progradational character is developed, with consequent regression of the coast line. Negative values, expressed in a bigger rate of accommodation space generation, compared to the sedimental aport, make possible the formation of retrogradational architecture successions and a transgression of the coast line. As the deltaic system progrates, the inner sea is gradually filled, materializing the general tendence of a shrinking in the accommodation space of sediments. In the lower portions of the Rio do Rasto formatiom (Serrinha member), this fact is expressed in the smaller presence of storm deposits to the top, which means that with the reduction of the body of water area, the possibility of reworking of the deltaic sediments through certain high energetic level events is diminished. The storm deposits do not occur on the upper portions of the unit (Morro Pelado member), where, as a result, the horizontally continuous tabular layers are preserved, associated to the development of hyperpicnal fluxes on the frontal portions of the deltaic mouth bars. The filling by sediments and the diminishing in volume of the water body do not result in its compartmentation in several smaller lakes. The pattern of the vertical succession of architectural elements associated to the shortage of continuous levels of paleosoils and marked regional erosive surfaces, allows one to deny this hypothesis. Given the continuity of the deltaic elements in all of the area studied in the present dissertation, the deltaic system of Rio do Rasto possibly presented a size, in area, compatible with the scale of thousands of square kilometers. Data of paleocurrents suggest progradation of the deltaic building from S/SE to N/NW. The occurrence of eolian architectural elements interbedded with sub aquatically deposited sediments, on the second stratigraphic third of the unit, can be considered an evidence of transition to the Pirambóia desert system. The paleoevents data indicate a migration tendence of the dune system to the NW, in a similar direction to the estimated for the Rio do Rasto deltaic system migration. The continentalization tendence of the basin results in the eolic deposits of the Pirambóia formation, stratigraphically located above and in transitional contact with the Rio do Rasto formation.
213

Sedimentology and sequence stratigraphy of the Jurassic, Jabal Tuwaiq, Central Saudi Arabia / Sédimentologie et stratigraphie séquentielle des séries jurassiques du Jabal Tuwaiq, Arabie Saoudite

Al-Mojel, Abdullah 01 December 2017 (has links)
Cette étude porte sur l’analyse des séries jurassiques du Shaqra Group (Toarcian to Kimmeridgian) qui affleurent de manière continue en Arabie centrale le long d’un transect de plus de 1000 km de long. Ces séries se sont accumulées sur une vaste plate-forme épicontinentale peu profonde, en contexte tropical. Ces affleurements permettent ainsi d’observer la partie occidentale des séries renfermant des systèmes pétroliers prolifiques exploités en subsurface en Arabie Saoudite. L’analyse sédimentologique de nombreuses coupes et la réalisation de corrélations stratigraphiques de haute résolution sur un transect de 600 km au sud de Riyad, complété par des corrélations avec les données de forage plus à l’est (entre Riyadh et le Rimthan Arch), permettent de distinguer une organisation séquentielle à différents ordres de fréquence et de reconstituer l’évolution de la plate-forme au sein de ces séquences. La plate-forme jurassique évolue d’une plate-forme horizontale caractérisée par des systèmes mixtes à la transition continental-marin du Toarcien au Callovien moyen (formations Marrat et Dhruma) vers un système de type rampe - bassin intrashelf du Callovien au Kimméridgien inférieur (formations Tuwaiq et Hanifa) pour finir par une plate-forme aggradante carbonatée et silico-clastique (Fm. Jubaila) puis carbonatée et évaporitique en contexte aride (Fm. Arab) au Kimméridgien. Les cycles tectono-stratigraphiques de 2ème ordre du Jurassique inférieur et moyen sont limités à la base et au sommet par des discontinuités régionales. Ils occupent un dépôt-centre stationnaire et décrivent un onlap côtier de grande ampleur avec un maximum transgressif