Abstract: A marine seismic source includes source elements configured to emit waves having different frequencies while the source elements are towed at different predetermined depths, respectively. The predetermined depths are calculated such that water-surface reflections of the waves generated by a source element among the source elements interfere constructively with the waves generated by the source element and propagating toward an explored structure under the seafloor. The waves combine to yield a spike-like signature of the source.

Abstract: Methods and systems for processing data acquired using a variable-depth streamer, obtain up-going and down-going wavefields at a predetermined datum, and use them to identify multiples included in the up-going wavefield. An image of a geological formation under the seabed is then generated using the data from which the multiples have been removed, and/or the multiples.

Abstract: Methods and systems for processing data acquired using a variable-depth streamer, obtain up-going and down-going wavefields at a predetermined datum, and use them to identify multiples included in the up-going wavefield. An image of a geological formation under the seabed is then generated using the data from which the multiples have been removed, and/or the multiples.

Abstract: Seismic survey system and method for adjusting positions of plural autonomous receiver nodes (ARNs) of a seismic survey system. The method includes calculating first travel-times of direct arrivals of seismic waves, based on (i) offsets between shooting positions of seismic sources and recording positions of the plural ARNs, and (ii) a speed of the seismic waves in water; estimating second travel-times of the direct arrivals, based on seismic data recorded by the plural ARNs; estimating, in a computing device, positioning errors of one or more of the plural ARNs by applying an inversion algorithm to a misfit between the first and second travel-times; and adjusting the recording positions of the one or more ARNs with the positioning errors.

Abstract: Computing device, computer instructions and method for processing energy at a free-surface reflection relating to an air-water interface. The method includes receiving input seismic data recorded with seismic sensors; receiving wave-height data that describes an actual shape of a top surface of a body of water; processing up-going energy at a receiver and down-going energy following a reflection at the sea-surface, using the input seismic data and a linear operator modified to take into account the wave-height data; and generating an image of the subsurface based on the up-going energy or the down-going energy or a combination of the input seismic data and one of the up-going or down-going energy.

Abstract: Computing device, computer instructions and method for processing input seismic data d. The method includes receiving the input seismic data d recorded in a data domain, solving a linear inversion problem constrained by input seismic data d to obtain a model domain and its energy, wherein the linear inversion problem is dependent on sparseness weights that are simultaneously a function of both time and frequency, reverse transforming the model domain energy to the data domain, and generating an image of a surveyed subsurface based on the reverse transformed model domain energy.

Abstract: Computing device, computer instructions and method for correcting an image, of a surveyed surface, due to a free-surface reflection. The method includes calculating a free surface reflection operator for a seismic source displaced in water based on a position of the source, and an air-water interface datum; receiving recorded seismic data d recorded with seismic sensors (r), wherein the recorded seismic data is associated with a pressure and/or a particle motion produced by a seismic wave in earth; correcting the recorded seismic data d based on the free surface reflection operator to obtain transformed seismic data; and generating an image of the surveyed subsurface, based on the transformed seismic data, wherein the image is indicative of various layers of the earth. The free surface reflection operator varies while a source signal is being emitted by the source.

Abstract: Generating spectrally enhanced seismic data expresses seismic data as a convolution of reflectivity and a seismic source wavelet. This seismic source wavelet varies over a sampling interval and defining a total amount of energy over the sampling interval. An enhanced seismic source wavelet that is a single-valued energy spike that yields the total amount of energy over the sampling interval is generated. In addition, the reflectivity is modified to preserve amplitude variation with angle. The reflectivity is convoluted with the enhanced seismic source wavelet and residual energy is added to the convolution to generate the spectrally enhanced seismic data.

Abstract: Methods and apparatuses for directional designature in shot domain are provided. Azimuth and take-off angles are calculated for each record in the seismic data. Directional designature is then applied to the seismic data using a source signature dependent on the azimuth and take-off angles.

Abstract: During seismic data acquisition the seismic sources and/or seismic receivers are deployed according to an irregular arrangement departing in a predetermined manner from repetitive spatial patterns formed by or within groups of adjacent among the seismic sources or adjacent among the receivers. Additionally or alternatively, source activation moments of the sources within a series of source firing time intervals are determined using Golomb ruler sequences or a non-linear inversion.

Abstract: Computing device, computer instructions and method for calculating an image of a subsurface based on least square migration and image de-convolution using a matching operator F. The method includes receiving seismic data d; computing a first image m of the subsurface based on the seismic data d; computing a second image h of the subsurface based on the first image m; applying a transform operation to the first and second images m and h to obtain a first transform of the first image and a second transform of the second image; calculating the matching operator F by matching the first transform of the first image to the second transform of the second image; and generating an updated image mupdated of the subsurface based on the matching operator F and the first transform of the first image.

