Método sísmico aplicado às bacias de Solimões e Amazonas

Abstract

Seismic methods study the earth using as a tool, the propagation of elastic waves. These waves, when propagated on subsurface, lose energy due to several effects: absorption, spherical divergence and transmission loss. Seismic waves can simply be classified as surface waves and body waves. The body waves are divided into P and S and each of these waves can be characterized by their different speeds. Such velocities vary according to lithology and may be directly related to the petrophysical properties of the rocks that make up the medium. Seismic data is acquired in such a way that noise pickup is avoided as much as possible, so choosing the best parameterization and controlling acquisition operations is so important. Once acquired, the data is properly processed and then analyzed by an interpreter who will use the images obtained to identify possible hydrocarbon accumulations. The processing consists of several steps. The migration stage is one that moves plunging events to their actual positions and collapses the diffraction. It can be performed before or after stacking the strokes. Pre-stack migration provides results that are closer to reality but is more expensive and not always economically viable. We will discuss here an application of the seismic method in an attempt to better imagine basalt sills present in the Solimões basin, northern Brazil.