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.

According to one embodiment, a near-field data is used to determine a taper length that can isolate the source signature at the top of near-field data with minimum interaction with the Green's function. In some embodiments, a range of taper lengths is selected and for each length after tapering the near-filed data, converting each filtered near-field data to its minimum-phase equivalents. Summing pairwise cross-correlation of all of the minimum-phase equivalent wavelets at the zero-lag provides an attribute that shows how much the tapered portions of the near-field data look alike. An acceptable taper size will be the one that has the highest summation value. Finally, the average of the minimum-phase equivalents of tapered near-field data with the selected taper size is the estimated source signature.

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.

Post-stack seismic data is received. Transformed seismic data is created from the received post-stack seismic data, including performing a super-resolution radon transform on the post-stack seismic data. Signal and noise regions are separated using the transformed seismic data, including using a defined muting function to remove unwanted noise. An inverse radon transform is performed using the separated signal and noise regions, outputting only signals.

A method, apparatus, and program product analyze time-series data such as seismic data collected from a subsurface formation by splitting a time-series data set such as an individual seismic trace into a plurality of spectral components, each having an associated frequency, determining an instantaneous frequency for each spectral component, determining a frequency difference for each spectral component based at least in part on the associated and instantaneous frequencies therefor, and determining a tuning parameter based at least in part on the determined frequency difference of each spectral component. Doing so enables, for example, thin-bed structures in the subsurface formation to be identified, and in some instances, thicknesses of such structures to be determined.

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.

A method, including: obtaining a scale-depth or scale-time phase image of a continuous wavelet transform of an input signal, the scale-depth or scale-time phase image including oval-shaped circular patterns observed on the mirrored phase image; and extracting, with a computer, hierarchical multiscale intervals from the scale-depth or scale-time phase image, wherein the hierarchical multiscale intervals correspond to the oval-shaped circular patterns observed on the mirrored scale-depth or scale-time phase image of the continuous wavelet transform of the input signal. Another method includes: characterizing, with a computer, curve shapes of intervals of a signal using beta distribution; and visualizing and analyzing, with the computer, shape parameters of the curve shapes on a shape-parameter crossplot.

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.

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.

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.