Processamento e imageamento sísmico usando o CRS

Abstract

This work aimed at the application of the common-reflection-surface stack methods (CRSconventional), of the CRS-partial method, and of the NIP-tomography inversion method, to generate seismic data images for the interpretation related to geologically complex areas. The constructed model, and named Duveneck-Astur, was used to simulate a geological ambient formed by layers limited by smooth surface reflector interfaces, but that the paraxial ray theory was attended, differently from other synthetic common models where the presence of geological faults, and of high horizontal and vertical gradients exist, like in the Marmousi and the Sigsbee models, among others. To analyze comparatively the resolution of the applied methods, two tests were performed with the synthetic data. One test consisted of decimated data with random muting of traces in the CMP families, and another test with addition of noise. It was computer analyzed the behavior of the different stack methods to obtain a depth velocity distribution by NIP-tomography inversion, that uses the kinematic wavefield attribute constraints to estimate a velocity model consistent with the data. NIP-tomography results were mutually compared, and also to the velocity model obtained from semblance velocity analysis. The velocity distribution were used in the PSPI migration to verify consistency in the results.