Compagnie Generale De Geophysique

Societe Nationale Elf Aquitaine (production)

Sercel Inc.

Cggveritas Services S.a.

Compagnie General De Geophysique

Robert J Garotta

Pierre-Yves Granger

Patrick Burger

Andre Lozes

Serge Vannier

Jean C Vidal

This invention relates to a method for processing seismic data comprising a collection of seismic traces with different offsets, comprising the steps of: a) breaking up one or several first trace(s) of the collection of seismic traces into a series of trace segment's according to a predetermined segmentation interval; b) defining a series of expansion coefficients, each expansion coefficient being associated with a segment of the first trace or traces; c) applying the associated expansion coefficient to each segment of the first trace or traces; d) comparing the first trace or traces thus expanded with a second trace from the collection of seismic traces to evaluate their similarity; e) repeating steps b), and d) with a new series of expansion coefficients, f) determining an optimum series of expansion coefficients that maximizes the similarity between the first expanded trace and the second trace in order to obtain one or several corrected first trace(s).

Correction method for processing seismic traces

A method of seismic processing for obtaining information on the geophysics of the subsoil includes acquiring seismic traces at at least one point on the surface of the subsoil or in the subsoil, the seismic traces corresponding on each occasion to two perpendicular components of a shear wave emitted into the subsoil and reflected by different interfaces therein; applying a succession of transformations (&#x22a5;) at least to a temporal portion of the traces for each of these assumptions, determining the value of a parameter representative of the coherence/similarity between the result traces obtained in this way; and election as a function of the values obtained in this way that one of the hypotheses which is considered as being most representative of the subsoil, the two result traces obtained for said hypothesis being compensated traces of the subsoil birefringency.

Method for seismic processing, in particular for compensating birefringence on seismic traces

Seismic processing methods

Seismic acquisition apparatus comprising a plurality of detectors (s , s , etc.) each constituted by one or more seismic sensors, combiner means which generate at least one seismic trace corresponding to a group of detectors by combining the signals output thereby, and memory means for storing the seismic traces generated in this way, the apparatus being characterized in that it includes seismic preprocessor means (&mgr;P , &mgr;P , etc.) for re-phasing the signals output by the detectors prior to the signals being combined and/or prior to accidental noise on said signals being eliminated.

Device for seismic acquisition

A method of correcting a seismic signal s(t) provided by a vibration sensor (100) in response to at least one emission signal F(t) produced by a least one seismic vibration generator (200). The real emission signal F(t) differs in phase and amplitude relative to a reference emission signal F(t). The correction method of the invention consists in determining the phase difference .DELTA..phi.(f) and the amplitude ratio A(f) between the real emission signal F(t) and the reference emission signal F(t) as a function of frequency f, and in applying the seismic signal s(t) from the vibration sensor (100) to a filter (304) whose response is defined in phase and amplitude respectively by -.DELTA..phi.(f) and by 1/A(f).

Method and apparatus for correcting the response of seismic sensors to

In a method and device for the study of surface layers and subjacent layers of interest, the device comprises receivers and at least two transmission sources spaced at a distance such that a set of traces produced by one of the transmission sources does not interfere with a set of traces produced by the other transmission source when the two sets of traces are on the same time-section.

Method and device for optimization of seismic data

The invention relates to seismic prospecting of the sub-surface. At least two adjacent focuses F and F', at least one reflecting interface H and directions such as (D.sub.1) and (D.sub.2) are selected in the sub-surface. A seismic trace, from which a portion containing the effect due to the reflecting interval is extracted, is made to correspond to each direction and to each focus. The correlation function between the two trace portions relative to two adjacent focuses and the same direction is then determined. The correlation functions obtained are finally summed for the different directions. Application to high resolution seismic prospecting.

Process and an apparatus for seismic geophysics with processing by

A seismic exploration process consisting of the application to the surface of the soil of a plurality of vertical impacts at points separated by a vertical trench cut into the soil. The vibrations propagating in the soil as a result of said impacts are then recorded, with the longitudinal wave components being eliminated from consideration. This makes it possible to produce agitation having a strong transverse wave component.

Growing community of inventors

Chatenay Malabry, France

Robert J Garotta