Modelagem sísmica por diferenças finitas em meios bidimensionais com difratores
The subject of this work is the seismic modeling in medium with strong discontinuities in physical properties with enphasis in diffractions events. This research intend to contribute for a better comprehension and control of seismic modeling in complex medium. According to various authors, the Am...
| Autor principal: | FERNANDES, Lindemberg Lima |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Universidade Federal do Pará
2014
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| Assuntos: | |
| Acesso em linha: |
http://repositorio.ufpa.br/jspui/handle/2011/6072 |
| Resumo: |
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The subject of this work is the seismic modeling in medium with strong discontinuities in
physical properties with enphasis in diffractions events.
This research intend to contribute for a better comprehension and control of seismic
modeling in complex medium. According to various authors, the Amazon Basin is formed by sedimentary rocks
deposited since the Ordovician to the present, reaching depth up to 5 Km. The bodies of basalt
between the paleozoic sediments are arranged as basaltic layers reaching thickness of hundred
meters, which add to 90,000 km3. The ocurrence of these structures is responsible for the
existence of multiple reflections during the propagation of the seismic waves, which makes
impossible a better imaging of horizons located bellow the basaltic layers
An accoustic velocity model was used to demonstrate this geological situation. The
seismograms were calculated with a program of finite-difference with a fourth order
aproximation of the acoustic wave equation in space and time. The aplication of the finite-difference method for modeling the propagation of the seismic
waves has improved the understanding of the wave propagation in significant heterogeneous
medium and achieves a good resolution in the interpretation of seismic reflection events in areas
of interest
As a result of numerical experiments accomplished in a complex geological medium a
significant influence due to multiple reflection observed in a high velocity layer causing an
increase in a loss of energy that made the data more dificult to analise. Because of this problem I
advise the integration of the data from both surface and wells, to achieve a better imaging below
the basaltic layer. |