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: Method, computer device and software for calculating a corrected temporal variation (dt1)depth or a corrected relative temporal variation (dt1/t1)depth of a first body wave based on a second body wave. The method includes receiving raw seismic data recorded with a receiver; calculating arrival-time variations for the first and second body waves; calculating first and second relative temporal variations for the first and second body waves; and correcting the first relative temporal variation based on the second relative temporal variation to obtain the corrected relative temporal variation or correcting the first temporal variation based on the second temporal variation to obtain the corrected temporal variation. The second wave is either a body wave or a surface wave.

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

Abstract: Method, computer device and software for calculating a corrected temporal variation (dt1)depth or a corrected relative temporal variation (dt1/t1)depth of a first body wave based on a second body wave. The method includes receiving raw seismic data recorded with a receiver; calculating arrival-time variations for the first and second body waves; calculating first and second relative temporal variations for the first and second body waves; and correcting the first relative temporal variation based on the second relative temporal variation to obtain the corrected relative temporal variation or correcting the first temporal variation based on the second temporal variation to obtain the corrected temporal variation. A body wave is a wave that experiences at least one reflection before being recorded by the receiver.

Abstract: A device, medium and method for de-blending seismic data associated with a subsurface of the earth. The method includes receiving blended seismic data, wherein the blended seismic data includes traces having energies from two or more different shots that partially overlap; applying an apex-shifted radon transform (ASRT) to the blended seismic data to transform it from a first domain to a second domain; applying a mute processing for removing all shots except a first shot in the second domain; applying a reverse ASRT to the given shot to obtain the first shot in the first domain; and generating an image of the subsurface based on the first shot in the first domain. The procedure may be iteratively repeated to separate all shots.

Abstract: The invention concerns a device for emitting seismic waves designed to operate by being towed by a vessel. The device of the invention comprises a support of elongated shape; at least one seismic source connected to the support; means to tow the support whilst holding it in a substantially vertical position.

Abstract: Computing device and method for generating an image of a subsurface. The method calculates an offset shift of measured offsets between a seismic source and plural receivers of a streamer. The method includes receiving seismic data recorded underwater by the plural receivers; selecting two pairs of traces from the plural traces and for each pair, calculating a quantity Y that depends on measured offsets of receivers for which the traces were selected, and a quantity X that depends on travel-times and the measured offsets of the receivers for which the traces were selected; calculating a linear relation Y=aX+b, where “a” is a constant and “b” is related to the offset shift; estimating the offset shift from “b”; correcting the measured offsets of the receivers based on the offset shift; and calculating the image of the subsurface based on the corrected offsets.

Abstract: Method and system for improving offset/azimuth distribution. The system includes plural streamers towed by a streamer vessel; a central source towed by the streamer vessel; first and second front sources located in front of the plural streamers along a traveling direction of the streamer vessel; and first and second large offset front sources located in front of the first and second front sources along the traveling direction. The offset distance between the first and second large offset front sources, along a cross-line direction, is larger than an offset distance between the first and second front sources.

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: A marine source sub-array and method for generating a pressure wave in a body of water. The marine source sub-array includes a float configured to float in the body of water; base plates connected to the float through cables; plural individual source elements connected to the base plates and configured to generate pressure waves underwater; and a coverage plate located between the plural individual source elements and the float. The coverage plate has a surface area larger than a surface area of the float.

Abstract: Control mechanisms, computer software and methods for driving vibrational source arrays underwater. An incoherent acquisition scheme drives individual source elements simultaneously and incoherently while a coherent acquisition scheme drives high-frequency individual source elements simultaneously and incoherently and low-frequency individual source elements simultaneously and coherently. Thus, denser coverage and an increased energy input is achieved for the source arrays.

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: Control mechanisms, computer software and methods for driving vibrational source arrays underwater. An incoherent acquisition scheme drives individual source elements simultaneously and incoherently while a coherent acquisition scheme drives high-frequency individual source elements simultaneously and incoherently and low-frequency individual source elements simultaneously and coherently. Thus, denser coverage and an increased energy input is achieved for the source arrays.

Abstract: Method, source and seismic vibro-acoustic source element configured to generate acoustic waves under water. The seismic vibro-acoustic source element includes an enclosure having first and second openings; first and second pistons configured to close the first and second openings; an actuator system provided inside the enclosure and configured to actuate the first and second pistons to generate a wave having first frequency; and a pressure mechanism attached to the enclosure and configured to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure.

Abstract: Method, source and seismic vibro-acoustic source element configured to generate acoustic waves under water. The seismic vibro-acoustic source element includes an enclosure having first and second openings; first and second pistons configured to close the first and second openings; an actuator system provided inside the enclosure and configured to actuate the first and second pistons to generate a wave having first frequency; and a pressure mechanism attached to the enclosure and configured to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure.

Abstract: A method and device 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 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; and, detecting a microseismic event occurring in the subsoil zone by analysing said similarity. The method and device enables real-time monitoring.

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: Computing device, software and method for identifying a source mechanism associated with a microseismic event taking place in a subsurface of the earth. The method includes receiving traces associated with a plurality of receivers located in a grid above the subsurface; dividing the grid in a set of sub-blocks, determining, for each sub-block, a corresponding summation element based on traces associated with the corresponding sub-block; identifying a predetermined number of patterns that are associated with plural source mechanisms; multiplying each summation element by a polarization coefficient according to a corresponding pattern; calculating for each pattern, a semblance function based on summation elements of the sub-blocks; and identifying the source mechanism of the microseismic event based on the semblance function.

Abstract: A method, system and a marine node for recording seismic waves underwater. The node includes a body made of a compressible material that has a density similar to a density of the water; a first sensor located in the body and configured to record pressure waves; and a second sensor located in the body and configured to record three dimensional movements. The body is coupled to the water for passing the seismic waves to the first and second sensors.

Abstract: An autonomous underwater vehicle (AUV) for recording seismic signals during a marine seismic survey. The AUV includes a body having a flush shape; an intake water element located on the body and configured to take in water; at least one propulsion nozzle located on the body and configured to eject the water from the intake water element for actuating the AUV; at least one guidance nozzle located on the body and configured to eject water to change a traveling direction of the AUV; and a seismic payload located on the body of the AUV and configured to record seismic signals.