Artigos Científicos - FAMAT/CCAST
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4088
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Item Acesso aberto (Open Access) Modelagens direta e inversa de dados mCSEM 3D(2011-06) ALMEIDA, Frayzer Lima de; RIJO, LuizMarine Controlled Source Electromagnetic - mCSEM is a new geophysical technology which has been successfully applied to hydrocarbon exploration in the last ten years. This method consists of a horizontal electric dipole (HED) moving just above the sea floor, operating at low frequencies (0.1-1.0 Hz). The fixed receivers distributed regularly on the sea floor capture the electromagnetic fields related with the diffusion of energy generated by the dipole transmitter, the sea water and the sediments, including the petroleum reservoir. In this work we present a finite element algorithm for 3D mCSEM modeling. The performance of the algorithmis illustrated by means of some selected examples in literature. In this work we propose also an algorithm for inversion of three-dimensional mCSEM synthetic datafor two frequencies. Results that illustrate the effectiveness of the proposed algorithm are also discussed.Item Acesso aberto (Open Access) Estimation of fractures orientation from qP reflectivity using multiazimuthal AVO analysis(2002-12) GOMES, Ellen de Nazaré Souza; COSTA, Jessé Carvalho; PROTÁZIO, João dos Santos; SIMÕES FILHO, Ivan de AraújoWe investigate the estimation of fractures orientation, strike and dip, through multiazimuthal AVO analysis of qP and its converted waves qS1 e qS2. We assume weak impedance contrast, weak anisotropy and that the fractured medium behaves as an effective transversally isotropic (TI) medium. Under these assumptions, the estimation of fractures orientation is reduced to the estimation of the orientation of an axis of symmetry from qP reflectivity data. Linearized approximations of qP reflectivity are used for inversion.