au Callovien moyen (Upper Tuwaiq Mb.). Durant le Jurassique supérieur, les dépôts de rampe carbonatée de la Formation Hanifa passent progressivement vers l’ouest à des dépôts plus profonds de bassin intrashelf relativement riches en matière organique (Khurais - Rimthan Arch). La séquence Jubaila – Arab-D montre des variations d’épaisseur qui indiquent une déformation de grande longueur d’onde de la plate-forme arabe à cette période. Les faciès récifaux du membre Arab D sont interprétés comme représentant le maximum d’inondation de ce cycle qui se termine par le développement de systèmes carbonatés – évaporitiques à la fin du Jurassique. / They serve as westernmost reference for adjacent prolific reservoirs and source-rock bearing intrashelf basins. Several hierarchical sequences (second to fourth order) have been recognized in outcrops sections (600 km long south of Riyadh) and correlated with gamma-ray logs of subsurface wells (550 km long from Riyadh to Rimthan Arch). The Jurassic platform evolved from very-flat continental-to-nearshore mixed carbonate-siliciclastic platform (Marrat-Dhruma; Toarcian to Middle Callovian) to differentiated ramp with deep intrashelf basins (Tuwaiq-Hanifa; Callovian to Early Kimmeridgian) to a lowstand followed by flat aggraded platform (Jubaila-Arab-D; Kimmeridgian). Tectonic related siliciclastic influx took place in arid condition during the Kimmeridgian (Jubaila Fm.). The Jurassic platform ends with the mixed carbonate-evaporite systems of the Arab Fm. A first second-order tectono-eustatic cycle (Marrat to Tuwaiq) is bounded at the base and top by regional unconformities. It has a stationary depocenter, and show long-term coastal onlap and marine transgression that reached its maximum extent during the upper Tuwaiq (Middle Callovian). The Hanifa Fm. consists of four 3rd-order sequences aggraded flat-toped platform (outcrops to Khurais) marked at the base by argillaceous limestone and top by pure high-energy carbonates with localized reef buildups. The Jubaila Arab-D is two 3rd-order sequences begin with low-stand deposits followed by long-term transgression. These formed flat successions with lateral thickness variations controlled by differential subsidence increased in the Arabian Basin. The transgression is marked by storm-influenced inner-platform with sandstone quartz, grainstones and restricted lime-mudstone. The Maximum marine transgression is placed in the Arab-D with reef buildups in the westernmost inner-platform. During highstand, the reefs are gently prograding out into Rimthan Arch leaving behind restricted lagoon and sabkhah/salina anhydrite.
214

Étude stratigraphique, sédimentologique et paléogéographique des séries paléozoïques du nord du bassin de Ghadamès et de Jefarah en Libye et en Tunisie : caractérisation des réservoirs potentiels / Stratigraphy, sedimentology and paleogeography of a Paleozoic succession, Ghadames and Jefarah basin, Libya and Tunisia : characterization of potential reservoirs

Jabir, Adel 24 October 2017 (has links)
L’analyse stratigraphique et tectono-sédimentaire des séries sédimentaires du Paléozoïque qui remplissent le bassin de Ghadamès et son extension au nord, le bassin de Jefarah en Libye et en Tunisie, ont été étudiées. Ces formations appartiennent au cycle de Gondwana et sont, généralement, interprétées comme étant déposées dans un bassin cratonique tronqué par la discordance hercynienne. Cette étude est basée sur l’analyse des électrofaciès et des électroséquences dans plus de 130 puits. Les corrélations stratigraphiques entre puits sont basées sur la définition des cycles de 1er et de 2ème ordre. Cela a permis de comprendre l’évolution des environnements sédimentaires dans les deux bassins, de reconstituer des cartes isopaques de répartition des faciès et de reconstruire la paléogéographie des différentes unités stratigraphiques. Ces données permettent d'aborder la nature de la déformation et clarifient également le comportement des zones actives régionales élevées durant le Paléozoïque. La succession paléozoïque dans les bassins de Ghadamès et de Jefarah peut être divisée en cinq séquences de 1er ordre, délimitées par des discontinuités tectoniques majeurs