Multiple attenuation in the parabolic τ-pdomain using wavefront characteristics of multiple generating primaries

Abstract

The problem of multiple attenuation has been solved only partially. One of the most common methods of attenuating multiples is an approach based on the Radon transform. It is commonly accepted that the parabolic Radon transform method is only able to attenuate multiples with significant moveouts. We propose a new 2-D method for attenuation of both surface‐related and interbed multiples in the parabolic τ-p domain. The method is based on the prediction of a multiple model from the wavefront characteristics of the primary events. Multiple prediction comprises the following steps: 1) For a given multiple code, the angles of emergence and the radii of wavefront curvatures are estimated for primary reflections for each receiver in the common‐shotpoint gather. 2) The intermediate points which compose a specified multiple event are determined for each shot‐receiver pair. 3) Traveltimes of the multiples are calculated. Wavefields within time windows around the predicted traveltime curves may be considered as multiple model traces which we use for multiple attenuation process. Using the predicted multiple traveltimes, we can define the area in the τ-p domain which contains the main energy of the multiple event. Resolution improvement of the parabolic Radon operator can be achieved through a simple multiplication of each sample in the τ-p space by a nonlinear semblance function. In this work, we follow the idea of defining the multiple reject areas automatically by comparing the energy of the multiple model and the original input data in the τ-p space. We illustrate the usefulness of this algorithm for the attenuation of multiples on both synthetic and real data.

Gabor deconvolution: Estimating reflectivity by nonstationary deconvolution of seismic data

“…Furthermore, the nature of the data gather being deconvolved is also relevant as it is with Robinson deconvolution. For example, we have anecdotal evidence that the suppression of interbed multiples might be enhanced when deconvolving tau-p gathers, as is the case for Robinson deconvolution (e.g., Treitel et al, 1982;Landa et al, 1999).…”

Separation and imaging of seismic diffractions using migrated dip-angle gathers

“…After focusing, events of different types can be separated. In particular, primaries and multiples having different velocities can be separated in the Radon domain, which is widely used as a demultiple tool (Foster and Mosher, 1992;Landa et al, 1999). If events are defined by different equations (as reflections and diffractions are in the migrated dip-angle domain), it is more appropriate to focus them using the hybrid Radon transform.…”

Data-driven, target-oriented, kinematic prediction and subtraction of multiples from pure and mode-converted multicomponent data

“…Ma et al (2009) effectively separate free-surface multiples from primaries by muting multiples in the coupled plane-wave domain. Landa et al (1999a) suppress multiples in the τ − p domain.…”