Abstract

Seismic imaging in fold belt regime has always been a major challenge for acquisition and processing geophysicists in the world. Most of the time conventional processing schemes fail to produce the best possible image of the subsurface in the presence of strong noise and weak signal strength. A different processing scheme was formulated to enhance the signal strength. Moreover it was felt necessary to first understand the nature of prevailing dominant noises. First of all raw shot gathers were thoroughly analyzed for different types of source generated noise (e.g. direct, refracted, surface and air waves) masking the signal. Analysis of frequency spectra of different portions of the raw shot, figure 1(a), showed that it was contaminated with high amplitude source generated noise characterized by low and high frequencies and the signal content of the data was 10-55 Hz. These processing tests suggested that the best way to attenuate these noises and enhance the signal to useful signal band of 10-55 hertz was to apply spiking deconvolution and spectral balancing on a trace-by-trace basis