avec une durée de séquence de 40 à 70 Ma. Dans ces cinq séquences, dix-huit séquences de 2ème ordre (10 à 40 Ma) ont été différenciées, décrivant les limites de séquence (SB), les surfaces d'inondation maximales (MFS) et les caractéristiques sédimentologiques. Vingt-huit puits ont été analysés afin d’identifier et d’évaluer les systèmes réservoirs paléozoïques dans les bassins Ghadamès et de Jefarah illustrant comment les propriétés réservoirs changent latéralement et verticalement dans le temps en fonction des environnements de dépôt. Deux logiciels ont été utilisés, le logiciel pétrophysique JLog pour l'analyse des propriétés réservoirs et PETREL pour la construction de modèles de corrélation stratigraphique. Les réservoirs dans la zone d'étude sont répartis sur une large gamme de réservoirs silicoclastiques s'étendant du Cambrien au Permien. Les hydrocarbures dans les bassins de Ghadamès et de Jefarah proviennent de deux roches mères principales, à savoir la Formation de Tanezuft du Silurien inférieure et la Formation d'Awaynat Wanin du Dévonien moyen-supérieur. Les neuf principaux réservoirs paléozoïques sont respectivement les formations de Hasawnah, de Hawaz et de Mamouniyat (Paléozoïque inférieure), d’Akakus, de Tadrart, d’Ouan Kaza et de Tahara (Paléozoïque moyen) et les Formations de M'rar et d’Asadjefar (Paléozoïque supérieur). Six sections transversales stratigraphiques dans la région ont été reconstruites pour illustrer les extensions verticales et latérales des réservoirs. L'ensemble de données acquises démontre que les propriétés réservoirs des séries paléozoïques sont influencées par les deux, les faciès et les environnements de dépôts. / The sedimentology and tectonics and their relationship of the Paleozoic series that fill the Ghadames basin and its northern extension consisting of the Jefarah basin in Libya and Tunisia was studied. These formations belong to the Gondwana cycle and are typically interpreted as being deposited in a cratonic basin truncated by the Hercynian unconformity. This study is based on wells. The stratigraphic correlation between the wells is based on the definition of second order cycles. This allowed to produce isopach maps of facies distributions and to reconstruct the paleogeography of the different stratigraphic units. These data allow to address the nature of the deformation and also clarifies the behavior of active high regional areas during the Palaeozoic. The Paleozoic succession in the Ghadames and Jefarah basins can be divided in to five first order sequences, bounded by major tectonic unconformities with sequence duration of 40 - 70 Ma. Within these five sequences eighteen second order sequences (10 - 40 Ma) were differentiated, describing Sequence Boundaries (SB), Maximum Flooding Surfaces (MFS) and sedimentological characteristics. Twenty six wells with its geological well reports and well logs have been used in the study area, i.e. the Ghadames and Jefarah basins (Libya) illustrate how reservoir properties changes laterally and vertically through time (from a proximal to a distal sitting). Two softwares were used, JLog (version 4) petrophysical software for reservoir property analysis and PETREL (Schlumberger software 2014 version) for constructing stratigraphic correlation models. The Paleozoic reservoirs in the study area are spread over a large range of siliciclastic reservoirs with the prospective section extending from Cambrian to Permian. Hydrocarbons within the Ghadames and Jefarah basins originated from two major source rocks: i.e. the Lower Silurian Tanezoft Formation and Middle-Upper Devonian Aouinat Ounine Formation. The nine main Paleozoic reservoirs are respectively the Hassaouna, Haouaz and Memouniat Formations (Lower Paleozoic), Acacus, Tadrart, Ouan Kaza and Tahara Formations (Middle Paleozoic) and M’rar and Asadjefar Formations (Upper Paleozoic). Six stratigraphic cross sections through the area have been reconstructed to illustrate the vertical and lateral reservoir extensions. The dataset demonstrates that the Paleozoic reservoir properties are influenced by both, depositional facies and position within the paleogeographical setting (from proximal to distal part).
215

Sismo-stratigraphie multi-échelles d'un bassin d'avant-arc : Le bassin de Marie-Galante, Petites Antilles

De Min, Lyvane 02 December 2014 (has links)
L’arc des Petites Antilles résulte de la lente subduction vers l'Ouest des plaques Nord et Sud-Américaines sous la plaque Caraïbes (2cm/an). A la latitude de l’archipel guadeloupéen et à ~150 km à l’Ouest du front de déformation, le bassin d'avant-arc de Marie-Galante forme un bassin perché, incliné vers la fosse et limité vers l’Est par un haut-fond, l’Eperon Karukéra. À cette latitude, le bassin de Marie-Galante domine le prisme d’accrétion de la Barbade et fait face à la ride de Tiburon qui balaye la zone du Nord au Sud depuis la fin du Miocène supérieur. Le remplissage sédimentaire du Bassin de Marie-Galante montre des déformations actives au moins depuis ~30 millions d’années. L’objectif du travail est de reconstituer l’évolution tectono-sédimentaire de ce bassin pour apporter de nouvelles contraintes sur la compréhension globale de la zone de subduction frontale des Petites Antilles. Ce travail s'appuie sur les données de bathymétrie multifaisceaux et de sismique réflexion multi-traces haute résolution acquises lors des campagnes du programme KaShallow. Cette base de données, complétée de profils sismiques plus basse résolution de campagnes antérieures, permet d’avoir une couverture pseudo 3D et à quatre échelles de résolution de l'ensemble du bassin. Un échantillonnage par ROV et carottage ciblé a fourni 40 prélèvements dans les principales unités sismiques. Les analyses pétrologiques et les datations biostratigraphiques autorisent des reconstitutions paléo-environnementales depuis le Paléogène supérieur jusqu’à Actuel. L’interprétation sismique multi-échelle montre un bassin sédimentaire atteignant ~4,5s temps double (~4500 à 5625 m) sur un substratum magmatique pré-structuré. Ce bassin est composé de 5 grands ensembles sédimentaires (E-1, E1, E2, E3 et E4) subdivisés en 13 unités limitées par 14 surfaces de discontinuités. L’organisation séquentielle des unités sismiques permet de mettre en évidence 10 séquences de dépôts de troisièmes ordres (S-1 à S9). Le calage biostratigraphique de l’ensemble des séquences permet de proposer une évolution tectono-sédimentaire du bassin de l’Éocène à l’Actuel. Ainsi, nous distinguons quatre systèmes de failles normales associées à trois phases d’extensions qui contrôlent l’évolution architecturale et sédimentaire du bassin. 1/ Un système N050±10°E hérité, actif dès le Paléogène supérieur, qui contrôle le basculement général du bassin vers le SSE. Il est responsable de la formation de l'escarpement de Désirade d’environ 4500 m de dénivelé. Cette première extension est interprétée comme résultant de la fragmentation de l'avant-arc en réponse à l'augmentation du rayon de courbure de la zone de subduction. 2/ Un système N130°-N150°E, structurant à l’échelle de l’Éperon Karukéra, qui contrôle la sédimentation dès le Miocène inférieur et marque une première phase d'extension transverse à l’arc. 3/ Un système N160°-N180°E qui segmente le Bassin de Marie-Galante en un sous-bassin à l'Ouest et l'Éperon Karukéra à l'Est. Cette seconde extension, globalement perpendiculaire à la marge, s'accompagne d’une subsidence et d'une inversion de la polarité du bassin en réponse à son basculement vers la fosse qui débute au cours du Miocène moyen et se poursuit actuellement à l'Est du bassin. Cette évolution à long terme de l'avant-arc, concomitante avec le recul de l'arc volcanique vers l’Ouest, est considérée comme résultant d’une érosion basale de la plaque supérieure. 