Multiple Suppression And Attenuation Techniques Of Marine Seismic Data

The demand and dependence on resources rises with the rapid development of world economy. Marine oil-gas exploitation is promoted and marine geological prospecting proves to be hot spot due to the increasingly important social-economic value of the oceans.Seismic prospecting is as ever a principle method to search oil-gas resource.During the marine seismic prospecting, the existence of multiple influences the authenticity and reliability of seismic imaging. Furthermore, it would lead to the distortion of amplitude, frequency and phase of reflection waves from target stratum. The difficult identification interferes the explanation of seismic data and increases the risk of oil-gas exploration. Therefore, multiple is the major noise in marine seismic prospecting.The method to suppress and attenuate multiple is one of the primary subjects in marine seismic prospecting.Firstly, this paper generalizes the causes, classification, and features of multiples. Furthermore, it analyzes the principles and application and summarizes major methods of multiple suppression and attenuation based on the above.The following research is based on the marine seismic data from an exploration area. The study area would be divided into Area A(deep-sea) and Area B(shallow-sea). The multiples vary according to the water depth and eventually call for different methods of suppression and attenuation.According to the original seismic data of frequency spectrum, velocity spectrum, CMP gather, original stack section and single-shot autocorrelation, the main multiples types in Area A are reflected multiples and diffracted multiples, and simple multiples, interbed multiples and reverberation in Area B.Currently, there are a variety of multiple suppression and attenuation techniques, none of which could ultimately suppress and attenuate all types of multiples due to different conditions and applications. Consequently, a combination of technique application might be a more reasonable solution.Cascade Multiple Suppression and Attenuation techniques in Area A include SRME, high-precision Radon transform and noise attenuation in different frequency domain. Whereas Area B consists of deconvolution in TAU-P domain and high-precision Radon transform.This paper analyzes the features of different techniques according to the marine seismic data in application to single-shot, velocity spectrum, CMP gather and data stacking.In conclusion, multiples are dysplastic and extremely powerful during marine seismic processing. The suppression and attenuation is a critical and eternal issue. As a consequence, effective and efficient Cascade Multiple Suppression and Attenuation techniques should be applied to deal with different multiples in different conditions and applications.