3ERL - Courses and Lectures/ Cursos e Lições
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- Atlantic-Type Divergent MarginsPublication . Cramez, Carlos
- Atlas of typical deep water seismic linesPublication . Cramez, CarlosIn this atlas, commented tentative geological interpretations, mainly, of Canvas autotraces of worldwide typical deep water seismic lines are proposed. The Bally and Snelson’s (1980) sedimentary basin classification was adopted. Remind: (i) Rift-Type basins, Cratonic basins and Atlantic-type Divergent Margins are sedimentary basins not associated with the formation of Megasutures ; (ii) Episutural and Perisutural basins are associated with the formation of Megasutures ; (iii) Forearcs, foredeeps and Chinese-type basins are perisutural bsins, the firsts associated with B-type subduction zones, the second with A-type subduction zones and the thirds with tilted blocks, normally developed by megasutures but, where the subduction zone A is not evident ; (iv) Backarcs and non Atlantic-type divergent margins are episutural basins associated with B-type subduction zones, the firsts without oceanization behind the volcanic arc, the seconds with oceanization ; (v) Panonnian-type and Mediterranean-type basins are episutural basins associated with A-Type subduction zones, the firsts without oceanization and the seconds when there is breakup and oceanization of the underlying fold belt ; (vi) The Great Basin and Californian-type basins are episutural associated with significant strike slip faulting ; (vii) Fold belts are developed inside the megasutures in connection with A or B-type subduction zones.
- Basic principles in tectonicsPublication . Cramez, Carlos; Letouzey, Jean
- Basic principles of scientific seismic interpretationPublication . Cramez, Carlos
- Bassins sédimentaires & systèmes pétroliersPublication . Cramez, Carlos
- Campos Gigantes de Finales de los 80 Asociados con Subducción Tipo "A" en SuraméricaPublication . Cramez, Carlos
- Challenges to carbon capture and storage: a portuguese case-studyPublication . Oliveira, GiselaThis lecture addresses the main challenges associated to the design of a CCS project and its subsequent installation and operation focusing on the Portuguese mainland as a case study. The work targets national sedimentary basins and based on the existing literature screens these basins to found suitable geologic formation for the permanent and safe CO2 geological storage. Several geological formations were identified as potential CO2 reservoirs most of them situated offshore. The assessment of risks associated to the geological storage of CO2 are considered based on a qualitative methodology.
- Estratigrafia sequencial: definições e ilustrações dos termos e conceitosPublication . Cramez, Carlos; Lemos de Sousa, M. J.Os glossários, thesaurus, ou léxicos e os vocabulários são, geralmente, elaborados tendo em vistas dois objectivos diferentes, mas complementares na práctica. Eles são concebidos quer para aparecerem como um apêndice no fim de um trabalho de fundo ou de um curso temático, dando a significação e outros detalhes sobre as palavras chave e/ou expressões utilizadas nos textos de base, quer destinados a ser publicados, digamos de maneira autónoma. O trabalho aqui apresentado corresponde, simplesmente, a uma compilação de definições e conceitos dispersas nas mais variadas publicações sobre a Estratigrafia Sequencial. Ele é destinado, principalmente, a servir os jovens geocientistas que seguiram os nossos cursos e ateliers, uma vez que todos os termos definidos foram e são utilizados nessas classes. No vocabulário, para cada termo, apresenta-se: (i) uma definição sucinta (com uma tradução em inglês, francês, espanhol, alemão, chinês, russo e italiano que, mais tarde, será actualizada, particularmente, a tradução em alemão) ; (ii) uma tentativa de interpretação de uma linha sísmica, um esquema ou uma fotografia ilustrando o seu significado e (iii) um comentário, por vezes com notas, esclarecendo determinados pontos relacionados com a ilustração do termo.
- Foredeep & Foldbelt BasinsPublication . Cramez, CarlosOn these notes, in a succinct and eclectic manner, are highlight the main à priori geological knowledge that a petroleum geologist must have to make fruitful geological observations in foredeep basins either in the field or seismic data or sub-surface data. Colville basin and the stratigraphic column of Brooks (foredeep basin in Alaskan onshore) are taken as characteristic examples of these types of sedimentary basins. The main tectonic-sedimentary units, the different discordances, the flexural subsidence, and the deformations induced either by the loading of the sedimentary prism or by thermal contraction, are described. In the same way, the dimensions, evolution and burial history of this type of basins are reviewed. Their knowledge is a sina qua non condition for the recognition and evaluation of their potential petroleum systems.
