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).
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Item Acesso aberto (Open Access) Modelo para correlação de litologias complexas utilizando os perfis de espectrometria de raios gama naturais(Universidade Federal do Pará, 1996-08-21) PANTUZZO, Fernando Luiz; SILVA, Jadir da Conceição da; http://lattes.cnpq.br/9855982521499301Item Acesso aberto (Open Access) Uma nova abordagem na interpretação de anomalias gravimétricas em bacias sedimentares - exemplo da Bacia do Recôncavo, Bahia, Brasil(Universidade Federal do Pará, 1990-10-12) MENEZES, Paulo de Tarso Luiz; SILVA, João Batista Corrêa da; http://lattes.cnpq.br/1870725463184491Item Acesso aberto (Open Access) Modelo interpretativo para os levantamentos gravimétricos de Poço da Bacia de SE/AL(Universidade Federal do Pará, 1991-09-27) MORAES, Fernando Sergio de; O'BRIEN, Douglas PatrickItem Acesso aberto (Open Access) Otimização computacional da técnica de elementos finitos para o modelamento geofísico eletromagnético(Universidade Federal do Pará, 1991-11-25) BATISTA, Lurimar Smera; PORSANI, Milton José; http://lattes.cnpq.br/1428637808064409Item Acesso aberto (Open Access) Regressão múltipla de perfilagem geofísica aplicada à estimativa de teor mineral(Universidade Federal do Pará, 1989-10-02) SANTOS, Deusivaldo Aguiar; SAUCK, William August; http://lattes.cnpq.br/6655455534234531Item Acesso aberto (Open Access) Propagação de ondas em meios elásticos: uma solução via transformada de hankel e o método dos elementos finitos(Universidade Federal do Pará, 1988-02-03) GEMAQUE, Luiz Heitor da Paz; SCHIEL, Klaus Rainer; http://lattes.cnpq.br/1748862841375705Item 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/1870725463184491Item Acesso aberto (Open Access) Modelamento sísmico analógico(Universidade Federal do Pará, 1986-09-19) MONTEIRO, Paulo Afonso da Costa; SCHIEL, Klaus Rainer; http://lattes.cnpq.br/1748862841375705Item 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/1958830414070291Item Acesso aberto (Open Access) Um sistema de aquisição de dados magnetotelúricos usando um minicomputador(Universidade Federal do Pará, 1986-09-19) MARTÍNEZ, Maurício Miguel Martínez; BISCHOFF, Jürgen H.Item Acesso aberto (Open Access) Propriedades elétricas de rochas da bacia sedimentar Sergipe-Alagoas(Universidade Federal do Pará, 1986-09-16) SILVA, Aldenor Santos da; SAUCK, William August; http://lattes.cnpq.br/6655455534234531Item Acesso aberto (Open Access) Resposta Hlem de um cilindro horizontal envolto por um halo condutor obtido por modelamento analógico(Universidade Federal do Pará, 1983-12-22) CABALLERO, Alberto; VERMA, Om Prakash; http://lattes.cnpq.br/2723609019309173Item Acesso aberto (Open Access) Tratamento quantitativo de anomalia de potencial espontâneo(Universidade Federal do Pará, 1976-10) GUERREIRO, Sonia Dias Cavalcanti; LOURENÇO, José SeixasItem Acesso aberto (Open Access) Paleocanais: uma opção para a prospecção de água subterrânea rasa na Ilha de Marajó(Universidade Federal do Pará, 1981-09-18) PORSANI, Milton José; RIJO, Luiz; http://lattes.cnpq.br/3148365912720676Item Acesso aberto (Open Access) Relaxações dielétricas do sistema carvão-pirita(Universidade Federal do Pará, 1978-07) PAIVA, José Airton Cavalcante de; ALVAREZ BEJAR, RománItem Acesso aberto (Open Access) Cálculo da porosidade: identificação do argilomineral(Universidade Federal do Pará, 2017-04-20) ALMEIDA, Thales Luiz Pinheiro de; ANDRADE, André José Neves; http://lattes.cnpq.br/8388930487104926In the daily practice of Formation Evaluation it is common the adoption of simplifying hypotheses or premises about the physical properties of the reservoir rock constituent materials to allow the porosity calculation. The knowledge of the physical properties of the clay in the reservoir rock is fundamental for porosity calculation. In this work it is argued that the physical properties of the clay mineral in the reservoir rock are different from the mean physical properties of the nearby shale layers. Geologically, the clay is one of the constituent materials of shale rock and to admit that the physical properties of the shale are equal to the physical properties of the clay in the reservoir rock means to disregard all the other constituents and to assume a sedimentary continuity that due to numerous postpositional processes may not occur. In this work, we apply the angular competitive neural network to the Density- Neutron Plot to show that if a reservoir rock and a shale present in the basin have the same clay, they have the same angular pattern. This methodology is presented with synthetic data and evaluated with actual well logs and core analysis from borehole drilled in the Namorado’s field, in the Campos Basin, Brazil.Item Acesso aberto (Open Access) Aproximações não-hiperbólicas do tempo de trânsito utilizando aproximantes de Padé(Universidade Federal do Pará, 2017-07-03) NEVES, Rodolfo André Cardoso; CRUZ, João Carlos Ribeiro; http://lattes.cnpq.br/8498743497664023Traveltime approximation is a fundamental tool of