Cggveritas Services S.a.

Cgg Services Sas

Compagnie Generale De Geophysique

Cgg Services Sa

Compagnie General De Geophysique

Cgg Veritas Sa

Robert Soubaras

Yu Zhang

Julien Meunier

A method for exploring a geological formation estimates a multiple-inclusive source wavelet and a reflectivity model by performing an inversion minimizing the difference between the shot records and modeled shots. The modeled shots, that include primaries and multiples, are obtained by propagating up-going and down-going wavefields through an input velocity model, which is not updated during the inversion. The shot records are converted into a geological product suitable for hydrocarbon exploration in the geological formation using the multiple-inclusive source wavelet and the reflectivity model.

Method for seismic exploration using a multiple-inclusive source wavelet

A method for determining a shape of a streamer to be towed under water for collecting seismic data. The method includes receiving a velocity model for the subsurface; selecting a first profile for a streamer to be used to survey the subsurface; calculating ghosts and/or residual ghosts and/or residual ghost spectra for a plurality of reflectors of the subsurface; and determining that the first profile is appropriate for surveying the subsurface when at least one criterion, related to the ghosts, residual ghosts and/or residual ghost spectra is met.

Device and method to determine shape of streamer

Apparatus, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes inputting data recorded by detectors that are towed by a vessel, the data being associated with waves travelling from the subsurface to the detectors; applying a migration procedure to the data to determine a first image of the subsurface; applying a mirror migration procedure to the data to determine a second image of the subsurface; joint deconvoluting the first image and the second image for deghosting a reflectivity of the subsurface; and generating a final image of the subsurface based on the deghosted reflectivity of the joint deconvoluting step.

Method and apparatus for deghosting seismic data

Apparatus, computer instructions and method for processing seismic data related to a subsurface of a body of water. The method includes inputting data indicative of recordings made by detectors disposed on a depth-changing profile in response to an acoustic wave reflected from the subsurface; applying a matched mirror migration procedure to the data, wherein the matched mirror migration procedure uses an up-traveling U wave and a down-traveling D wave, at least one of the up-traveling U wave or the down-traveling D wave being constructed based on (i) actual positions of the detectors disposed on the depth-changing profile and corresponding recordings, and (ii) fictitious mirror positions of the actual detectors on the depth-changing profile and corresponding recordings with a changed sign; and generating in a processor an image of the subsurface based on the matched mirror migration procedure.

Method and device for processing seismic data

Streamer and method for deploying the streamer for seismic data acquisition related to a subsurface of a body of water. The method includes a step of releasing into the body of water, from a vessel, a body having a predetermined length together with plural detectors provided along the body; a step of towing the body and the plural detectors such that the plural detectors are submerged; and a step of configuring plural birds provided along the body, to float at a predetermined depth from a surface of the water such that a first portion of the body has a curved profile while being towed underwater.

Method and device to acquire seismic data

Computing device and method for processing seismic traces to produce an image of a subsurface area. The method includes receiving a series of seismic traces related to the subsurface area and recorded by one or more seismic receivers, wherein the one or more seismic sources are originally generated by a source; applying a phase encoding function to the series of seismic traces, at least a portion of said seismic traces comprise signals reflected by geological interfaces of the subsurface area; applying a 3 dimensional (3D) harmonic-source reverse time migration of the series of seismic traces encoded with the phase encoding function; computing a forward wavefield by solving a first wave equation; computing a backward wavefield by solving a second wave equation; and cross-correlating the forward wavefield with the backward wavefield to generate an image of the subsurface.

3-D harmonic-source reverse time migration systems and methods for seismic data analysis

A method for deghosting seismic data collected with a seismic system, the seismic data being related to a subsurface of a body of water. The method includes receiving the seismic data recorded by detectors distributed along a variable-depth profile; calculating migrated (d) and mirror-migrated (d) gathers based on the seismic data, wherein the migrated and mirror-migrated gathers depend on a feature characterizing a configuration of the seismic system; applying a joint deconvolution model to the migrated and mirror-migrated gathers (d, d) to calculate a single deghosted gather (dg); and generating a final image of the subsurface based on the single deghosted gather (dg). The feature is not present in a gather after a step of stacking that is performed prior to generating the final image.

Method and apparatus for pre-stack deghosting of seismic data

Apparatus, computer instructions and method for processing seismic data related to a subsurface of a body of water. The method includes inputting data indicative of recordings made by detectors provided on a depth-changing profile in response to an acoustic wave reflected from the subsurface; applying a matched mirror migration procedure to the data, where (i) actual positions of the detectors on the depth-changing profile and corresponding recordings, and (ii) fictitious mirror positions of the actual detectors on the depth-changing profile and corresponding recordings with a changed sign are added in the matched mirror migration; and generating a final image of the subsurface based on the matched mirror migration procedure.

Apparatus, computer instructions and method for processing seismic data related to a subsurface of a body of water. The method includes inputting data indicative of recordings made by detectors provided on a curved profile in response to an acoustic wave reflected from the subsurface; applying a matched mirror migration procedure to the data, where (i) actual positions of the detectors on the curved profile and corresponding recordings, and (ii) fictitious mirror positions of the actual detectors on the curved profile and corresponding recordings with a changed sign are added in the matched mirror migration; and generating a final image of the subsurface based on the matched mirror migration procedure.

The invention concerns a method to acquire seismic waves by means of a streamer towed by a vessel and comprising a plurality of seismic receivers. The streamer comprises a head portion that is slanted relative to the water surface and a tail portion having at least one section with a different slant.

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Orsay, France

Robert Soubaras