3ERL - Congress and other Meeting Presentations/ Apresentações em Congressos e em Outras Reuniões
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- Recent Developments in Logging Techniques and Interpretation in IndonesiaPublication . Pirard, Yves; Prins, Wliliam J.; Cramez, Carlos
- Stratigraphic Cycles and Major Marine Source RocksPublication . Duval, Bernard C.; Cramez, Carlos; Vail, Peter R.
- Crítica do Método Indutivo na Pesquisa PetrolíferaPublication . Cramez, CarlosAs principais mensagens passadas nesta monografia são que a Ciência e, em particular, a pesquisa petrolífera (i) começa sempre um por problema e não por observações, e (ii) a Teoria precede sempre a observação. Quer isto dizer que as teorias não derivam de uma acumulação de observações sem ideias apriorísticas. Na realidade, em Portugal, os professores de Geologia, que ainda seguem o método proposto por Bacon (indução), quando vão para o campo com os alunos, têm grandes problemas quando dizem aos mesmos para observar. Com efeito, a resposta imediata dos alunos é: Mas oh senhor professor, o que é que nós devemos observar? É, em geral, a partir deste momento, que certos professores descobrem que os estudos geológicos começam sempre por problemas para resolução dos quais se avançam, em primeiro lugar, hipóteses, só depois se passando a colher dados de observação que permitam criticar as hipóteses avançadas e, assim, escolher a menos falível. Além disso, as observações a efectuar com vista a corroborar ou a rejeitar as hipóteses avançadas, têm obrigatoriamente incidir sobre temas previamente já estudados, pois a afirmação de que “a Teoria precede a prática” quer, afinal, dizer que no decurso de uma sessão de observação ninguém é capaz de ver aquilo que ainda desconhece.
- Prerequisites, general criteria and primary studies required in the CoalbedMethane prospecting and exploring: A reviewPublication . Lemos de Sousa, M. J.; Pinheiro, H. J.; Rodrigues, CristinaThe main objectives of this paper are: (i) to review and summarize current concepts of Coalbed Methane (CBM) genesis and storage, (ii) to highlight and present the principal procedures and methodologies concerned with prospecting/exploring of CBM leading to a sequence of basic criteria to be followed at an early stage and, subsequently, during research and exploration, and (iii) to present a list of the most important analytical requirements during the investigations.
- The role of coal “cleat system” in Coalbed Methane Prospecting/Exploring: A new approachPublication . Rodrigues, Cristina; Laiginhas, C.; Fernandes, M.; Lemos de Sousa, M. J.The Coalbed Methane (CBM) generated by coal is located in coal pores and the drainage of the coalbed gas to the production well is made through the so-called "cleat system", i.e., the natural fracture network of coal. This justifies the classic method of CBM production by providing fracture-stimulation with fluids under pressure to open coal natural fractures. However, natural fracturing system of any coal is very complex, depending on coalification process and local and regional tectonics. Additionally, the cleat network cannot be inferred using conventional regional micro-tectonics studies. Therefore, what really matters is to know, in each case, the spatial orientation of the different classes of fracturing, ordered by connectivity frequencies, to make possible an orientated injection of fluids to open the cleat permitting higher amounts of gas release/drainage. In fact, the cleat family of highest connectivity frequency is the one that define the gas circulation network to the producing well, and consequently the most favorable one to be opened by fluids injected in the correct direction. The current investigation refers to a new and innovative proposal to develop a method for determining cleat family orientation in the space, ordered by cleat connectivity frequency. This new semi-automatic method is based in the study of "cleat characteristics" by image analysis in orientated core samples of boreholes for CBM prospection/exploration. The information from image analysis is studied by statistical CCT ("coal-core tectonics") methodology and subsequently combined with Geographic Information System, thus referring to location of the real case under study.