the stack and migration steps in seismic data processing. To increase the accuracy of these approximations, we propose new traveltime approximations based on Padé approximants, to CMP and CRS gathers. Hyperbolic approximations such as normal moveout (NMO) and comom reflection surface (CRS) are taylor series approximations of second order of the reflection traveltime. Padé approximants appear as an alternative to Taylor series, because they converge quickly to the desired function, and they have a major radius of convergence improving approximations acuracy. They can be obtained through the proper Taylor serie of the approximated function. This new approximation is obtained from the [2/2] Padé approximation of the generalized moveout equation; and from [2/2] Padé approximation of the Taylor series expansions of fourth order of the CRS surface. The acuracy of Padé approximation is superior when compared with other convencional approximations: normal moveout, shifted hyperbola and Transversal isotropic medium with vertical symetry axis (VTI). CMP gather Padé approximations depend just only one more parameter than normal moveout approximation and they keep the acuracy for long offsets. CRS gather non hyperbolic approximations, non hyperbolic CRS, fourth order CRS and Padé CRS, have major acuracy than hyperbolic CRS, increasing the convergence of the approximation for offset and CMP domain. The quadratic approximation of fourth order CRS is superior than non hyperbolic CRS approximation, producing less error in least square CRS parameter inversion.Item Acesso aberto (Open Access) Modelagem sísmica acústica e elástica por diferenças finitas e imageamento do depósito de minério de ferro N4WS no estado do Pará(Universidade Federal do Pará, 2017-07-03) HOLANDA, Rafael Mansano; CRUZ, João Carlos Ribeiro; http://lattes.cnpq.br/8498743497664023The finite difference method consists in the numerical resolution of differential equations and one of its applications is a solution of the wave equations or elastodynamics, by replacing the partial derivatives in space and time by their approximations of finite differences. The present work consisted in the accomplishment of the seismic modeling using the method of the finite differences, to acoustic and elastic case. Then, we performed the seismic imaging, to acoustic case, in a model that simulates an iron ore deposit area of N4WS, located in the mineral province of Carajás, in the state of Pará. We found a heterogeneous, isotropic and bidimensional velocity model to acoustic and elastic cases. In order to generate the synthetic seismogram, we executed the program FDSKALAR, to acoustic case, and SOFI2D, to elastic case, using fourth-order approximation of the equation of acoustic and elastic wave in space and time. For a validation of the programs of finite differences and aid in the interpretation of the events, we compared the results with the travel times obtained by the ray theory. After the seismic modeling, we accomplished the processing of the data generate, using the open-source software package Seismic Unix, to obtain an image of the reflector contained in the mineral model. In this way, we searched a better understanding and control on the problems of seismic modeling and imaging, contributing to an interpretation of seismic data and understanding about a seismic wave propagation in environments where there are significant heterogeneities. In addition, we sought to demonstrate the application of seismic methods in the study and delimitation of mineral bodies.Item Acesso aberto (Open Access) Investigação geofísica da contaminação por derivados de hidrocarbonetos nas redondezas do Posto Cristal (Belém-Pa)(Universidade Federal do Pará, 2013) SILVA, Márcio Antonio dos Santos; SILVA, Lúcia Maria da Costa e; http://lattes.cnpq.br/8612431024609774Item Acesso aberto (Open Access) Modelagem do método MT 2D usando elementos finitos isoparamétricos(Universidade Federal do Pará, 2017-04-07) SOUZA JUNIOR, Ivaldevingles Rodrigues de; SILVA, Marcos Welby Correa; http://lattes.cnpq.br/3213216758254128The numerical modeling of the magnetotelluric (MT) method is of great importance for geophysics, since this method can be applied for several purposes, for example it can be used to study the crust of the earth as well as it can contribute to oil and gas exploration. For this reason, several researches have been carried out in recent decades to further develop MT. One of the major advantages of magnetotelluric is its relatively easy modeling, because in this technique the source is a plane wave. Existem varias ferramentas numericas que podem ser usadas para modelar o MT, There are several numerical tools that can be used to model the MT, among which stands out the nite element method (FEM). In this work the eciency of the isoparametric MEF for 2D modeling of the MT will be tested, whose main characteristic is the accomplishment of a transformation, with the purpose of mapping a distorted element to a coordinate system (natural coordinates ξ and η) where it becomes regular.