4/ Un système N090±10°E plus tardif est localisé au centre du bassin et qui contrôle le développement de plates-formes carbonatées néritiques sur certaines têtes de blocs, comme par exemple à Marie-Galante. Cette dernière extension, parallèle à l’arc, se manifeste dans le bassin à partir du Pliocène inférieur. Elle se superpose au régime d'extension perpendiculaire à l'avant-arc et est interprétée comme l'accommodation du partitionnement de la déformation en réponse à l’obliquité croissante du front subduction vers le Nord. / The Lesser Antilles result of the slow westward subduction of the North and South American plate under the Caribbean plate (2 cm / year). At the latitude of the Guadeloupe archipelago and ~ 150 km to the west of the deformation front, the fore-arc basin of Marie-Galante forms a perched basin tilted to the pit and limited to the East by a shoal, the Spur Karukéra. At this latitude, Marie-Galante basin dominates the accretionary prism of Barbados and faces wrinkle Tiburon sweeping the area from North to South from the late Miocene. The sedimentary fill Basin Marie-Galante shows active deformation since at least ~ 30 million years. The aim of the work is to reconstruct the tectono-sedimentary evolution of the basin to provide new constraints on the overall understanding of the frontal subduction zone Lesser Antilles. This work relies on multibeam bathymetry data and high-resolution seismic reflection multi-traces acquired during campaigns KaShallow program. This database, supplemented by lower resolution of previous campaigns seismic profiles, provides a pseudo-3D coverage and four scales of resolution of the entire basin. ROV sampling and targeted core provided 40 samples in the main seismic units. Petrological analysis and biostratigraphic dating allow paleoenvironmental reconstructions from the upper Paleogene up Actuel. Seismic interpretation multiscale shows a sedimentary basin reaching ~ 4,5s double (~ 4500-5625 m) on a substrate pre-structured magma. This basin consists of 5 main sedimentary units (E-1, E1, E2, E3 and E4) divided into 13 units bounded by discontinuities 14 surfaces. The sequential organization of seismic units allows to highlight sequences 10 deposits of third order (S-1 to S9). The biostratigraphic calibration of all sequences able to offer a tectono-sedimentary evolution of the Eocene basin to Present. Thus, we distinguish four normal fault systems associated with three phases of extensions that control the architectural and sedimentary evolution of the basin. 1 / A system N050 ± 10 ° E inherited assets from the upper Paleogene, which controls the overall pelvic tilt towards the SSE. He is responsible for the formation of the escarpment Désirade about 4500 m elevation. The first extension is interpreted as resulting from the fragmentation of the fore-arc in response to the increase in the radius of curvature of subduction. 2 / A system N130 ° -N150 ° E, structuring across the Spur Karukéra, which controls sediment from the Miocene and marks the first phase of transverse extension arc. 3 / A system N160 ° E ° -N180 which segments Basin Marie-Galante in a sub-basin to the west and the Spur Karukéra in the East. This second extension, generally perpendicular to the margin, is accompanied by subsidence and reversing the polarity of the basin in response to his switch to the pit, beginning during the Middle Miocene and is ongoing in the East the basin. This long-term evolution of the forearc, concurrent with the decline in volcanic arc to the west, is considered as resulting from a basal erosion of the top plate. 4 / A system N090 ± 10 ° later E is located in the center of the basin and controlling the development of neritic carbonate platforms on certain blocks heads, such as Marie-Galante. This latest extension, parallel to the arc occurs in the basin from the lower Pliocene. It is superimposed on the expansion plan perpendicular to the fore-arc and is interpreted as the accommodation of the partitioning of deformation in response to the increasing obliquity front subduction north.
