A method of redatuming geophysical data, wherein there is provided multi-component geophysical data, and the method includes obtaining at least one focussing function and/or at least one Green's function from the multi-component geophysical data.

A method for obtaining zero-offset and near zero offset seismic data from a marine survey, with separation of direct arrival information and reflectivity information, the method including: modeling a direct arrival estimate at a passive near-field hydrophone array by using a notional source separation on active near-field hydrophone data; generating reflection data for the passive near-field hydrophone array by subtraction of the modeled direct wave from data recorded by the passive near-field hydrophone array; generating near zero-offset reflectivity traces by stacking the reflection data for the passive near-field hydrophone array on a string-by-string basis or on a combination of strings basis; generating reflectivity information at the active near-field hydrophone array by subtracting the direct arrival estimate modeled using the notional source separation from the active near-field hydrophone data; and generating an estimate of zero-offset reflectivity traces by calculating a cross-correlation between the between the reflectivity information at the active near-field hydrophone array and the near zero-offset traces and performing an optimized stacking with summation weights based on coefficients of the cross-correlation.

Provided is a method for swell effect and mis-tie correction in high-resolution marine seismic data using multi-beam echo sounder data, and more particularly, a method for swell effect and mis-tie correction in high-resolution marine seismic data using multi-beam echo sounder data capable of acquiring the high-resolution marine seismic data having the swell effect and the mis-tie effectively corrected by using the multi-beam echo sounder data including water depth data of a sea-bottom having high precision.

Method for optimal stacking of seismic images to remove noise and enhance signals in seismic images (101) outputted from a Reverse Time Migration (RTM) imaging process. Dip information is calculated (102) and then sorted by image point (104), for each seismic image to be stacked. A dominant dip and azimuth is determined at each image point (106), and only those events are stacked (107). If the image is still noisy or lacking in detail (108), the process may be iterated (109) to improve the selection of most likely dip and azimuth.

Leveraging migration and demigration, here we propose a learning-based approach for fast denoising with applications to fast-track processing. The method is designed to directly work on raw data without separating each noise type and character. The automatic attenuation of noise is attained by performing migration/demigration guided sparse inversion. By discussing examples from a Permian Basin dataset with very challenging noise issues, we attest the feasibility of this learning-based approach as a fast turnaround alternative to conventional denoising methodology.

Methods for full waveform inversion (FWI) in the midpoint-offset domain include using a computer system to sort seismic traces into common midpoint-offset bins (XYO bins). For each XYO bin, a linear moveout correction is applied to a collection of seismic traces within the XYO bin. The collection of seismic traces is stacked to form a pilot trace. The computer system determines a surface-consistent residual static correction for each seismic trace. The computer system determines that the surface-consistent residual static correction for each seismic trace is less than a threshold. Responsive to the determining that the surface-consistent residual static correction is less than the threshold, the computer system stacks the collection of seismic traces to provide the pilot trace. The computer system groups the pilot traces for the XYO bins into a set of virtual shot gathers. The computer system performs one-dimensional FWI based on each virtual shot gather.

A method and a system for implementing the method are disclosed wherein the source wavelet, input parameter models, and seismic input data may be obtained from a non-flat surface, sometimes mild, or foothill topography as well as the shot and receiver lines might not necessarily be straight, and often curve to avoid obstacles on the land surface. In particular, the method and system disclosed, suppresses low wavenumber and low frequency noises, by balancing lateral and vertical amplitudes to produce an image of subsurface reflectors located within a survey area having higher lateral resolutions and wavenumbers, as well as higher high-cut frequencies, and lower low-cut frequencies in complex media, than could otherwise not be achieved by other methods commonly known in the art.

A data optimization method and an integral prestack depth migration method are provided, including acquiring a target matrix to be optimized; generating a first sequence according to the target matrix; rarefying the first sequence according to a preset grid density to obtain a value position of each element of a second sequence, and working out a value of each element of the second sequence on the basis of the principle of least squares; performing interpolation on the second sequence to obtain a third sequence; calculating a target matrix corresponding to the third sequence; calculating an error between the target matrix to be optimized and the target matrix corresponding to the third sequence; recording, when the error is less than the first error threshold, the target matrix corresponding to the above second sequence as an optimized target matrix of the target matrix to be optimized.

The present disclosure concerns a computer implemented method for correcting a reservoir model comprising a stratigraphic grid modeling a reservoir geological formation. The method includes obtaining a 3D image representing values of a physical property obtained from seismic measurements performed on the reservoir geological formation. A skeleton is calculated for the values of the physical property of the 3D image. Each point of the skeleton is associated to a respective cell of the stratigraphic grid. One reference layer is determined for at least one set of points of the skeleton. For each point of the at least one set, a layer gap is calculated between the reference layer and the cell associated to said point, and the reservoir model is corrected based on the layer gaps.

A system provides seismic images of the subsurface by enhancing pre-stack seismic data. The system obtains seismic data comprising a plurality of seismic traces that are generated by measuring reflections of seismic waves emitted into a geological formation. The system sorts seismic data into at least one multidimensional gather comprising a data domain. The system determines local kinematical attributes of a seismic trace. The system forms an ensemble of seismic traces, each representing a reference point. The system applies local moveout corrections to each seismic trace of the ensemble. The system applies residual statics and phase corrections for each seismic trace that is corrected by the local moveout corrections. The system sums the seismic traces of the ensemble to obtain an output seismic trace having an increased signal-to-noise ratio (SNR) relative to the seismic trace that represents the reference point for the ensemble of seismic traces.