A computer-implemented method of enhancing a computer to estimate an uncertainty of an onset of a signal of interest in time-series noisy data. A first mathematical model of first time series data that contains only noise is calculated. A second mathematical model of second time series data that contains the noise and an onset of a signal of interest in the second time series data is calculated. A difference is evaluated between a first combination, being the first mathematical model and the second mathematical model, and a second combination, being the first time series data and the second time series data, wherein evaluating is performed using a generalized entropy metric. A specific time when an onset of the signal of interest occurs is estimated from the difference. An a posteriori distribution is derived for an uncertainty of the specific time at which the onset occurs.

Received shot gathers are sorted to a common receiver gather. A target three-dimensional (3D) amplitude spectrum of seismic wavefield direct arrivals is computed from synthetic data. A 3D amplitude spectrum of seismic wavefield direct arrivals in field data is computed for each receiver. A matched filter is calculated from the 3D amplitude spectrum of field data to target response and applied to downgoing seismic wavefields separated from the common receiver gather to generate filtered downgoing seismic wavefields. Time-dependent smoothing of the filtered downgoing seismic wavefields is performed to generate smoothed downgoing seismic wavefields. A cross-correlation is calculated between upgoing seismic wavefields separated from the common receiver gather and the smoothed downgoing seismic wavefields.

A device may include a processor that may recover the signals misallocated in the deblending process of seismic data acquired with simultaneous sources. The processor may update the primary signal estimate based at least in part on a separation operation that separates coherence signals from noise signals in an output associated with the residual determined to be remaining energy for separation. The processor may be incorporated into the iterative primary signal estimate of the deblending process or be applied towards preexisting deblending output. In response to satisfying an end condition, the processor may transmit a deblended output that includes the weak coherence signals recovered from the misallocation or error in the primary signal estimate. The processor may also transmit the deblended output for use in generating a seismic image. The seismic image may represent hydrocarbons in a subsurface region of Earth or subsurface drilling hazards.

A method includes receiving imagery data; fitting a multidimensional polynomial function to at least a portion of the imagery data to generate one or more values for one or more corresponding parameters of the function; and generating curvature attribute data based at least in part on the fitting.

A method for wavefield separation of sonic data is provided. The method comprises estimating direct phases of waveforms of sonic data observed with two or more sensors by using cross-correlation of waveform traces at adjacent sensor locations, removing the direct phases from the observed waveforms, and extracting event signals from the waveforms after removing the direct phases.

The invention notably relates to a computer-implemented method for processing a 4D seismic signal relative to a subsoil, the subsoil including a zone subject to extraction and/or injection, the method comprising: providing the 4D seismic signal; identifying a part of the 4D seismic signal corresponding to a zone of the subsoil distinct from the zone subject to extraction and/or injection; determining a noise model of the 4D seismic signal based on the identified part of the 4D seismic signal; and processing the 4D seismic signal based on the noise model. This improves the field of 4D seismic data processing.

A system and method and non-transitory computer readable medium method for filtering signals representative of microseismic events with an infinite impulse response (IIR) Wiener filter which precludes the need for statistics or prior knowledge of the signal of interest. The second-order statistics of the noise and the noisy data are extracted from the recorded data only. The criteria used to optimize the filter impulse response is the minimization of the mean square error. The IIR Wiener filter was tested on synthetic and field data sets and found to be effective in denoising microseismic data with low SNR (2 dB).

The present disclosure discloses a method and an apparatus for processing seismic data, and belongs to the field of geological surveys. The method comprises: stacking seismic trace gathers in a predetermined range among S seismic trace gathers after a Normal Move Out (NMO) correction processing to obtain a model trace, S being an integer; calculating a correlation coefficient of each seismic trace gather with the model trace, and selecting a K-th seismic trace gather with a maximum correlation coefficient; calculating an optimum point of each seismic trace gather from the K-th seismic trace gather to two sides orderly; and performing a residual NMO correction of the seismic trace gathers according to the optimum points.

Systems and methods for performing focused blind deconvolution of signals received by a plurality of sensors are disclosed. In some embodiments, this may include determining a cross-correlation of first and second signals, obtaining a cross-correlation of a first response function and a second response function based on the cross-correlation of the first and second signals and subject to a first constraint that the first and second response functions are maximally white, and obtaining the first and second response functions based on the cross-correlation of the first and second response functions and subject to a second constraint that the first and second response functions are maximally front-loaded.

Seismic data processing using one or more non-linear stacking enabling detection of weak signals relative to noise levels. The non-linear stacking includes a double phase, a double phase-weighted, a real phasor, a squared real phasor, a phase and an N-th root stack. Microseismic signals as recorded by one or more seismic detectors and transformed by transforming the signal to enhance detection of arrivals. The transforms enable the generation of an image, or map, representative of the likelihood that there was a source of seismic energy occurring at a given point in time at a particular point in space, which may be used, for example, in monitoring operations such as hydraulic fracturing, fluid production, water flooding, steam flooding, gas flooding, and formation compaction.