Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Recorded data may be aligned to a primary source. A deblending procedure may be iteratively applied to produce a residual term and deblended estimates for the primary source and one or more secondary sources. Following an iteration of the deblending procedure, the resultant data may be sorted according to a domain that renders the one or more secondary sources incoherent with respect to the primary source. The domain used for sorting may be different from a domain used to sort during an immediately prior iteration. In embodiments, the deblending procedure may use coherency filtering, and the coherency filtering may be weighted according to a signal-to-noise metric generated from the data being deblended.

Techniques to reduce noise in seismic data by receiving a set of seismic data comprising a plurality of input volumes each inclusive of positional data and at least one additional attribute related to the seismic data, selecting a first input volume of the plurality of input volumes having a first additional attribute related to the seismic data, and generating a pilot volume by selecting a range of input volumes of the plurality of input volumes and stacking input volumes of the range of input volumes with the first input volume. Additionally, generating a trained dictionary based upon transformation of the pilot volume, transforming the first input volume into transformed data, imposing a sparse condition on the transformed data utilizing the trained dictionary to generate sparsified data, and inverse transforming the sparsified data to generate an output data volume as a portion of a set of modified seismic data.

Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Multiple sets of deblended receiver traces are generated by iteratively applying a coherency filter to estimated sets of deblended receiver traces and updating a residual until a termination condition is reached. In some embodiments, applying the coherency filter during a current iteration may include determining coefficients of the coherency filter based on estimated sets of deblended receiver traces from an immediately prior iteration. In further embodiments, applying the coherency filter may include applying a 3D projection filter, such as an fxy projection filter.

Seismic data is deblended by performing, for each receiver, a first inversion and a second inversion in a transform domain. The first inversion is formulated to minimize a number of non-zero coefficients of the first inversion result. A sub-domain of the transform domain is defined by vectors of a transform domain basis for which the first inversion has yielded the non-zero coefficients. The second inversion is performed in this sub-domain. The solution of the second inversion is used to extract deblended seismic datasets corresponding to each of the distinct signals, from the seismic data.

Systems and methods for downhole signal filtering. A method for downhole signal filtering may comprise defining outliers as isolated values; providing thresholds; determining the outliers from a buffer; computing a difference in slowness between adjacent pairs of values; comparing the adjacent pairs of values to other values in a same window; determining if the adjacent pairs of values vary more than the threshold; assigning a 2D flag array a value of 0 if the adjacent pairs of values vary more than the threshold; and computing a 75% percentile distribution for each adjacent pair of values to determine if each adjacent pair of values are the outliers.

A method of low-frequency seismic data enhancement for improving the characterization precision of a deep carbonate reservoir includes: first performing inversions on an input seismic data set to obtain the corresponding reflection coefficients and average seismic wavelet; then constructing a seismic wavelet with rich low-frequency information; and finally, performing convolution on the seismic wavelet with rich low-frequency information and the reflection coefficients to obtain seismic data with rich low-frequency information and enhanced low-frequency energy. In the present invention, changes of the seismic data in a work area in transverse and longitudinal directions are taken into consideration, and processing parameters can be quickly determined according to actual conditions of the work area to obtain an optimal processing effect. In this way, the characterization quality of geological anomalies, such as a fault, a fracture system, or the like, in a deep carbonate reservoir can be improved significantly.

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.

The present disclosure relates to a method of processing seismic signals comprising: receiving a set of seismic signals, applying a wavelet transformation to the set of signals and generating transformed signals across a plurality of scales. Then for each scale determining coherence information indicative of the transformed signals and generating a comparison matrix comparing the transformed signals, then outputting seismic attribute information based on combined coherence information.

A method includes receiving, via a processor, a first seismic dataset generated using a first type of survey system. The method further includes receiving, via the processor, a second seismic dataset generated using a second type of survey system. The method additionally includes determining a frequency band in which to combine the first seismic dataset with the second seismic dataset to generate a combined dataset and generating a seismic image based upon the combined dataset, wherein the seismic image represents hydrocarbons in a subsurface region of the Earth or subsurface drilling hazards.

Some implementations of the present disclosure provide a method that include: accessing a set of seismic traces from a grid of locations inside an geo-exploration area, each seismic trace records seismic reflections from underneath the geo-exploration area at a location of the grid; accessing an input indicating a surface in the set of seismic traces; extracting a plurality of wavelets from the set of seismic traces, each wavelet covering an adjustable length around the surface; determining a reference wavelet for each wavelet of a corresponding adjustable length; and quantifying a quality of the surface based on correlating the plurality of wavelets with each reference wavelet of the corresponding adjustable length.