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: 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: Methods and systems for shear noise attenuation based on matching vertical particle velocity data and pressure data are described. The shear noise attenuation is based on the fact that different stages of the analysis can be performed with different numbers of wavelet orientations. The analysis is performed for frequency sub-bands for all wave numbers and vice versa.

Abstract: A method for seismic prospecting that includes a step of deploying plural vibratory sources on the ground; a step of receiving at each vibratory source a corresponding pilot signal for driving the vibratory source; a step of asynchronously actuating the vibratory sources to generate seismic waves into the ground; and a step of continuously recording seismic signals produced by the seismic waves. Pilot signals for the plural vibratory sources are obtained by spectrally shaping starting sequences into continuous pseudorandom sequences that are weakly correlated over a predetermined time interval.

Abstract: The invention concerns a device for emitting seismic waves designed to operate by being towed by a vessel, characterized in that it comprises means capable of discharging compressed air under high pressure into water, to generate a bubble (44) of a general annular shape.

Abstract: Method for separating signals recorded by a seismic receiver and generated with at least two vibratory seismic sources driven with no listening time. The method includes receiving seismic data that includes data d recorded by the seismic receiver and data related to the first and second vibratory seismic sources; computing a source separation matrix based on the data related to the first and second vibratory seismic sources; calculating first and second earth impulse responses HA and HB corresponding to the two vibratory seismic sources, respectively, based on the data d recorded by the seismic receiver, the data related to the two vibratory seismic sources and the source separation matrix; and separating the signals recorded by the seismic receiver based on the first and second earth impulse responses HA and HB such that signals the two vibratory seismic sources are disentangled.

Abstract: Method for separating signals recorded by a seismic receiver and generated with at least two vibratory seismic sources driven with no listening time. The method includes receiving seismic data that includes data d recorded by the seismic receiver and data related to the first and second vibratory seismic sources; computing a source separation matrix based on the data related to the first and second vibratory seismic sources; calculating first and second earth impulse responses HA and HB corresponding to the two vibratory seismic sources, respectively, based on the data d recorded by the seismic receiver, the data related to the two vibratory seismic sources and the source separation matrix; and separating the signals recorded by the seismic receiver based on the first and second earth impulse responses HA and HB such that signals the two vibratory seismic sources are disentangled.

Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data generated by actuating the one or more land seismic source with a first sweep and a second sweep; calculating with a computing device a first earth response corresponding to the first sweep; calculating with the computing device a second earth response corresponding to the second sweep; and calculating the intermodulation noise based on the first and second earth responses. The second sweep is a time reverse sweep of the first sweep.

Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data (g) generated by actuating the one or more land seismic source with a single sweep; selecting a number of detectors (a-f) that detect a subset (ga-gf) of the seismic data (g); estimating earth responses (ha1-hf1) based on (i) the subset seismic data (ga-gf) and (ii) a ground force (gf) of the one or more land seismic source; calculating plural intermodulation noises (noiseA1-noiseF1) for the number of detectors based on the earth responses (ha1-hf1); and removing the plural intermodulation noises (noiseA1-noiseF1) from corresponding detector signals (ga-gf) to mitigate the intermodulation noise effect.

Abstract: Controller and method for determining a driving signal of a vibro-acoustic source element that is configured to generate acoustic waves in water. The method includes estimating at least one physical constraint of the vibro-acoustic source element; modeling a ghost function determined by a surface of the water; setting a target energy spectrum density to be emitted by the vibro-acoustic source element during the driving signal; and determining the driving signal in a controller based on at least one physical constraint, the ghost function, and the target energy spectrum density.

Abstract: This invention relates to a method for processing at least two seismic data sets (10, 20), each data set comprising several seismic traces (i, j) grouped by bins (Bi, Bj) and by offset classes (Oi, Oj), the method including the following steps: calculating at least one attribute (a(i, j)) characteristic of a similarity between a first trace (i) of a first data set (10) and a second trace (j) of a second data set (20), selecting or not the first and second traces (i, j) according to a selection criterion applied to the calculated attribute (a(i, j)).

Abstract: A marine node for recording seismic waves underwater. The node includes a main body having a torus shape; a central body provided inside a space defined by the main body and connected to the main body through at least a link; a first thruster provided in the main body and configured to propel the main body along a central axis (Z) of the main body; and a seismic sensor configured to record the seismic waves underwater.

Abstract: A device, medium and method for de-blending seismic data associated with a subsurface of the earth. The method includes a step of receiving seismic data “d” recorded with one or more land receivers, wherein the seismic data includes shot recordings generated by plural sources that are simultaneously actuated; a step of forming either a continuous receiver trace or trace segments from the received seismic data; a step of selecting plural overlapping spatial blocks that cover the surface shot locations; a step of assigning the shot recordings to the plural overlapping spatial blocks; a step of applying a mathematical technique to the recordings to determine de-blended data; and a step of generating an image of the subsurface based on the de-blended data.

Abstract: A method, an apparatus and a computer-readable medium for processing seismic data are provided. The method includes selecting well-imaged areas of a sediment-to-salt interface, and performing (1) a dual-flood RTM with prismatic waves to identify new areas of the sediment-to-salt interface, and (2) one or more RTM to identify other new areas of the sediment-to-salt interface or of a salt-to-sediment interface.

Abstract: Methods and systems for variable wavelet correction are described. A variable depth dataset is deghosted before presentation to a multiples prediction step of multiples elimination model. In another aspect, the multiples prediction is reghosted before presentation to an adaptive subtraction step of the multiples elimination model. A source-side zero-phasing signature can be applied before deghosting and a predefined gain can be applied in the low and high frequency sides as part of deghosting and reghosting to compensate for the squaring effect produced by convolving wavelets.

Abstract: Method for generating an excitation signal for a first vibratory seismic source so that the first vibratory seismic source is driven with no listening time. The method includes a step of determining a first target spectrum for the first vibratory seismic source; a step of setting a first group of constraints for the first vibratory seismic source; and a step of generating a first excitation signal for the first vibratory seismic source based on the first group of constraints and the first target spectrum. The first seismic traces recorded with plural receivers can be identified when the first vibratory seismic source is driven with no listening time, based on the first excitation signal.

Abstract: Methods and systems for compensating for source and receiver ghost effects in a reverse time migration (RTM) equation are described. Boundary conditions associated with the RTM acoustic wave equations for the source and recorded wavefields are modified. The resultant modified RTM acoustic wave equations are solved to generate ghost compensated modeled seismic images. In another aspect an imaging condition is also modified and the resultant RTM acoustic wave equations are solved to generate velocity and impedance perturbation images.

Abstract: Methods and systems for variable wavelet correction are described. A variable depth dataset is deghosted before presentation to a multiples prediction step of multiples elimination model. In another aspect, the multiples prediction is reghosted before presentation to and adaptive subtraction step of the multiples elimination model. A source-side zero-phasing signature can be applied before deghosting and a predefined gain can be applied in the low and high frequency sides as part of deghosting and reghosting to compensate for the squaring effect produced by convolving wavelets.