Abstract: Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method may include receiving input seismic data recorded by seismic receivers that located at different depths (zr), generating migration data (du) and mirror migration data (dd) from the input seismic data, deriving a ghost free model (m) based on simultaneously using the migration data (du) and mirror migration data (dd), generating primary (p) and ghost (g) datasets based on the ghost free model (m), simultaneously adaptively subtracting the primary (p) and ghost (g) datasets from the migration data (du) to provide adapted primary (p?1 and p?2) and adapted residual (r?1 and r?2) datasets and generating a final image (f) of the subsurface based on the adapted primary (p?1 and p?2) and the adapted residual (r?1 and r?2) datasets.

Abstract: Computing device, computer instructions and method for up-down separation of seismic data. The method includes receiving the seismic data, which includes hydrophone data and particle motion data; performing a first up-down separation, which is independent of a ghost model, using as input the hydrophone data and the particle motion data, to obtain first up-down separated data; performing a second up-down separation by using as input a combination of (i) the hydrophone data and/or the particle motion data and (ii) the first up-down separated data, wherein an output of the second up-down separation is second up-down separated data; and generating an image of the subsurface based on the second up-down separated data.

Abstract: A method for processing seismic data includes receiving seismic data and a velocity model (c(x)) for a plurality of locations (x), scaling a dimension of the seismic data according to the velocity model (c(x)) to provide a velocity normalized seismic data, and generating a final image (S(x)) of the subsurface using the velocity normalized seismic data. The velocity normalized seismic data may be a reverse-time migration image (I(x,?)) corresponding to the plurality of locations (x) and a plurality of propagation distance offsets (?). The method may also include transforming the reverse-time migration image (I(x,?)) for the plurality of selected positions (x) to a wavenumber domain to provide velocity normalized wavenumber data (I(k,?)) and suppressing data components corresponding to non-physical or undefined reflection angles to provide enhanced wavenumber data (I?(k,?)) and using the enhanced wavenumber data (I?(k,?)) to generate the final image (S(x)). A corresponding apparatus is also disclosed herein.

Abstract: Data is recorded by sensors while an underground formation is explored, e.g., using a seismic acquisition system that emits and receives waves. A model, which is indicative of primary waves contained in the received data, is derived using a multi-order Green's function. Using the model, an image of the underground formation is generated.

Abstract: A method for removing ocean bottom and/or geology related contamination. The method includes receiving first measurements corresponding to first seismic sensors mounted on a first source array; receiving second measurements corresponding to second seismic sensors mounted away from the first source array; processing the second measurements to determine a contamination model related to the ocean bottom and geology; removing the contamination model from the first measurements to obtain cleaned data; and calculating a source signature of the first source array based on the cleaned data.

Abstract: A device, medium and method for deblending seismic data associated with a subsurface of the earth. The method includes receiving an input dataset generated by first and second sources S1 and S2 that are operating as simultaneous sources; arranging the input dataset based on the firing times of source S1; applying with a computing system an annihilation filter to the arranged input dataset to estimate cross-talk noise; convolving the cross-talk noise estimate with an operator to form a signal estimate using the firing times of S1 and S2; and generating an image of the subsurface based on the signal estimate.

Abstract: Computing device, computer instructions and method for processing input seismic data d. The method includes a step of receiving the input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including up-going and down-going wave-fields; a step of generating a model p in a second domain to describe the input seismic data d; and a step of processing with a processor the model p to obtain an output seismic dataset indicative of the down-going wave-field and substantially free of the up-going wave-field.

Abstract: Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method may include receiving input seismic data recorded by seismic receivers that located at different depths (zr), generating migration data (du) and mirror migration data (dd) from the input seismic data, deriving a ghost free model (m) based on simultaneously using the migration data (du) and mirror migration data (dd), generating primary (p) and ghost (g) datasets based on the ghost free model (m), simultaneously adaptively subtracting the primary (p) and ghost (g) datasets from the migration data (du) to provide adapted primary (p?1 and p?2) and adapted residual (r?1 and r?2) datasets and generating a final image (f) of the subsurface based on the adapted primary (p?1 and p?2) and the adapted residual (r?1 and r?2) datasets.

Abstract: Computing device, computer instructions and method for processing input seismic data d. The method includes a step of receiving the input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including up-going and down-going wave-fields; a step of generating a model p in a second domain to describe the input seismic data d; and a step of processing with a processor the model p to obtain an output seismic dataset indicative of the down-going wave-field and substantially free of the up-going wave-field.