Peter Vermeer

Interferometric ground-roll removal: Attenuation of scattered surface waves in single-sensor data

Land seismic data are contaminated by surface waves (or ground roll). These surface waves are a form of source-generated noise and can be strongly scattered by near-surface heterogeneities. The resulting scattered ground roll can be particularly difficult to separate from the desired reflection data, especially when this scattered ground roll propagates in the crossline direction. We have used seismic interferometry to estimate scattered surface waves, recorded during an exploration seismic survey, between pairs of receiver locations. Where sources and receivers coincide, these interreceiver surface-wave estimates were adaptively subtracted from the data. This predictive-subtraction process can successfully attenuate scattered surface waves while preserving the valuable reflected arrivals, forming a new method of scattered ground-roll attenuation. We refer to this as interferometric ground-roll removal.

Surface waves: use them then lose them. Surface-wave analysis, inversion and attenuation in land reflection seismic surveying

While in other domains of applied geophysics the surface-wave is considered a source of information for near-surface characterization, in the seismic industry the so-called ground roll has been traditionally regarded only as coherent noise to be filtered out as soon as possible. This difference of perspective is mainly due to the limitations of conventional land acquisition. The Rayleigh waves, which constitute a large part of the recorded energy, can be acquired properly, analysed and inverted to characterize the near-surface with a surprisingly high resolution, even in large 3D surveys, with point receiver acquisition. Surface waves can play a new role: they contribute to a better near-surface characterization for the perturbation correction and can be used for velocity modelling and geological modelling. Their proper identification enables alternative filtering strategies. Surface waves are not coherent noise but a signal that can be lifted from the seismic record and exploited in a variety of well-established geophysical solutions. In this paper we discuss a workflow for the analysis, inversion and attenuation of surface waves with 3D land data, showing examples from a land 3D survey in Egypt.

Statistical multioffset phase analysis for surface-wave processing in laterally varying media

Standard procedures for dispersion analysis of surface waves use multichannel wavefield transforms. By using several receivers, such procedures integrate the information along the entire acquisition array. That approach improves data quality and robustness significantly, but its side effects are spatial averaging and loss of lateral resolution. Recently, a new approach was developed to address that issue and maximize lateral resolution. The new method uses multioffset phase analysis to detect and locate sharp lateral variations in velocity. By using the phase analysis approach, the number of usable channels can be maximized, thereby gaining data quality without compromising lateral resolution. In fact, such preliminary data analysis also allows selection of the appropriate traces on which to perform multichannel processing. Such multioffset phase analysis can be enhanced by f-k filtering, which assures the selection of only one wave-propagation mode, and by a statistical analysis that takes advantage of d...

The impact of acquisition perturbations on land seismic data

Summary Seismic data quality is adversely affected during acquisition by receiver, source, and system perturbations. We present their impact on a structural image derived from land seismic data, using a geophysical sensitivity chart. This chart is obtained by the application of modeled perturbations to synthetic data, which are processed to stack. It shows the relative significance of the perturbations. The most significant errors that we analyzed were due to statics. Acquisition methods and specifications should ensure that the data quality allows an accurate statics solution. We demonstrate the need to focus on reducing the significant perturbations, such as positioning, elevation, tilt, coupling, and statics. For geophone sensitivity, natural frequency and distortion, specifications/tolerances are adequate. For system gain, distortion and synchronization, specifications/tolerances are more than adequate.

Compression of Field Data within System Specifications

Summary Compression of seismic field data can reduce the data volume in acquisition. The concept is that (de-)compressed field data constitute the only available raw data. We could use a lossless compression method to forestall any discussion, but its effectiveness is limited. To achieve higher compression ratios, we propose the use of lossy compression that does not affect the dynamic range of the overall acquisition system and therefore does not affect the data delivered for processing.

“Interferometric ground-roll removal: Attenuation of scattered surface waves in single-sensor data,” GEOPHYSICS, 75, no. 2, SA15–SA25.

To: “Interferometric ground-roll removal: Attenuation of scattered surface waves in single-sensor data,” David F. Halliday, Andrew Curtis, Peter Vermeer, Claudio Strobbia, Anna Glushchenko, Dirk-Jan van Manen, and Johan O. A. Robertsson , Geophysics, 75, no. 2, SA15–SA25.

Interferometric ground-roll removal: Attenuation of scattered surface waves in single-sensor data (vol 75, pg SA15, 2010)

Land seismic data are contaminated by surface waves (or ground roll). These surface waves are a form of source-generated noise and can be strongly scattered by near-surface heterogeneities. The resulting scattered ground roll can be particularly difficult to separate from the desired reflection data, especially when this scattered ground roll propagates in the crossline direction. We have used seismic interferometry to estimate scattered surface waves, recorded during an exploration seismic survey, between pairs of receiver locations. Where sources and receivers coincide, these interreceiver surface-wave estimates were adaptively subtracted from the data. This predictive-subtraction process can successfully attenuate scattered surface waves while preserving the valuable reflected arrivals, forming a new method of scattered ground-roll attenuation. We refer to this as interferometric ground-roll removal.

Interferometric ground-roll removal: Attenuation of scattered surface waves in single-sensor dataInterferometric ground-roll removal

Land seismic data are contaminated by surface waves (or ground roll). These surface waves are a form of source-generated noise and can be strongly scattered by near-surface heterogeneities. The resulting scattered ground roll can be particularly difficult to separate from the desired reflection data, especially when this scattered ground roll propagates in the crossline direction. We have used seismic interferometry to estimate scattered surface waves, recorded during an exploration seismic survey, between pairs of receiver locations. Where sources and receivers coincide, these interreceiver surface-wave estimates were adaptively subtracted from the data. This predictive-subtraction process can successfully attenuate scattered surface waves while preserving the valuable reflected arrivals, forming a new method of scattered ground-roll attenuation. We refer to this as interferometric ground-roll removal.

Meeting the challenge of Mesozoic exploration

The Western Desert of Egypt challenges the exploration for oil and gas both from the reservoir as well as from the surface. The reservoir rocks, Jurassic sandstones and Cretaceous sandstones and carbonates, are often intensely faulted and fractured as a result of the long tectonic history of the area.

A New Look At Scattered Noise Attenuation: Interferometric Ground-roll Removal

Land seismic data is often contaminated by surface waves (or ground roll) that has been scattered by near-surface heterogeneities. The scattered ground roll can be particularly difficult to separate from the desired reflection data. We use both the correlational and convolutional forms of seismic interferometry to successfully estimate scattered ground roll between pairs of receiver locations. This allows for adaptive subtraction of the estimates from source-receiver data, and we refer to this prediction-removal suppression scheme as interferometric ground-roll removal (Curtis et al., 2006; Dong et al., 2006, Halliday et al., 2007).