Wide‐band Velocity Filtering—the Pie‐slice Process

Abstract

A new technique has been developed which makes it possible to process a seismic record‐section in such a way that all seismic events with dips in a given range are preserved with no alteration over a wide frequency band, while all seismic events with dips outside the specified range are uniformly and severely attenuated. By applying this process to a noisy record‐section, a record‐section may be obtained which has all events within a specified dip range perfectly preserved, and very high‐velocity noise essentially eliminated, a result which is impossible by simple wave‐number filtering or conventional array usage. In structurally complex areas where several steeply dipping events interfere, the technique may be applied to separate the events with different dips. In areas where a normal‐moveout contrast exists between primaries and multiples, the technique may be used for wide‐band multiple attenuation. By application of a “rotating Pie‐Slice” to micro‐spread noise data, seismic noise may be separated on the basis of propagation velocity, and a clearer picture of the seismic noise problem obtained. The “rotating Pie‐Slice” also provides a means of uncovering diffractions and other steeply‐curved events from a record section. The paper discusses the motivation and implementation of the process and its application to both synthetic and actual data.

Adaptive Signal Decomposition and Filtering Using Binomial Filters Applied to the Ground-Roll Attenuation

“…The conventional methods can be divided into two groups. The first one can be summarized to filter method which is based on suppression of undesired parts of recorded data in the spectral domain, including high-pass and band-pass filtering, f − k filtering (Embree et al, 1963;Treitel et al, 1967;Yilmaz, 2001) and the adaptive ground-roll attenuation method (Wang et al, 2012;Hosseini et al, 2015). These methods have their limitations.…”

Simple Processing Sequence to VSP-Seismic data matching in Sindbad oil field, south of Iraq

“…Separating waves by velocity pass and reject filters is based on the following concept: waves which desired are signal and everything else is noise [9], [10] & [11]. So signal is passed by the time-correcting it for moveout and applying velocity pass filters that are centered about zero moveout.…”

Determination of an Optimal Processing Flow for the Suppression of Free-Surface Multiples in Real 2d Marine Data

“…in seismic data, and f −k filtering is based on the dip of linear events (Embree et al, 1963). The recorded seismic data (P, the pressure field) are mapped from the time domain into the frequency-wavenumber domain through 2D Fourier transform.…”