Abstract: Device and method for processing 4-dimensional (4-D) seismic traces. The method includes receiving at least two vintages of seismic traces recorded by seismic receivers for a same subsurface area, wherein said seismic receivers are located at the ocean floor; applying up-down deconvolution to each of said vintages of seismic traces to obtain a representation of a reflectivity of said subsurface area from each vintage of seismic traces; and redatuming the up-down deconvolution result of each vintage from the ocean floor to a desired water depth of the ocean to reduce one or more changes in said seismic traces associated with water layer variations between recordings of said series of seismic traces. The redatumed seismic data is used to generate one or more images representing characteristics of said subsurface area.

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: Method and marine acoustic source array for generating an acoustic wave in a body of water. The marine acoustic source array includes first and second external source sub-arrays, each sub-array including one or more individual source elements; a first actuator device connected to the first external source sub-array; and a second actuator device connected to the second external source sub-array. The first actuator device has a corresponding cable configured to connect to a first lead-in, and the second actuator device has a corresponding cable configured to connect to a second lead-in such that a position of the source array as a whole is controllable along a line substantially perpendicular to a path of the source array.

Abstract: A marine acoustic source system for generating an acoustic wave in a body of water. The marine acoustic source system includes a first marine acoustic source array having first and second external source sub-arrays, each sub-array including one or more individual source elements; a first actuator device connected to the first external source sub-array; and a first rope connecting the first actuator device to a first lead-in that is configured to connect to a head of a streamer. The first actuator device is configured to control a length of the first rope in order to control a position of the first source array relative to the streamer.

Abstract: Method and vessel for performing marine acoustic survey of a subsurface. The vessel includes a launching module configured to deploy an autonomous underwater vehicle (AUV) underwater; a recovery module configured to recover the AUV; a homing device mounted on the recovery module and configured to guide the AUV to the recovery module; and a management module connecting the launching module to the recovery module and configured to transport the AUV.

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: 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: 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: Methods and systems allow for performing maintenance on a deployed portion of a seismic streamer. A method for raising and lowering a portion of a spread associated with a seismic streamer which is towed by a mother ship, the method including: configuring a device to be movable, wherein the device includes at least two buoyant structures connected by a platform, further wherein the platform includes a winch, a motor and controls associated with the winch and the motor; deploying the device from the mother ship overtop of the portion of the spread to be raised; lowering a line from the device via a winch to a position proximate the portion of the spread to be raised; connecting the line to the portion of the spread; and raising the line and the portion of the spread via the winch to a surface of a body of water.

Abstract: The invention relates to a source device for the emission of seismic waves designed to operate by being towed by a vessel. The source device according to the invention comprises at least three support-beams, a plurality of guns placed along each support-beam, a central hub receiving one end of support-beams and arranged such that support-beams can be deployed according to a star-like geometry, and the means to keep support-beams in this geometry during operation.

Abstract: Method and fairing to be attached to a cable of a seismic survey system for reducing drag and/or noise. The fairing includes a body having a hydrodynamic shape; a tail portion connected to the body; and a head portion connected to the body, opposite to the tail portion, and configured to be removably clamped-on to the cable. The head portion, the body and the tail portion extend in this order along a traveling direction.

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: 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, 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 streamer steering device to be attached to a streamer or a source of a marine seismic survey system. The streamer steering device includes a casing configured to be attached to the streamer or to the source; a wing assembly connected to the casing and having an active surface used to control depth and/or lateral position of the streamer; and an actuating mechanism located inside the casing and connected to the wing assembly, the actuating mechanism being configured to change a state of the wing assembly from an operational state to a folded state. The active surface has substantially the same area during the operational state and the folded state.

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 for increasing similarity between a base seismic survey and a monitor seismic survey of a same surveyed subsurface during a 4-dimensional (4D) project. The method includes receiving first seismic data associated with the base seismic survey; receiving second seismic data associated with the monitor seismic survey, wherein the monitor seismic survey is performed later in time than the base seismic survey; migrating the first and second seismic data to an image-domain; and calculating, with a processor, a set of decimating weights based on the migrated first and second seismic data in the image-domain, to maximize a similarity between the first seismic data and the second seismic data.

Abstract: A method, system and a marine node for recording seismic waves underwater. The node includes a first module configured to house a seismic sensor; bottom and top plates attached to the first module; a second module removably attached to the first module and configured to slide between the bottom and top plates, the second module including a first battery and a data storage device; and a third module removably attached to the first module and configured to slide between the bottom and top plates, the third module including a second battery.

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: Computer software, computer and method for generating with a computing device a desired pilot signal for driving a vibratory source to generate seismic waves. The method includes steps for compressing a pilot signal in a force domain and also compressing a mass displacement in a displacement domain. The resulting desired pilot signal boosts the low-frequency end of the vibratory source.