Abstract: A system and method for performing a marine seismic survey of a subsurface. The method includes deploying under water, from a deploying vessel, an autonomous underwater vehicle (AUV); recording with seismic sensors located on the AUV seismic waves generated by an acoustic source array; instructing the AUV to surface at a certain depth relative to the water surface; recovering the AUV by bringing the AUV on a recovery vessel; and transferring recorded seismic data to the recovery vessel.

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: A method for determining a shape of a streamer to be towed under water for collecting seismic data. The method includes receiving a velocity model for the subsurface; selecting a first profile for a streamer to be used to survey the subsurface; calculating ghosts and/or residual ghosts and/or residual ghost spectra for a plurality of reflectors of the subsurface; and determining that the first profile is appropriate for surveying the subsurface when at least one criterion, related to the ghosts, residual ghosts and/or residual ghost spectra is met.

Abstract: Systems and methods according to these exemplary embodiments provide for attenuating noise which interferes with recordings of a seismic source. A method includes: generating a reference trace for a noise source; generating a primary trace for the seismic source; generating a first estimated convolutional operator between the reference trace and the primary trace; convolving the operator with the reference trace for a time frame to generate an estimated noise for the time frame; and subtracting the estimated noise from the primary trace to generate an output signal.

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 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: The invention concerns a passive monitoring method to detect the presence of and characterize a micro-seismic event (3) occurring in the subsurface, by processing seismic data recorded by a plurality of seismic receivers (R1, Rn) arranged on the earth surface (4), said seismic data comprising acquisition noise and a wave field (6) generated by the micro-seismic event, said wave field being drowned in the noise, the method comprising the performing of waveform inversion directly on the seismic data recorded by the seismic receivers with no prior detection of the wave field generated by the micro-seismic event.

Abstract: Seismic data acquisition system, method, and connecting part configured to connect a lead-in to a streamer. The connecting part includes a single body extending along a longitudinal axis (X) between the lead-in and the streamer; the single body has a first end configured to connect to the lead-in through a first connection device and the body also has a second end configured to connect to the streamer through a second connection device; at least a link connecting the first end to the second end and configured to receive a tension that appears in the single body; a cable extending through the single body and configured to provide data communications; and plural modules provided on the single body. The single body is configured to wound-up on a spool.

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: Device and method for estimating an event-related main anisotropy axis for a volume in a subsurface. The method includes selecting a velocity migration model for the given volume of the subsurface; receiving seismic data for the given volume; migrating the seismic data based on the velocity migration model; picking locally coherent events from the migrated data; and performing a tomographic process based on invariants to calculate the event-related main anisotropy axis.

Abstract: Method and support assembly configured to change from a stowing position to an operational position. The support assembly includes a head module; an actuator attached to the head module; a tail module; plural modules provided between the head module and the tail module to form a first branch and a second branch, each branch being connected between the head module and the tail module; and a cable system provided through the means for guiding of the plural modules and connected to the actuator for being wind up and unwind to change a distribution of the modules from an operational position to a stowed position.

Abstract: Method and system for determining positions of underwater sensors. The method includes sending a Doppler variant signal from a moving source; recording the signal with the at least one seismic sensor; evaluating a frequency drift of the recorded signal; and determining a position of the at least one seismic sensor based on the evaluated frequency drift and a source movement relative to the at least one sensor.

Abstract: Method and catenary front-end gear for towing streamers under water. The catenary front-end gear includes a main cable configured to be attached to a vessel and a device; a connecting system configured to connect streamers to the main cable; and plural streamers. The main cable takes a catenary shape when towed by the first vessel underwater.

Abstract: Method and marine acoustic source array for generating an acoustic wave in a body of water. The marine acoustic source array includes a first depth sub-array set of first acoustic source points configured to be provided at a first depth (z1), the first acoustic source points having different inline first locations along a longitudinal axis (X); and a second depth sub-array set of second acoustic source points configured to be provided at a second depth (z2), the second acoustic source points having different inline second locations along the longitudinal axis (X). The first locations do not coincide along the longitudinal axis (X) with any of the second locations.

Abstract: Computer instructions, computing device and method for processing seismic data under-sampled in an angle domain, the seismic data corresponding to a reverse time migration, three-dimensional, angle domain common image gather (ADCIG). The method includes receiving the seismic data; calculating, based on the seismic data, shot and receiver wave-fields with an RTM wave propagation engine; applying a wave-fields decomposition algorithm to obtain a propagation direction for the shot and receiver wave-fields; forming the ADCIG by applying an image condition to the shot and receiver wave-fields; determining that specular energies of the ADCIG are under-sampled around a reflection angle; during the step of forming the ADCIG, extrapolating the specular energies to a neighborhood of the reflection angle; and generating an image of a subsurface that is being surveyed based on the extrapolated specular energies.

Abstract: Method and an anti-attachment device configured to be provided on a streamer. The anti-attachment device includes a body configured to be provided around the streamer and a first end is configured to be rotatably attached to the streamer.

Abstract: A computing device, computing medium and method for generating an image of a tilted orthorhombic medium. The method includes receiving seismic data related to the tilted orthorhombic medium; calculating a wave propagation with a processing device by applying a second-order equation for reverse time migration to the seismic data to generate a tilted orthorhombic wave propagation; and generating the image of the tilted orthorhombic medium based on the tilted orthorhombic wave propagation.

Abstract: Method and an array of streamers that prevent/slow down marine animals to attach to the streamers. The array includes at least one streamer including plural sections; and a net provided over at least one section of the at least one streamer.

Abstract: The invention concerns a method to acquire seismic waves by means of a streamer towed by a vessel and comprising a plurality of seismic receivers. The streamer comprises a head portion that is slanted relative to the water surface and a tail portion having at least one section with a different slant.

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.