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Sequence stratigraphic characterisation of petroleum reservoirs in Block 11b/12b of the Southern Outeniqua Basin

Nfor, Nformi Emmanuel January 2011 (has links)
Magister Scientiae - MSc / The main purpose of this study was to identify and characterize the various sand prone depositional facies in the deepwater Southern Outeniqua Basin which generally tend to form during lowstand (marine regression) conditions producing progradational facies. It made use of sequence stratigraphy and turbidite facies models to predict the probable location of deepwater reservoirs in the undrilled Southern Outeniqua Basin using data from basin margin Pletmos Basin and the deepwater Southern Outeniqua Basin. Basin margin depositional packages were correlated in time and space with deepwater packages. It was an attempt at bridging the gap between process-related studies of sedimentary rocks and the more traditional economic geology f commercial deposits of petroleum using prevailing state-of-the-art in basin analysis. It enabled the most realistic reconstructions of genetic stratigraphy and offered the greatest application in exploration. Sequence stratigraphic analysis and interpretation of seismics, well logs, cores and biostratigraphic data was carried out providing a chronostratigraphic framework of the study area within which seismic facies analysis done. Nine (9) seismic lines that span the shallow/basin margin Pletmos basin into the undrilled deepwater Southern Outeniqua basin were analysed and interpreted and the relevant seismic geometries were captured. Four (4) turbidite depositional elements were identified from the seismic lines: channel, overbank deposits, haotic deposits and basin plain (basin floor fan) deposits. These were identified from the relevant seismic geometries (geometric attributes) observed on the 2D seismic lines. Thinning attributes, unconformity attributes and seismic facies attributes were observed from the seismic lines. This was preceded by basic structural analyses and interpretation of the seismic lines. according to the structural analysis and interpretation, deposition trended NW-SE and NNW-SSE as we go deepwater into the Southern Outeniqua basin. Well logs from six (6) of the interpreted wells indicated depositional channel fill as well as basin floor fans. This was identified in well Ga-V1 and Ga-S1 respectively. A bell and crescent shape gamma ray log signature was observed in well Ga-V1 indicating a fining up sequence as the channel was abandoned while an isolated massive mound-shape gamma ray log signature was observed in Ga-S1 indicating basin plain well-sorted sands. Core analyses and interpretation from two southern-most wells revealed three (3) facies which were derived based on Walker‘s 1978, turbidite facies. The observed facies were: sandstone, sand/shale and shale facies. Sequence stratigraphic characterisation of petroleum reservoirs in block 11b/12b of the Southern Outeniqua Basin. Cores of well Ga-V1 displayed fine-grained alternations of thin sandstone beds and shales belonging to the thin-bedded turbidite facies. This is typical of levees of the upper fan channel but could easily be confused with similar facies on the basin plain. According to Walker, 1978 such facies form under conditions of active fan progradation. Ga-S1 cores displayed not only classic turbidite facies where there was alternating sand and shale sections but showed thick uninterrupted sections of clean sands. This is typical of basin plain deposits. Only one well had biostratigraphic data though being very limited in content. This data revealed particular depth sections and stratigraphic sections as having medium to fast depositional rates. Such rates are characteristic of turbidite deposition from turbidity currents. This study as well as a complementary study by Carvajal et al., 2009 revealed that the Southern Outeniqua basin is a sand-prone basin with many progradational sequences in which tectonics and sediment supply rate have been significant factors (amongst others such as sea level change) in the formation of these deepwater sequences. In conclusion, the Southern Outeniqua basin was hereby seen as having a viable and unexplored petroleum system existing in this sand prone untested world class. / South Africa
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Caractérisation et facteurs de contrôle des distributions minéralogiques du Bassin Piggyback de Graus-Tremp-Ainsa (Espagne), à l’Eocène Inférieur. / Mineralogical distributions and associate controlling factors in the Graus-Tremp-Ainsa piggyback Basin (Spain) during the Early Eocene.

