CONVENTIONAL STREAMER DATA DEGHOSTING USING FREQUENCY-VARYING REFLECTION COEFFICIENT FOR AN IMPROVED DECONVOLUTION (KEY IJP************179)

• Paula Ukerun,Dr. Sylvester Ugwu ,Rasaki Salami

Abstract

In this study, we present the benefits of applying source and receiver sides ghost removal within optimized frequency bands. The occurrence of multiples in the seismic signal limits the resolution of seismic events. In most conventional seismic surveys, short-period multiples are generated from downward reflections of seismic waves by the sea surface on the source and receiver sides; with a reflection coefficient close to -1, which varies with the angle of incidence. Using data-derived deghosting operators can improve signal resolution and seismic bandwidth for more accurate subsurface imaging. The data used in this research had a nominal source depth of 5m and receiver depth of 8m, giving a source and receiver notch frequencies of 150Hz and 94Hz respectively. Deconvolution in the F-K (Stolt) migration domain showed an improvement in signal resolution with the removal of the source and receiver sides generated short-period multiples. Higher reflection coefficient estimation for the ghosts improved the low-frequency signal recovery with potential loss in high-frequency signal quality. To optimize the signal-to-noise ratio over the frequency range, frequency-varying reflection coefficients were used in data deghosting in a novel approach; the improved quality of the deghosted data indicates a dependence between the reflection coefficient of the ghost operation and the frequencies.