- Frequent errors in the geological interpretation of seismic linesPublication . Cramez, Carlos1) All geological observation are theory laden. 2) Geoscientists forget to use the geological context on tentative geological interpretations of the seismic lines, locating them in relation to geographic or administrative basins and not to sedimentary basins defined in a specific basin classification. 3) Using the classification of Bally & Snelson (1980), geoscientists know, in advance, what they must to look for on seismic lines, because it gives the geological context of the main geological events and critical hydrocarbon parameters. 4) An easy refutation test of a geological interpretation (cross-section or seismic line) is to look at the dip of the proposed fault planes, which, at scale 1:1, must dip according to the Anderson's theory of faulting. 5) Every time a geoscientist shows you a delta slope on a seismic line, there is a high probability that he is showing a continental slope. The large majority of delta slopes are under seismic resolution. 6) A delta height, rarely, exceeds 100 m. A delta slope height, rarely, exceeds, 250 m. The length of a delta slope can reach more than 100 km. In appropriated geological settings, delta slopes are just visible on seismic lines with an important vertical exaggeration. 7) Geoscientists forget, often, that a seismic line looks like a geological cross section, but its vertical scale is in time (t.w.t.) and not in meters. A lot of corrections must be take into account. 8) The geometrical relationships between seismic reflectors and seismic surfaces defined, by reflections terminations, have a geological meaning just in its original depositional position. 9) At the scale of a sedimentary basin, all chronostratigraphic depositional surfaces have, a geometry, more or less, sigmoidal, with subhorizontal sectors confined by seaward dipping sectors. 10) In sequential stratigraphy, an unconformity is an erosional surface induced by a significant relative sea level fall. In other branches of the Geology an unconformity can have other meanings. 11) Some geoscientists continue to forget in their models the long periods of calm where nothing happens. In most stratigraphic sections, the duration of the hiatus is, generally, greater than the total duration of real deposition of the preserved sediments. 12) Few geoscientists know the difference between absolute and relative sea level. In addition, generally, they do not have any idea how sea level changes are measured, but they use them to explain the cyclicity of sedimentary deposits. 13) "When the sea level rise, we get a transgression and when the sea level falls we have a regression" [sic] is a false statement. A sedimentary transgression does not exist in Geology. A set of increasingly smaller sedimentary regressions can be, eventually, interpreted as the consequence of marine ingressions (transgressions). 14) When interpreting, in geological terms, a seismic line, do not forget, that the amount of sediments must be kept, more or less, constant. 15) Seismic lines are bad copies of geological reality. Tentative geological interpretations of seismic lines are far from showing the geological reality: they have a time vertical scale and a lot of lateral velocity changes inducing a lot of pitfalls. 16) Potential marine source-rock, can be localize, in the field or on seismic lines. They lie along the interfaces between retrogradational and progradational intervals.17) An angular unconformity is just a tectonically enhanced cryptic unconformity, i.e., an erosional surfaces induced by a relative sea level fall. Hydrocarbons traps associated with angular unconformities are independent of the mapping of the unconformity. They are defined by the maps of the reservoir-rock, sealing-rock and hydrocarbon migration paths. 18) Structural traps are developed in shortened geological structures. They have their own closure (four way dips). Traps against faults do not exist. Few geoscientists know what is a morphological trap by juxtaposition. Hydrodynamic traps in the majority of the cases are, totally, forgotten. 19) The first step in a tentative geological interpretations of a seismic line is to decide if the sediments are shortened or lengthened. A bad decision leads, necessarily, to a wrong tentative interpretation, because the geoscientist will be looking for geological events that are not present on the seismic line. 20) Lithological predictions can just be made on tentative geological interpretations of seismic lines made at the highest hierarchical level, i.e., at the sequence-paracycle level, in which the different depositional systems tracts and depositional systems are recognized.
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