Pgs Geophysical As

Gregg E Parkes

Stian Hegna

Francis Drossaert

Norman Daniel Whitmore, Jr

Fabien Julliard

Charles Lameloise

Rune Tonnessen

A method for seismic data processing can include obtaining seismic data acquired based upon trigger times and not based upon positions of triggered source elements. The seismic data can include near-continuously recorded seismic data in split records. The split records can be spliced together into a single near-continuous record to produce a trace with seismic data from a single acquired line. The seismic data can be processed by performing a spatial shift for each of a number of time samples to correct for motion of a number of seismic receivers.

Seismic data processing

A method and apparatus for determining marine seismic source configurations which produce a minimum error after the process of combining the wave fields to eliminate the responses of sources including the source ghost operated at multiple depths, without separating these wave fields, is disclosed. In one embodiment, a method includes simulating, on a computer system, the performing of a seismic survey for one or more source configurations. An error term is calculated for each configuration simulated. Based on the calculated error terms, a configuration having the smallest error among those simulated may be determined.

Method for optimizing the design of multiple-source arrays used in marine seismic surveys

Wavefield separation methods and systems that adjust near-continuous pressure and particle motion wavefields based on distance moved along a vessel track by the sensors when the wavefields were measured are disclosed. Methods and systems correct for the motion of the receivers in towed streamer seismic data in order to obtain a wavefield with approximately stationary-receiver locations. Wavefield separation may then be applied to the wavefield with approximately stationary-receiver locations.

Methods and systems of wavefield separation applied to near-continuously recorded wavefields

In order to avoid complicated and unpredictable effects on the wavefields emitted by air guns activated at different times, methods and systems of the current disclosure are directed to computationally designing a sequence for activating subsets of air guns in a time distributed manner that minimizes the effects of air in the water surrounding the source. The sequence may be used with discrete and continuously recorded marine surveys.

Methods and systems to operate marine sources to avoid air in water effects

Systems and methods to correct source responses and perform source deghosting of a pressure or particle motion wavefield recorded using near-continuous recording of seismic data along a vessel track with generalize source activation times. The methods and systems receive a near-continuously recorded seismic data and generate a near-continuous wavefield for approximately stationary-receiver locations. Time windows of different temporal lengths are applied to traces of the near-continuous wavefield in approximately stationary-receiver locations in order to compute common-receiver gathers. The common-receiver gathers are corrected source wavefield response and source ghost effects and are combined in weighted sums to generate broadband seismic data.

Methods and systems that combine wavefields associated with generalized source activation times and near-continuously recorded seismic data

A method for seismic data acquisition can include near-continuously recording seismic data received from a number of seismic receivers and triggering a plurality of source elements, based upon time and not based upon position, at a predefined sequence of times relative to a start of a near-continuous recording.

Seismic data acquisition

Techniques are disclosed relating to testing of seismic air guns, for example via bubble tests. According to some embodiments of these techniques, a firing sequence for testing the air guns may be determined that reduces the amount of interaction between firings. Further, firing time delays may also be determined in order to further reduce the interactions. Accordingly, a test of an array of air guns may be completed relatively quickly.

Time-efficient tests to detect air gun faults

Systems and methods for operating a seismic source to attenuate shot generated noise, or residual energy from previous activation of the source, in recorded seismic data are described. In one aspect, methods operate a single seismic source towed through a body of water along a survey track. As the survey vessel travels along the survey track, the source is activated at the end of randomly selected time delays, resulting in attenuation of shot generated noise. The method also attenuates other forms of coherent noise that align from shot to shot.

Systems and methods for removing acquisition related effects from seismic data

Systems and methods for imaging subterranean formations using primary and multiple reflections are described. An exploration-seismology vessel tows a seismic source, a receiver acquisition surface located beneath a free surface, and a source acquisition surface positioned at a depth below the source. The receiver acquisition surface is used to measure pressure and normal velocity wavefields and the source acquisition surface is used to measure direct, down-going, source pressure wavefields generated by the source. The down-going source pressure wavefields in combination with the down-going pressure wavefields and up-going pressure wavefields computed from the pressure and velocity wavefields are used to compute images of the subterranean formation associated with primary reflections and multiple reflections.

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Weybridge, United Kingdom

Gregg E Parkes