Chanvry, Emmanuelle 16 December 2016 (has links)
Cette thèse propose une méthodologie pour caractériser et intégrer les distributions minéralogiques des dépôts de l’Eocène Inférieur du Bassin de Graus-Tremp-Ainsa dans un cadre séquentiel reconstruit à haute résolution. Le couplage des approches stratigraphiques et géochimiques/minéralogiques permet d’évaluer la part des forçages tectoniques, climatiques, eustatiques et diagénétiques sur l’enregistrement sédimentaire et minéralogique du bassin. La caractérisation de la minéralogie repose sur un calcul automatisé utilisant la géochimie multi-élémentaire et calibré ponctuellement par les outils d’analyse minéralogique conventionnels (pétrographie, DRX, Qemscan, microsonde). Elle a l’avantage de permettre de traiter les évolutions minéralogiques à l’échelle du bassin et sur l’ensemble des lithologies rencontrées. Après avoir évalué les effets de la diagenèse, du tri hydrodynamique et reconstitué la composition minéralogique primaire des sédiments, nous caractérisons les différentes sources.Nous précisons l’évolution de la tectonique (avec un pas de temps de l’ordre du million d’années) et ses effets sur l’architecture sédimentaire et la minéralogie des dépôts. Ceux-ci montrent un contrôle spatial de la diagenèse et des changements spatio-temporels des sources, liés à une compétition entre la tectonique intrabassinale (activité des chevauchements locaux) et régionale (surrection de l’orogène et subsidence flexurale). Nous montrons également que l’impact de la tectonique est modulé par des anomalies climatiques ponctuelles de l’ordre de la centaine de milliers d’années (PETM, ELMO, X-Event), que nous avons reconnues par un changement marqué des environnements de dépôt et des cortèges argileux.Deux grands épisodes régionaux caractérisent l’évolution du Bassin piggyback de Graus-Tremp-Ainsa. Le stade précoce, d’âge Ilerdien-Cuisien Inférieur, est marqué par le passage d’une rampe carbonatée mixte à des systèmes deltaïques alimentés depuis l’orogène pyrénéen par des contributions plutoniques. Cet ensemble passe ensuite à un vaste système fluvio-deltaïque au Cuisien Inférieur / Moyen, montrant l’apport de lithiques carbonatés et silicoclastiques qui coïncide avec l’émergence des nappes sédimentaires. La fin de cet épisode est marquée par la propagation du chevauchement du Montsec et de ses rampes latérales, provoquant un partitionnement du bassin, induisant la surrection du Bassin de Graus-Tremp et une forte subsidence du Bassin d’Ainsa. Ce contraste de subsidence est souligné par un partitionnement de la diagenèse, avec une kaolinisation des formations supérieures du Bassin de Graus-Tremp, liée à la percolation d’eaux météoriques, et, dans le Bassin d’Ainsa, une albitisation des grès couplée à une illitisation des smectites dans les lutites, liée à une diagenèse d’enfouissement plus marquée. / We develop here a methodology to integrate the mineralogical record into a high resolution sequence stratigraphic framework realized in the Early Eocene Graus-Tremp-Ainsa Basin. Coupling stratigraphic with geochemical and mineralogical approaches allows us to unravel the effects of tectonics, climate, eustasy and diagenesis on basin architecture and mineralogy. An automated computed mineralogy is derived from whole-rock geochemical data, and calibrated against direct mineral quantifications (petrography, DRX, Qemscan, microprobe). It provides a basinscale view of mineral distribution, irrespective of the lithology. Diagenetic overprint and hydrodynamic sorting effects are evaluated first, then primary mineral distributions are reconstructed and ascribed to different types of sediment sources.We show that, at the million-year timescale, tectonics shape the architecture and the mineralogy of the deposits. Spatially distributed diagenesis and temporal and spatial changes in sediment sources reflect the competing effects of intrabasinal tectonics (local thrust displacements) versus basinscale flexural subsidence linked to the orogen uplift and loading. Tectonically-driven changes are also sensitive to higher frequency (100 ky) anomalic climatic events (PETM, ELMO, X-EVENT) leaving a mineralogical signal in clay fractions and environment deposits succession.The basinscale evolution displays two contrasting stages. During the Ilerdian to the lower Cuisian, a mixed carbonate ramp evolves to a set of deltaic fans of Northern (Pyrenean orogen) provenance delivering plutonic-dominated materials. Then, during the lower/mid Cuisian, they are overprinted by a large fluvial and deltaic system bringing recycled carbonates and siliciclastics sourced in the emerging eastern to southern sedimentary thrust sheets. Later on, the propagation of the Montsec thrust and its lateral ramp decouples the uplifted Graus-Tremp basin from the strongly subsiding Ainsa basin. These different subsidizing schemes are underlined diagenetic overprints diverge, with an extensive kaolinisation of the uppermost units in the Graus-Tremp Basin driven by meteoric fluid circulations, and a severe albitisation of sandstones in the Ainsa basin, coupled with the illitisation of smectites in the lutites and caused by deep basinal fluids.
