A method can include receiving data that includes signal data and coherent noise data where the signal data includes signal data that corresponds to a multidimensional physical structure; generating filtered data by filtering at least a portion of the data to attenuate at least a portion of the coherent noise data by applying a multidimensional geometric coherent noise model defined by at least one geometric parameter; and assessing a portion of the signal data in the generated filtered data to characterize the multidimensional physical structure.

Systems, methods, and apparatuses for generating a subsurface image using diffraction energy information are disclosed. The systems, methods, and apparatuses may include converting a shot gather into one or more plane-wave gather using a Radon transform. The plane-wave gathers may be extrapolated into source-side wavefields and receiver-side wavefields and further generate a pseudo dip-angle gather. The diffraction energy information may be extracted from the pseudo dip-angle gather, and an image containing subsurface features may be generated from the extracted diffraction energy information. The receiver-side wavefields may be decomposed using a recursive Radon transform.

Methods and systems for identifying a multiple artifact are disclosed. The method includes obtaining a post-stacked seismic image of a subterranean region and identifying a horizon with the post-stacked seismic image. The method further includes determining a spectral section over the horizon by applying spectral decomposition to the post-stacked seismic image. The method still further includes detecting a frequency anomaly within the spectral section by comparing the spectral section to a reference spectral section and identifying the multiple artifact based on the frequency anomaly.

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 disclosed technology provides solutions for identifying noise in seismic profile data sets. In some aspects, a process of the disclosed technology includes steps for receiving wellbore data including seismic measurements, processing the wellbore data to generate a seismic input image including visual representations of the one or more seismic measurements, and processing the seismic input image to identify a noise region in the seismic input image. Systems and machine-readable media are also provided.

A symmetry attribute is described that may be used for determining seismic stratigraphic features in a formation. In one example, seismic input data from a formation is processed to determine an attribute by selecting a center trace, assigning a first cluster of the traces to a left image and a second cluster of the traces to a right image, and determining symmetry about the center trace between the left and the right images.

The present invention is a method to determine an azimuthal orientation of a borehole seismometer sensor performed by a computing device using a control server having a database and an arithmetic function, the computing device performing a method to determine the azimuthal orientation of a borehole seismometer sensor using long-period surface waves in microseisms, including step S100 in which a data collection unit 100 collects continuous waveform data recorded by a borehole seismometer and a reference seismometer; step S200 in which a frequency band setting unit 200 sets a frequency band to be analyzed in the collected continuous waveform data; step S300 in which a filtering unit 300 performs bandpass filtering on the frequency band to be analyzed; step S400 in which a waveform dividing unit 400 divides seismic waveform into waveform segments with preset time units; step S500 in which a phase shift unit 500 shifts the phase of the divided vertical component waveforms by 90°; step S600 in which a waveform calculation unit 600 combines the divided N′ and E′ component seismic waveforms to calculate horizontal components for rotation angles waveform between 0 and 360° from the N′ orientation; step S700 in which a correlation calculation unit 700 calculates a correlation coefficient between the horizontal and vertical component waveforms; step S800 in which a Rayleigh wave orientation determination unit 800 repeats steps S500 to S700 for each divided time domain; step S900 in which an orientation comparison unit 900 performs steps S400 to S800, respectively, with respect to the borehole seismometer data for which the sensor orientation is to be determined and the reference seismometer data for which the sensor orientation is already known; and step S1000 in which a result calculation unit 1000 averages 0 determined for each time period to calculate a final result.

A method for determining an internal multiple attenuated seismic image is disclosed. The method includes obtaining a seismic dataset composed of a plurality of seismic traces and for each seismic trace determining an internal multiple trace based, at least in part, on a nested truncated correlation and a bounded convolution of the seismic trace with itself. The method further includes determining an internal multiple attenuated seismic trace based, at least in part, on subtracting the internal multiple trace from the seismic trace and combining the internal multiple attenuated seismic trace to form the internal multiple attenuated seismic image. A system including a seismic source, a plurality of seismic receivers, and a seismic processor for executing the method is disclosed.

A method for seismic geological lineation mapping, wherein a seismic dataset is collected, with information about minor lineations generated by Seismic dataset subtle structural geological features in an underground earth formation. Seismic attribute volumes are identified in the seismic dataset, relating to trace continuity, amplitude, frequency and phase. The attribute volumes may have an insufficient resolution to display the minor lineations. A seismic multivolume lithological lineation map is generated, in which single attribute 92d lineation maps generated for each of the identified seismic attribute volumes are combined to accurately display the minor lineations generated by the subtle geological features.

Noise can be attenuated in marine seismic data from a marine seismic survey. A first near-continuous measurement of a wavefield and a second near-continuous measurement of the wavefield recorded from a marine seismic survey can be equalized, a coherent portion of the equalized second near-continuous measurement can be collapsed, and a noise model can be derived. The noise model can be subtracted from the second near-continuous measurement.