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: A method for deghosting seismic data collected with a seismic system, the seismic data being related to a subsurface of a body of water. The method includes receiving the seismic data recorded by detectors distributed along a variable-depth profile; calculating migrated (d1) and mirror-migrated (d2) gathers based on the seismic data, wherein the migrated and mirror-migrated gathers depend on a feature characterizing a configuration of the seismic system; applying a joint deconvolution model to the migrated and mirror-migrated gathers (d1, d2) to calculate a single deghosted gather (dg); and generating a final image of the subsurface based on the single deghosted gather (dg). The feature is not present in a gather after a step of stacking that is performed prior to generating the final image.

Abstract: A system and method are described herein for generating a frequency sweep signal set for use in seismic data gathering. Low frequency sweep rate modifications are combined to compensate for vibrator limitations and vibrator far-field responses with high frequency sweep rate modifications to compensate for absorption, and then the frequency sweep signal set is generated based on the combination of high and low frequency sweep rate modifications.

Abstract: A method and a catenary seismic source steering gear for towing seismic sources underwater. The catenary gear includes plural seismic sources configured to generate seismic waves underwater; a main rope configured to span between first and second vessels; and a connecting system configured to connect the plural seismic sources to the main rope. The main rope takes a substantially catenary shape when towed by the first and second vessels underwater.

Abstract: Method and retrievable vertical hydrophone cable for collecting seismic data underground. The retrievable vertical hydrophone cable includes an envelope having a first end at which a connector mechanism is provided to close the envelope; plural hydrophones distributed inside the envelope at predetermined positions; and a fluid provided inside the envelope and around the plural hydrophones. The envelope increases its volume when the fluid is pressurized through the connector mechanism.

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: Methods and systems for a surface-consistent amplitude and deconvolution simultaneous joined inversion are described. A one-pass estimation using input trace data for generating gain and deconvolution operator based on a least squares iteration method. A series of iterations are performed simultaneously and independently estimating amplitude scalars and autocorrelation spectra with a common convergence criterion. The gain and deconvolution operator can further be used to correct the input trace data for pre-stack or stack imaging.

Abstract: Methods and systems for improving azimuth distribution in a seismic acquisition system are described. A survey acquisition system includes a plurality of streamers towed by a plurality of streamer vessels, including a first streamer vessel and a second streamer vessel and a plurality of sources towed by a plurality of source vessels. The plurality of streamer vessels and plurality of source vessels are configured relative to one another such that the plurality of source vessels are positioned at one or more predetermined inline distances behind a portion of the first streamer vessel and are also positioned at one or more predetermined inline distances in front of a portion of the second streamer vessel. The plurality of streamer vessels and plurality of source vessels are also spaced apart from one another in a cross-line direction.

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: A cleaning device for cleaning a marine streamer towed underwater and related methods are provided. The cleaning device includes a housing configured to be attached to the streamer, a motor mounted inside the housing, a propeller configured be rotated by the motor and to drive the housing along and relative to the streamer in a towing direction, and a controller configured to control the motor and the propeller.

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: A method, an apparatus and a computer readable medium for generating an image of a subsurface based on seismic data corresponding to at least two different times, for a same surveyed area are provided. A cost function, which is a sum over the seismic data vintages of a norm of differences between data and model predicted multiples, is minimized subject to minimizing residual multiples that are differences of corresponding multiples belonging to different vintages among the seismic data vintages.

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: 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: Deflectors configured to be attached to cables towed behind a vessel for performing a marine survey are provided. A deflector has a wing body including a first part joined to a second part to form a swept-back-wing shape, the first part and the second part being substantially coplanar. A first straight line stretching along at least a portion of a front edge of the first part makes a first angle with a second straight line stretching along at least a portion of a front edge of the second part. A third straight line stretching along at least a portion of a trailing edge of the first part makes a second angle with a fourth straight line stretching along at least a portion of a trailing edge of the second part, the first angle and the second angle being non-zero angles.

Abstract: Computing device and method for calculating time-shifts associated with travel-times of seismic waves emitted by a source and recorded by plural seismic detectors after reflection from a subsurface structure. The method includes receiving seismic data (d) that includes plural traces related to a subsurface, wherein the seismic data (d) is in a time-space domain; transforming with a processor the seismic data (d) from the time-space domain to a radon domain; picking linear events from the seismic data in the radon domain; calculating the time-shifts associated with the picked linear events; correcting the seismic data (d) based on the time-shifts to obtain new seismic data (d?); and computing an image of the subsurface based on the new seismic data (d?). The time-shifts are calculated per trace and per event.

Abstract: A method for processing seismic data including contiguous-sweep records corresponding to rotated sweep segments includes attenuating harmonics and generating stacked traces, each stacked trace being a weighted sum of traces corresponding to same location in the subsurface, based on seismic data from different seismic receivers, following plural shots at plural locations.

Abstract: Computing device, computer instructions and method for denoising marine seismic data recorded with first and second seismic sensors. The method includes receiving first seismic data recorded with the first sensor in a time-space domain; receiving second seismic data recorded with the second sensor in the time-space domain, calculating with a processor models of the first and second seismic data in a transform domain that is different from the time-space domain; calculating in the transform domain an energy related to a down-going energy based on the models of the first and second seismic data; determining a noise in the transform domain corresponding to the second seismic data based on the calculated energy; reverse transforming the noise from the transform domain into the time-space domain; and denoising the second seismic data by subtracting the noise in the time-space domain from the second seismic data.

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: Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes receiving seismic data recorded by seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain; modeling the seismic data in a shot or common midpoint domain as a function of operators to derive a model; using the derived model to remove the receiver ghost from the seismic data to obtain deghosted seismic data; and generating a final image of the subsurface based on the deghosted seismic data.