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Near-Salt Stratal Geometries and Implications for the Evolution of the Onion Creek Diapir Moab, UT

Cook, Ethan L. 01 April 2017 (has links)
The Onion Creek Diapir is one of many salt domes proximal to the Uncompahgre thrust front of the ancestral rockies in the Paradox Basin. It is comprised of Paradox Formation evaporites and large blocks of Honaker Trail Formation carbonates that were deformed by loading of Permian Cutler Formation progradational alluvial to fluvial fans. The history of salt movement in the Onion Creek Diapir is recorded in the near-salt strata. Large salt bodies and their adjacent mini-basins evolve conforming to a complex relationship between salt withdrawal, creating localized accommodation, and sediment deposition. Migrating mini-basin depo-centers, thinned and folded strata, and spatial facies trends reveal the relative rates of diapirism and sedimentation. The study area outcrop, north of the diapir, is divided by significant stratigraphic horizons that help define depositional periods. Six measured sections in the study area reveal higher preservation rates of fine grained floodplain deposits, typically destroyed in alluvial environments, than at locations correlating to stratigraphic levels high in the outcrop suggesting a low accommodation environment evolving into higher accommodation where stacked channel complexes are preserved. Preserved slump folding at the base of the outcrop reveals that although some salt emergence occurred in the earliest depositional period it was not significant enough to preclude sediment deposition or to divert the Cutler fluvial network and destroy floodplain facies. A 3-D digital outcrop, modeled from photogrammetric data, illustrates the development of localized accommodation, attracting fluvial channel in a near-salt, tight axial syncline during the later depositional period. These evidences suggest a greater emergence of the diapir and likely diversion of the Cutler channel complexes.
219

Architektury, stratigrafie a sedimentární režim pískovcových těles spodního a středního turonu v sz. části české křídové pánve / Depositional architectures, stratigraphy, and depositional regime of Lower-Middle Turonian sandstone bodies, northwestern part of the Bohemian Cretaceous Basin

Skopcová, Monika January 2010 (has links)
Sandstone bodies of the Lower and Middle Turonian well exposed in the northwestern part of the Bohemian Cretaceous Basin represent deposits of the coarse-grained deltas. Aim of this paper is to interpret the architectures, stratigraphy and depositional regime of these bodies. The main architectural elements are clinoforms which show intermediate dip 4ř to 5ř of the delta slope and the direction of the progradation of the delta to the west-southwest. Correlation of the lithological profiles with the well - log data provided the stratigraphic classification of the outcrops in the studied area mostly to the genetic sequence TUR2. Correlations in one of the two stratigraphic cross - sections revealed the existence of the second delta body prograding into the basin from Most - Teplice Palaeohigh during TUR1. Detailed study of the sedimentary structures in the outcrops show high degree of reworking of foresets by tidal generated current. Two main directions of the paleocurrents results from the analysis - dominant current to the NW and subordinate current to the SE - SSE.
220

Architektury, stratigrafie a sedimentární režim pískovcových těles svrchního turonu v sz. části české křídové pánve / Depositional architectures, stratigraphy, and depositional regime of Upper Turonian sandstone bodies, northwestern part of the Bohemian Cretaceous Basin

Vacková, Lenka January 2010 (has links)
This diploma thesis presents a synthesis of fieldwork and well-log data of the Upper- Turonian sandstone bodies in the northwestern part of the Bohemian Cretaceous Basin. There was no previous research based on method of the sequence stratigraphy and correlation well-logs. I made 13 measured sedimentological cross-sections that were correlated to stratigraphical cross section along depositional dip and strike. Structures of the Upper Turonian sandstones (genetic sequences TUR 5 - 7) are dominated by trough cross bedding that migrate on a slightly inclined delta slope (1 - 5ř). The main direction of paleocurrents is towards SE or E. The analysis of thicknesses of parasequences (for TUR 4 - TUR 7) gives trend of thinning parasequences through time. Increasing content of the potassium is evident within sequences TUR 4 to TUR 7. It is independent on the grain-size, but indicates rapid transport from the source area.

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