A method for de-blending seismic data associated with an interface located in a subsurface of the earth, includes receiving blended seismic data E generated by firing N source arrays according to a pre-determined sequence Seq; selecting N sub-datasets SDn from the blended seismic data E; interpolating each selected sub-dataset SDn to reference positions ref, where the blended seismic data E is expected to be recorded, to generate interpolated data k; de-blending, in a processor, the interpolated data k to generate de-blended data o; and generating an image of the interface of the subsurface based on the de-blended data o.

A method for echo detection may comprise recording one or more reflected waveforms, segmenting the one or more reflected waveforms based at least in part on a firing pulse length, applying a shaped filter to each segment of the one or more reflected waveforms, decoupling the one or more reflected waveforms into a time-frequency energy map, extracting a firing frequency band time domain plot from the decoupled time-frequency map, identifying a maximum amplitude in the extracted firing frequency band of the one or more reflected waveforms as an excitation, and identifying a second maximum amplitude in the extracted firing frequency band of the one or more reflected waveforms as an echo. A system for echo detection may comprise a digital signal processor, a transmitter, a transducer, a receiver, an analog to digital converter configured to digitize the measurement, and an information handling system.

The invention relates to continuously or near continuously acquiring seismic data where at least one pulse-type source is fired in a distinctive sequence to create a series of pulses and to create a continuous or near continuous rumble. In a preferred embodiment, a number of pulse-type seismic sources are arranged in an array and are fired in a distinctive loop of composite pulses where the returning wavefield is source separable based on the distinctive composite pulses. Firing the pulse-type sources creates an identifiable loop of identifiable composite pulses so that two or more marine seismic acquisition systems with pulse-type seismic sources can acquire seismic data concurrently, continuously or near continuously and the peak energy delivered into the water will be less, which will reduce the irritation of seismic data acquisition to marine life.

A computer-implemented method includes the following. A frequency sweep using sweep parameters is emitted from a vibratory seismic source into geological layers. The sweep parameters include frequencies and modulation parameters for seismic waves. Signals are received from one or more sensors. The signals include seismic data acquisition information, including values identifying energy reflected back from boundaries where rock properties change. A determination is made regarding which of the reflected seismic waves are attenuated. The determination uses an integral transform and a thresholding algorithm for image segmentation. Optimum sweep parameters are determined based on the reflected seismic values that are attenuated and updated to compensate for local geology effects. The emitting, receiving, determining attenuation, determining optimum parameters, and updating are repeated until the received signals are determined to be satisfactory.

Methods of geophysical modeling and inversion are disclosed. A sparse domain is defined for a geophysical model, over which a sparse model result is computed. A full model result is then resolved by interpolation over the sparse domain. The full model result may be used as the forward modeling result in a geophysical inversion process. Reconstruction error, or model error, or both may be used to adjust the sparse domain, the model, or the geophysical basis of the model.

Processes and systems described herein are directed to performing marine surveys with marine vibrators that emit orthogonal coded pseudo-random sweeps. In one aspect, coded pseudo-random signals are generated based on coded pseudo-random sequences. The coded pseudo-random sequences are used to activate the marine vibrators in a body of water above a subterranean formation. The activated marine vibrators generate orthogonal coded pseudo-random sweeps. A wavefield emitted from the subterranean formation in response to the orthogonal coded pseudo-random sweeps is detected at receivers located in a body of water. Seismic signals generated by the receivers may be cross-correlated with a signature of one of the orthogonal coded pseudo-random sweeps to obtain seismic data with incoherent residual noise.

A system to detect and control noise in seismic surveys is provided. The system receives, responsive to a seismic wave generated by a source, seismic data detected by a sensor component of a seismic data acquisition unit. The system generates, for windows of the seismic data, Hough tensors for seismic data transforms in multiple dimensions. The system detects, based on a comparison of an eigenvector and eigenvalue of a canonical matrix of the Hough tensors with a historical eigenvector and eigenvalue of a historical canonical matrix of historical Hough tensors of historical seismic data, a first presence of noise in the seismic data. The first presence of noise can correspond to a noisy spectra pattern in a seismic data transform of the seismic data. The system provides, responsive to detection of the first presence of noise in the seismic data, a notification to adjust a characteristic of the seismic survey.

Method for source localization for cable cut prevention using distributed fiber optic sensing (DFOS)/distributed acoustic sensing (DAS) is described that is robust/immune to underground propagation speed uncertainty. The method estimates the location of a vibration source while considering any uncertainty of vibration propagation speed and formulates the localization as an optimization problem, and both location of the sources and the propagation speed are treated as unknown. This advantageously enables our method to adapt to variances of the velocity and produce a better generalized performance with respect to environmental changes experienced in the field. Our method operates using a DFOS system and AI techniques as an integrated solution for vibration source localization along an entire optical sensor fiber cable route and process real-time DFOS data and extract features that are related to a location of a source of vibrations that may threaten optical fiber facilities.

Methods and systems for estimating converted-wave statics are disclosed. The methods include obtaining a multicomponent seismic dataset for a subterranean region, determining an array of PP-source statics and an array of PP-receiver statics for the PP-seismic dataset, generating a PP-receiver stack based on the PP-seismic dataset, the array of PP-source statics, and the array of PP-receiver statics, and generating a PS-receiver stack based on the PS-seismic dataset and the array of PP-source statics. The methods also include identifying a PP-target event on the PP-receiver stack, forming a space-time window of the PS-receiver stack guided by the PP-target event, determining an objective function, and determining an array of PS-receiver statics based on an extremum of the objective function. The methods further include forming a statics-corrected PS-seismic dataset based on the array of PS-receiver statics and the array of PP-source statics, and forming a seismic image based on the statics-corrected PS-seismic dataset.

Methods for processing seismic data acquired with non-impulsive moving sources are provided. Some methods remove cross-talk noise from the seismic data using emitted signal data and an underground formation's response estimate, which may be iteratively enhanced. Some methods perform resampling before a spatial or a spatio-temporal inversion. Some methods compensate for source's motion during the inversion, and/or are usable for multiple independently moving sources.