Navegando por Assunto "Applied geophysics"

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Acesso aberto (Open Access)
Estudo hidrogeológico através de perfis geofísicos de poços e sondagens elétricas verticais (SEV's) – Salinópolis-Pa
(Universidade Federal do Pará, 2014-02-27) FREIMANN, Boris Chaves; ALVES, José Geraldo das Virgens; http://lattes.cnpq.br/8082136954133058; SILVA, Marcos Welby Correa; http://lattes.cnpq.br/3213216758254128
It was realized a correlation of geophysical well logs from the Sanitation Company of Pará (COSANPA) drilled in the city of Salinópolis for the local supply. The study was conducted in many areas of impound, covering 15 wells. The parameters used in the correlation were Self Potential (SP), Electrical Resistivity (ER) and Gamma Ray (GR). Also, for control purposes, was used the lithological log of the wells obtained from samples of drill cutting. This correlation was conducted to evaluate the lateral continuity of permeable and impermeable layers, in order to develop sections of the subsurface with high accuracy. I was also used Vertical Eletrical Sounding (VES) for comparation efect. It was found the probable existence of two major aquifers that lie 60 meters below sea level and have lateral continuity along the full extent of the studied area. It was also found that the top of the basement in the studied area is around 120 meters below sea level. These findings are extremely important for a better location and constructive evaluation for supply wells in the future projects in the city of Salinópolis-Pa.
Acesso aberto (Open Access)
Modelagem numérica de dados MCSEM 2.5-D
(Universidade Federal do Pará, 2012-04-20) SILVA, Hilton Farias da; SILVA, Marcos Welby Correa; http://lattes.cnpq.br/3213216758254128
This work deals with the implementation of numerical 2.5-D Marine Controlled Source Electromagnetic (MCSEM) modeling applied to hydrocarbon exploration in stratified environment. In the mathematical formulation the fields were assumed to have two parts: the primary and the secondary ones. The first uses of Schelkunoff potentials in its formulation and they were employed in both (x; ky; z; !) and (x; y; z; !) domains. The secondary fields are solved in the frequency domain space (x; ky; z) by finite element method. With a Inverse Fourier transform, the secondary fields were taken in the domain (x; y; z). From the total field, we can show the influence of an oil reservoir in a stratified environment and its sensitivity to the lateral extension of a hydrocarbon reservoir.
Acesso aberto (Open Access)
Utilização de medidas elétricas e eletromagnéticas para a prospecção de água subterrânea em Jacundá (Pa)
(Universidade Federal do Pará, 2014-02-27) MENDES, Marcelo Fernandes; SILVA, Marcos Welby Correa; http://lattes.cnpq.br/3213216758254128
The Jacundá city has a public water system supply in its infancy. From the source surface it is not perennial, small flow and serves less than 20% of the population. Open and shallow tube wells are sources of particular use, limited and seasonal. However, the flow of two deep wells, built in the city, gave evidence that alternative underground water could be a good solution for the local supply. This fact gave rise to a geophysical study to determine the deeper strata permeable. We used nine vertical electrical sounding, whose interpretation acceptd was guided by the geophysical results obtained in a hole. As a result, the models of VES's packets identified two distinct layers resistivity: A package higher, more resistive a total thickness less than 30 meters, was associated with the Itapecuru formation which, is predominantly sandy hydrogeological and weak. And the other, a substrate of low resistivity, it was assumed corresponding to the Codó Formation shales. The interpretation of Slingram data support this result. The hydrogeological potential of this second package is in the shale interbedded sandstone, which may mean the solution for the management of water supply in the city.
Acesso aberto (Open Access)
A viabilidade do método GPR para o mapeamento de camadas de bauxitas laterítica em Paragominas-PA e de goethita em Xambioá-TO
(Universidade Federal do Pará, 2011-08-31) DUARTE, Gildenilson Mendes; SILVA, Marcos Welby Correa; http://lattes.cnpq.br/3213216758254128
In this work we applied the GPR electromagnetic method mapping of layered deposits of minerals in two different environments. Measurements were made with the aim of mapping layers that form deposits of supergene origin of lateritic bauxite, and Goethite. The surveys for the mapping of layers of bauxites were conducted within the mine company Vale and also along the highway PA 256, in the municipality of Paragominas-PA. Resistivity tests were performed within the mine bauxite on a thick capping of clay in an attempt to correlate the variations of resistivity with the lithologic of the studied area, because the GPR measurements were not successful on this capping due the attenuation of the radar wave. The measures for mapping layers Goethite were carried inside a private property, located on the stretch between the towns of Xambioá and Vanderlândia, Tocantins state, near the Araguaia Belt. The study had as main objective to identify parameters such as depth and thickness of mineralized zones, which may aid in the work of exploitation of ores. The results of GPR measurements were very satisfactory, because the method presented a good response for both types of ores investigated, making it possible to characterize the layers and to verification its depths and thicknesses.