Application of extinction theorem deghosting method on ocean bottom data

Abstract

As one of the pre‐requisites for multiple removal, imaging and inversion, the effectiveness of deghosting affects the performance of the followed operations. Extinction Theorem based deghosting method has been successfully applied on towed streamer data by Zhang and Weglein (2005b). In that paper, the deghosted data was then processed using inverse scattering series (ISS) free surface multiple removal (FSMR) algorithm and it was shown that using deghosted data and with given source wavelet, that the ISS FSMR can predict the free surface multiples accurately both in time and amplitude. Thus, the ISS FSMR algorithm with appropriate wavelet and deghosting directly predicts and subtracts the free surface multiples without the need of adaptive subtraction. In practice, this will mitigate the need for adaptive subtraction; and its sometimes harmful application that can run at cross purposes to the underlying strength of the ISS FSMR method. In this paper, we apply the same deghosting algorithm on ocean bottom data. With source wavelet available, only pressure measurements have been used in the process of deghosting and this avoids the need for the troublesome vertical velocity measurements. The deghosting results agree very well with the exact results calculated using the Cagniard‐de Hoop method.