Abstract: Methods and systems for generating a stable reverse time demigration (RTDM) equation for predicting wave phenomena such as reflections, refractions and multiples are described. A coupling term is added to an RTDM equation and reflectivity associated with the coupling term is replaced with a pseudo-density function derived from a nonlinear equation. The resultant coupled and stabilized RTDM equation is then used to predict the desired wave phenomena based on the applied seismic image.

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, wherein the first and second seismic data are recorded at the same locations underwater; calculating with a processor models of the first and second seismic data in a transform domain that is different from the time-space domain; performing a wavefield separation using the first and second datasets in the transform domain; determining a noise in the transform domain corresponding to the second seismic data based on the wavefield separation; 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: Computing device, computer instructions and method for de-ghosting seismic data related to a subsurface. 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. In certain embodiments, the input seismic data d includes both hydrophone data and particle motion data.

Abstract: Methods and systems for optimized receiver-based ghost filter generation are described. The optimized ghost filter self-determines its parameters based on an iterative calculation of recorded data transformed from a time-space domain to a Tau-P domain. An initial ghost filter prediction is made based on generating mirror data from the recorded data and using a least squares technique during a premigration stage.

Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data (g) generated by actuating the one or more land seismic source with a single sweep; selecting a number of detectors (a-f) that detect a subset (ga-gf) of the seismic data (g); estimating earth responses (ha1-hf1) based on (i) the subset seismic data (ga-gf) and (ii) a ground force (gf) of the one or more land seismic source; calculating plural intermodulation noises (noiseA1-noiseF1) for the number of detectors based on the earth responses (ha1-hf1); and removing the plural intermodulation noises (noiseA1-noiseF1) from corresponding detector signals (ga-gf) to mitigate the intermodulation noise effect.

Abstract: A system for collecting seismic data includes plural seismic sensors. The seismic sensors are buried underground. In one application, a first set of seismic sensors are buried at a first depth and a second set of seismic sensors are buried at a second depth. In another application, the sensors alternate along a line, one sensor from the first set and a next sensor from a second set. In still another application, the sensors are randomly distributed below the ground.

Abstract: A cleaning device for cleaning a marine element towed in water and related methods are provided. The cleaning device includes a body configured to enclose the marine element; at least one wing attached to the body and configured to impart translational and rotational motion to the body when interacting with the water; a switching and locking mechanism configured to change an orientation of the at least one wing between a first orientation and a second orientation when contacting a stopper and also to lock the selected orientation; rotating means attached to an internal surface of the body and configured to contact the marine element, the rotating means having axles that make a fix angle with a longitudinal axis of the body; and a cleaning tool attached to the body and configured to clean the marine element.

Abstract: A seismic survey system records seismic signals during a marine seismic survey. The system includes first and second clusters, each including a set of autonomous underwater vehicles (AUVs); each cluster being associated with a corresponding first or second unmanned surface vehicle (USV); and a central control unit located on a floating platform and configured to control the first and second USVs. The first USV follows its own path and the first cluster follows the first USV independent of the second USV or the second cluster.

Abstract: Location of underwater moving target device carrying a receiver configured to detect acoustic waves emitted at a known location is estimated such that to be consistent with detected velocity and orientation of the target device, and with a current phase of a signal corresponding to the acoustic waves detected at the target device. A stack including one or more boxes obtained by applying contractors to location boxes is output as the estimate of the location of the moving target device.

Abstract: A method for calculating intermodulation noise generated with one or more land seismic sources. The method includes receiving seismic data generated by actuating the one or more land seismic source with a first sweep and a second sweep; calculating with a computing device a first earth response corresponding to the first sweep; calculating with the computing device a second earth response corresponding to the second sweep; and calculating the intermodulation noise based on the first and second earth responses. The second sweep is a time reverse sweep of the first sweep.

Abstract: Wide azimuth data acquisition systems using at least three streamer sets achieve shorter survey time and enhanced angular coverage relative to conventional systems using two streamer sets. Various techniques such as high-density seismic source activation and alternating surveyed bands with skipped bands lead to data quality similar to the conventional system, while maintaining the increased productivity advantage.

Abstract: A method for detecting faults of individual wave sources in a marine source array includes acquiring near-field data using sensors, the sensors being located near the individual wave sources. The method further includes generating an index for each of the individual wave sources based on (A) the near-field data and (B) information on the geometry of the marine source array that enables localizing the individual wave sources and respective sensors relative to one another. The method also includes comparing the index for each of the individual wave sources with a corresponding reference index for determining whether a fault has occurred.

Abstract: The present disclosure includes a method for suppressing 4D noise. The method includes calculating a first similarity map based on the similarity of one of one or more first 3D images and a second 3D image. The first and second 3D images are derived from first and second surveys, respectively. The method also includes calculating a second similarity map based on the similarity of one of the one or more first 3D images and a third 3D image, which is derived from the second survey. The method also includes calculating a third similarity map based on the similarity of first and second 4D images, which are based on differences between the 3D images. The method also includes generating a composite 4D image based at least on the first, second, and third similarity maps. The present disclosure may also include associated systems and apparatus.

Abstract: Computing device, computer instructions and method for directional designature of seismic data d with a given source directivity. The method includes obtaining directional operators r; calculating a model u with a modified source directivity based on (1) seismic data d, and (2) an operator that is a combination of the directional operators r and a reverse transform operator L; using the model u to obtain seismic data dfree with modified source directivity; and generating a final image of the subsurface using seismic data dfree.

Abstract: Method and device for generating an induced source shot point gather. The method includes receiving seismic data at least partially generated by an unintentional seismic source; calculating plural reconstructed receiver traces (RGi) based on pairing traces from the seismic data; and generating the induced source shot point gather based on the plural reconstructed receiver traces (RGi).

Abstract: A marine node for recording seismic waves underwater. The node includes a main body having a torus shape; a central body provided inside a space defined by the main body and connected to the main body through at least a link; a first thruster provided in the main body and configured to propel the main body along a central axis (Z) of the main body; and a seismic sensor configured to record the seismic waves underwater.

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.

Abstract: Methods of compensating for source signature effects in seismic data are described. One method includes a step of receiving seismic data recorded with a receiver; a step of receiving source data of the seismic waves generated by the moving source; a step of receiving position data of the source while generating the seismic waves; a step of determining a transform operator using the source data, the position data, and a selected domain-transform operator; a step of determining a seismic model by mathematically optimizing a relationship between the transform and the seismic data; and a step of compensating for the source signature effects in the seismic data using the seismic model. A method for generating an image of a subsurface of a geographical area using seismic data includes compensating the seismic data for source signature effects using a model which assumes a moving, non-impulsive source.

Abstract: Various methods preserve or restore the low roughness throughout an outer shell of a device (e.g., a streamer) used underwater for seismic surveys, by applying various substances that fill micro-cracks, are easy to polish or are self-healing. Apparatuses used to implement these methods may be used shortly before the devices are deployed in water, for example, having the device passing through such an apparatus as it is moved to be deployed in water.

Abstract: A cleaning device for cleaning a marine element towed in water and related methods are provided. The cleaning device includes a body configured to enclose a marine element; at least one wing fixedly attached to the body and configured to impart translational motion to the body when flowing in water; and a keel attached to the body and configured to limit a rotation of the body. The at least one wing is oriented relative to the body so that the cleaning device travels from a head portion toward a tail portion of the marine element when the marine element is towed at an angle less than a triggering angle with a traveling direction of a vessel towing the marine element.