- Characterization of Coal Maceral Groups by Micro-Raman SpectroscopyPublication . Valentim, B.; Guedes, A.; Prieto, A. C.; Lemos de Sousa, M. J.Uma caracterização rápida e não-destrutiva da organização estrutural do material carbonoso pode ser conseguida através da espectroscopia micro-Raman, uma vez que podem ser obtidos espectros de áreas micrométricas. Uma aplicação óbvia desta técnica é a caracterização pontual de macerais do carvão. As análises de espectroscopia micro-Raman efectuadas em diferentes grupos macerais do mesmo carvão revelam, para além da presença dos habituais picos aos 1580 cm-1 e 1350 cm-1 no espectro de primeira ordem, dois picos de fraca intensidade: um próximo dos 1170 cm-1 nos macerais do grupo da inertinite e outro aos 1470 cm-1 nos macerais de vitrinite e liptinite. Os diferentes grupos macerais apresentam várias diferenças no espectro de primeira ordem, um estreitamento do pico 1580 cm-1 e seu deslocamento para números de onda mais elevados da vitrinite para a liptinite e inertinite; um deslocamento do pico 1350 cm-1 para números de onda mais baixos da vitrinite para a liptinite e para a inertinite, conjuntamente com o seu estreitamento na inertinite e um ligeiro aumento da razão entre a intensidade dos picos 1350/1580 da vitrinite para a inertinite e para a liptinite. A fast and non-destructive characterization of the local state of carbonaceous material may be achieved with a micro-Raman spectrometer, since spectra from micrometric areas can be recorded. Therefore, this technique can obviously be applied for characterization of coal macerals. Raman spectral analysis performed on different coal maceral groups of the same coal reveals not only the presence of the usual peaks at 1580 cm-1 and 1350 cm-1on the first-order Raman spectrum, but also the presence of two additional weaker peaks, one around 1170 cm-1 in inertinite and another around 1470 cm-1 appearing in vitrinite and liptinite. Differences of the first-order spectrum of the different macerals include a shift of the 1580 cm-1 peak towards higher wavenumbers accompanied by its narrowing from vitrinite to liptinite and inertinite; a shift of the 1350 cm-1 peak towards lower wavenumber from vitrinite to liptinite and to inertinite together with a small narrowing in the inertinite and a slight increase in the 1350/1580 peak intensity ratio from vitrinite to inertinite and to liptinite.
- Hydrocarbon Problems & Nature PrinciplesPublication . Cramez, Carlos; Laherrere, J.The understanding of Energy problems, Peak Oil Production Hydrocarbon Remaining Reserves, etc., is based on Nature Principles, which allow the interpretation of Hydrocarbon Data, and so, advance several petroleum conjectures.
- Atlantic Ocean OpeningPublication . Cramez, CarlosA new model for the opening of the Atlantic is proposed. Subaerial lava flows were emplaced since the breakup of the lithosphere till subaerial spreading centres became immersed. Twined evaporitic basins, with brines enriched by spilitisation of the basalt of the lava flows, developed in each side of the mid-oceanic ridge. The Iberia offshore, and probably also the Newfoundland offshore, had particular geologic histories. In northern area, the breakup took place in a deepwater environment, so SDRs were not developed. In Iberia offshore, an incipient Benioff subduction zone could be the chiefly responsible for the compressional tectonic regime that took place since Upper Miocene (?).
- Contractional Cornucopia on Offshore AngolaPublication . Cramez, Carlos; Jackson, M. P. A.; Sikkema, W.; Fraenkl, R.Three main contractional tectonic regimes are recognized: (1) Late Cretaceous gravity spreading, (2) Mid-Tertiary uplift, and (3) Neogene transpression. Tilting of the young continental margin created the first tectonic regime, the ultimate cause of this was thermal subsidence after continental breakup. The second regime was the direct cause of the uplift of the Angolan coast, mostly in the Oligo-Miocene but continuing into the Plio- Pleistocene, while the late tectonic regime was probably the differential movement of reactivated crustal blocks, whose slip directions depended on their orientation.
- Can the South Atlantic Opening Model be Applied to the India Margins?Publication . Cramez, Carlos; Talwani, Manik; Jackson, M. P. A.The presence of SDRs (seawrd dipping reflectors) on the regional lines around the Indian continent strongly suggest the breakup of the lithosphere and the onset of the sea-floor spreading were similar to those proposed and described for the South Atlantic, which, in fact, is quite similar to the opening of the North Atlantic.