Dissertações em Geofísica (Mestrado) - CPGF/IG

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4993

O Mestrado Acadêmico pertente a o Programa de Pós-Graduação em Geofísica (CPGF) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA).

Navegar

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Caracterização de hidratos de gás a partir de dados geofísicos da região da Bacia Tumbes-Progresso (Peru)
(Universidade Federal do Pará, 2014-02-25) TEJADA SOTO, Zoraida Roxana; GOMES, Ellen de Nazaré Souza; http://lattes.cnpq.br/1134403454849660
Gas hydrate is known as a potential source of hydrocarbon energy. However, the detection of exploitation of this resource is still inexpressive. This is due to two factors: the diculty of detecting pro table areas of gas hydrates and due to the high risk involved in exploration. In this study, an analysis is presented to detect possible areas of gas hydrate ocurrence in a region of Tumbes-Progresso Basin, using geophysical data: magnetic, gravity, seismic and borehole (well data). It presents three approaches to demarcate the possible zones of hydrate: First, magnetic and gravity anomalies analyzed with respect to the geology and the study area that was chosen. It was subsequently made a seismic imaging the region of interest and the gas hydrates has been identied based on the presence identication of BSR (Bottom Simulating Refletor), This reflector correspond to a limit between gas hydrate and free gas zone. BSR potential was applied the AVO analysis (Amplitude Versus Oset). Finally, in the third approach, well data are evaluated, calculating the porosity and saturation of the rock in the gas hydrate stability zone. According to the analysis presented, It was veried the occurrence of gas hydrate in the study area.
Acesso aberto (Open Access)
Inversão 1D e 2D de dados do método eletromagnético a multi-frequência - EMMF
(Universidade Federal do Pará, 2014-11-14) PIEDADE, Anderson Almeida da; RÉGIS, Cícero Roberto Teixeira; http://lattes.cnpq.br/7340569532034401
In this work is presented the rst study of data inversion from Electromagnetic Multi- Frequency Method (EMMF). In its rst part is made a presentation of the mathematical techniques used for inversion of these data. It will be shown the Gauss-Newton technique with modied Marquardt algorithm and a description of two regularization methods used in the inversion, which are Global Smoothness method (GS) and Total Variation method (TV). In the second part, they are applied to 1D inversion of EMMF synthetic data as well as are applied to real data, that were acquired in the Esprito Santo Basin, southeastern Brazil. In the third and last part, it presented the 2D inversion of EMMF synthetic data, with models, which like the 1D inversion, involving conductive and resistive targets. Results of this study show that the inversion of data from conductive targets was able to recover the resistivity structures more consistently with the true resistivity model than in the case of resistive targets. This may be due to the fact that the purely inductive radial magnetic component is naturally more strongly in uenced by conductive than by resistive regions in the geoelectrical medium.
Acesso aberto (Open Access)
NIP-tomografia usando método CRS e dados sísmicos marinhos
(Universidade Federal do Pará, 2013) AFONSO, João Batista Rodrigues; LEITE, Lourenildo Williame Barbosa; http://lattes.cnpq.br/8588738536047617
This work consisted on the application of techniques for processing, inversion and imaging of the Marmousoft synthetic data, and of the Jequitinhonha real data obtained on the eastern Atlantic continental shelf of the State of Bahia. The convencional NMO and CRS stack methods, and NIP-tomographic inversion were applied to the mentioned data. The NMO stack served to produce RMS and interval velocity distribution maps on the semblance domain. The CRS stack of both data we used for picking of re ection events to obtain the wave eld parameters that served to constrain the model as input for the NIP-tomographic inversion. The inversion characterizes as resulting in a smooth velocity model. Kirchhoff depth migration was used for verifying the obtained velocity models. We critically analyzed the applied techniques, and compared the CRS and the NMO stacks. The evolution of the visual quality of the obtained CRS and NMO sections were analyzed as measured by event continuity trace-by-trace and the signal/noise ratio. The di erences and improvements on the velocity model obtained by NIP-tomographic were also analyzed. The Kirchhoff prestack depth migration was applied aiming at geological interpretations, and to point out for better conditions of processing and imaging.
Acesso aberto (Open Access)
Paleomagnetismo de rochas vulcânicas do Nordeste do Brasil
(Universidade Federal do Pará, 1986-01-24) SOUZA, Orlando Tadeu Lima de; GUERREIRO, Sonia Dias Cavalcanti; http://lattes.cnpq.br/1958830414070291
Acesso aberto (Open Access)
Separação regional-residual em magnetometria através de camadas equivalentes
(Universidade Federal do Pará, 1987-12-28) COSTA, Jessé Carvalho; SILVA, João Batista Corrêa da; http://lattes.cnpq.br/1870725463184491

Navegar

Navegando Dissertações em Geofísica (Mestrado) - CPGF/IG por CNPq "CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS"