Abstract: 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.

Abstract: Computing device, computer instructions and method for denoising seismic data recorded with seismic receivers. The method includes receiving the seismic data recorded with the seismic receivers, wherein the seismic data is recorded in a time-space domain; applying with a computing device a high resolution transform to the seismic data in the time-space domain to obtain transformed seismic data in a different domain than the time-space domain, such that the method is amplitude preserving; determining regions of noise and regions of true signal in the transformed seismic data; scaling down the regions of noise; and reverse transforming the transformed seismic data to the time-space domain.

Abstract: Device and method for smoothing an original velocity model of a given subsurface such that a travel-time through the given subsurface is preserved. The method includes receiving the original velocity model, wherein the original velocity model has a set of model parameters that determine a given parameterization and the original velocity model has velocity discontinuities at various depths; selecting a sub-set of model parameters of the given parameterization; converting the selected sub-set of model parameters to composite parameters; smoothing with a processor the composite parameters by applying a convolutional filter (g) such that velocity moments are preserved at the velocity discontinuities; and generating a smooth velocity model by converting the smoothed composite parameters into a smoothed sub-set of model parameters.

Abstract: 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.

Abstract: Apparatus, computer instructions and method for de-pegging seismic data related to a subsurface of a body of water. The method includes receiving as input recorded seismic data (H, G), wherein the recorded seismic data is recorded with a receiver having at least three components; extracting a three-dimensional (3D) gather from the recorded seismic data (H, G); separating up-going and down-going components (U, D) from the 3D gather using a 3D calibration operator (Gcal); and calculating de-pegged seismic data (P) based on the up-going and down-going components (U, D). The de-pegged seismic data (P) is calculated with no radon transform.

Abstract: Computing device and method for determining primary and ghost components from S-waves recorded in near-surface conditions, wherein the S-waves are refracted or reflected from a structure in a subsurface. The method includes a step of receiving seismic data (R, V) with regard to the S-waves, wherein the seismic data includes vertical and radial components recorded with a buried three-component receiver; a step of calculating with a processor a primary component (P) and a ghost component (G) from the vertical and radial components; and a step of computing an image of a subsurface based on the primary and ghost components (P, G). The S-waves form a plane wave.

Abstract: A portable seismic source for generating a seismic wave in the ground. The portable seismic source includes a casing containing an impulsive energy device; a base plate configured to be placed on the ground; and a stabilizing foot mechanism configured to be provided between the casing and the base plate. The stabilizing foot mechanism includes a stabilizer which is fixed relative to the casing and configured to be placed on the base plate and a stanchion that is configured to move relative to the stabilizer and to enter through the stabilizer and apply a force on the base plate when energy is applied from the impulsive energy device.

Abstract: 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.

Abstract: The invention relates to a method for monitoring a subsoil zone, wherein a plurality of receivers are arranged on a surface of the soil or near said surface, straight above a geological zone to be monitored, comprising the following steps: generating a set of reference seismic data recording seismic data by means of said receivers; correlating the seismic data recorded (52) with the reference seismic data; comparing each trace of the correlated data, with correlated traces located in a vicinity of said trace, in order to evaluate a similarity of each correlated trace with the adjacent correlated traces, detecting a microseismic event occurring in the subsoil zone by analysing said similarity. This method enables real-time monitoring.

Abstract: Method of determining the velocity V and anellipticity ? parameters for processing seismic traces in a common midpoint (CMP) gather comprising:—a preliminary step to define a plurality of nodes (dtn, ?o), for each node (dtn, ?o) defined in the preliminary step, the following steps:—for static NMO correction of traces in the CMP gather as a function of the values of the said parameters dtn and ?o at the node considered, and calculation of the semblance function associated with the said NMO correction for the node considered; and—for each picked time to, a step including determination of the maximum semblance node (dtn (to), ?o (to)),—and a final step to convert the dtn (to) and ?o (to) parameters, so as to obtain the velocity to) and anellepticity ? (to) laws.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: The invention concerns a method of acquiring vibroseismic data concerning a zone of the subsoil. This method comprises the following steps: —operating a vibroseismic source so that it transmits a first vibroseismic signal having a first amplitude (101, 201), —operating the source so that it transmits a second vibroseismic signal having a second amplitude different from the first amplitude (103, 203), —recording first data corresponding to the first signal after propagation in the medium to be explored (102, 202), —recording second data corresponding to the second signal after propagation in the medium to be explored (104, 204). The method supplies information for filtering the surface waves (ground roll).

Abstract: A system for seismic exploration of a submerged sub-surface comprises a plurality of bases (4) located at predetermined seabed positions, each base comprising an elongate stem penetrating the seabed, at least a seismic sensor (10, 12) within said stem, a radially extending support zone (19) connected to the upper end of the stem, said upper end projecting from the seabed, and a respective plurality of modules (6) each incorporating a data storage unit and a power source, each module being mechanically and electrically connected to the upper end of said stem, said module being capable of being connected to, and disconnected from, the base by an underwater vehicle.

Abstract: A method for processing seismic data, characterized in that with a view to analyzing them as a function of at least four dimensions. Picking and/or picking propagation is carried out on at least one subset of data which corresponds to a collection of data sampled in three or two dimensions. The quantity or quantities which correspond to the other dimension or dimensions are fixed values. In applying a given projection law to at least one of the points highlighted by the picking and/or picking propagation to determine a point that corresponds to it in another subset corresponding to a collection of data sampled in the same dimensions for a different value of at least one quantity that corresponds to at least one other dimension.

Abstract: The invention relates to a method for seismic exploration, comprising the steps of controlling a plurality of sources so that they emit a plurality of seismic waves in a subsurface zone to be explored, each source successively occupying a plurality of emitter positions, producing for each emission a signal representative of the emission, and recording the position of the source and the instant at which the emission starts, continuously recording by means of seismic sensors the composite signals reflected by the medium in response to said emissions, and carrying out shot point migration, on the one hand, from a reflected wave field constituted of said composite signals and respective sensor positions, and on the other hand, from an incident wave field constituted of signals representative of the emissions, source positions and start emission instants, so as to obtain a seismic image.

Abstract: 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.

Abstract: Seismic processing method, in which, in order to eliminate multiple reflections on seismic data, seismic data are migrated in time or in depth (110) arid the data thus migrated are processed to determine an approximation of multiple reflections to be subtracted from, seismic data (120 to 160).

Abstract: The invention relates to a method for acquiring seismic data at a plurality of positions spread out over a zone on the seabed which includes transmitting acoustic waves in the water layer above the zone by a plurality of sources, —for each of the acquisition positions, dropping from the surface a seismic acquisition equipment, the equipment comprising a seismic acquisition unit and autonomous guiding equipment adapted to receive whilst descending acoustic signals from the sources and to control its trajectory according to the received acoustic signals so as to direct said equipment towards said position, —performing the seismic acquisition, —causing the acquisition equipments to move up to the surface, and —retrieving the acquisition equipments on the surface.