G01V1/368

3D TAU-P COHERENCY FILTERING
20200371263 · 2020-11-26 ·

Systems and methods of performing a seismic survey are described. The system can receive seismic data in a first domain, and transform the seismic data into a tau-p domain. The system can identify a value on an envelope in the tau-p domain, select several values on the tau-p envelope using a threshold, and then generate a masking function. The system can combine the masking function with the tau-p transformed seismic data, and then perform an inverse tau-p transform on the combined seismic data. The system can adjust amplitudes in the inverse tau-p transformed combined seismic data, and identify one or more coherent events corresponding to subsea lithologic formations or hydrocarbon deposits.

MITIGATION OF DISTRIBUTED ACOUSTIC SENSING GAUGE LENGTH EFFECTS USING INVERSION
20200333487 · 2020-10-22 ·

A method to generate a vertical seismic profile includes acquiring a set of distributed acoustic sensing measurements from a set of overlapping measurement channels on an optical fiber, wherein each of the set of distributed acoustic sensing measurements are measured at a gauge length. The method also includes generating a set of virtual seismic measurements corresponding with subdivisions in the set of overlapping measurement channels based on the set of distributed acoustic sensing measurements and generating the vertical seismic profile based on the set of virtual seismic measurements.

Non-uniform optimal survey design principles

Method for acquiring seismic data is described. The method includes determining a non-uniform optimal sampling design that includes a compressive sensing sampling grid. Placing a plurality of source lines or receiver lines at a non-uniform optimal line interval. Placing a plurality of receivers or nodes at a non-uniform optimal receiver interval. Towing a plurality of streamers attached to a vessel, wherein the plurality of streamers is spaced apart at non-uniform optimal intervals based on the compressive sensing sampling grid. Firing a plurality of shots from one or more seismic sources at non-uniform optimal shot intervals. Acquiring seismic data via the plurality of receivers or nodes.

High resolution seismic data derived from pre-stack inversion and machine learning

A system and method combines model-based inversion and supervised neural networks to develop high resolution rock property volumes from surface seismic data. These volumes have higher frequency and are calibrated to fit well log data. In addition to rock volumes, a Reflection Coefficient (RC) volume is derived from the acoustic impedance volume. The RC volume has much higher frequency, better lateral continuity, and ties to the well logs better than conventional seismic or frequency enhanced data. By interpreting and mapping with this RC volume, a much more accurate depth model can be built, which allows for a horizontal well to be accurately drilled.

Seismic acquisition method and apparatus

The presently disclosed seismic acquisition technique employs a receiver array and a processing methodology that are designed to attenuate the naturally occurring seismic background noise recorded along with the seismic data during the acquisition. The approach leverages the knowledge that naturally occurring seismic background noise moves with a slower phase velocity than the seismic signals used for imaging and inversion and, in some embodiments, may arrive from particular preferred directions. The disclosed technique comprises two steps: 1) determining from the naturally occurring seismic background noise in the preliminary seismic data a range of phase velocities and amplitudes that contain primarily noise and the degree to which that noise needs to be attenuated, and 2) designing an acquisition and processing method to attenuate that noise relative to the desired signal.

NONSTATIONARY MAXIMUM LIKELIHOOD METHOD TO ESTIMATE DISPERSION SPECTRA FOR FULL WAVEFORM SONIC LOGGING
20200292726 · 2020-09-17 · ·

The present disclosure describes methods and systems for estimating dispersion spectra for full waveform sonic (FWS) logging. One computer-implemented method includes receiving FWS data, performing frequency-spatial (FX) transform on the FWS data, using a nonstationary predictive error filtering (PEF) inversion on the transformed FWS data to estimate local matrix L and matrix P, calculating an inverse covariance matrix based on the estimated local matrix L and matrix P, and obtaining a nonstationary maximum likelihood method (MLM) spectra based on the inverse covariance matrix.

Simultaneous wavefield reconstruction and receiver deghosting of seismic streamer data using an L1 inversion

Raw 3D seismic streamer wavefield data is received as a receiver-ghosted shot gather. The received receiver-ghosted shot gather shot gather is processed into a normalized form as normalized data. The normalized data is partitioned into a plurality of user-defined sub-gathers and processed to generate a complete receiver-deghosted shot gather. Output of the complete receiver-deghosted shot gather is initiated.

Pattern-Guided Dip Estimation
20200271826 · 2020-08-27 ·

Innovative aspects of the subject matter described in this specification may be embodied in methods that include obtaining a seismic data image. A first plane-wave destruction filter dip estimation is applied to the seismic data image to generate an initial dip model. A second plane-wave destruction filter dip estimation is applied to the seismic data image using the initial dip model to generate a pattern-guided dip estimation. The pattern-guided dip estimation is stored in a data store.

3D tau-P coherency filtering
10754051 · 2020-08-25 · ·

Systems and methods of performing a seismic survey are described. The system can receive seismic data in a first domain, and transform the seismic data into a tau-p domain. The system can identify a value on an envelope in the tau-p domain, select several values on the tau-p envelope using a threshold, and then generate a masking function. The system can combine the masking function with the tau-p transformed seismic data, and then perform an inverse tau-p transform on the combined seismic data. The system can adjust amplitudes in the inverse tau-p transformed combined seismic data, and identify one or more coherent events corresponding to subsea lithologic formations or hydrocarbon deposits.

SIMULTANEOUS WAVEFIELD RECONSTRUCTION AND RECEIVER DEGHOSTING OF SEISMIC STREAMER DATA USING AN L1 INVERSION
20200257013 · 2020-08-13 · ·

Raw 3D seismic streamer wavefield data is received as a receiver-ghosted shot gather. The received receiver-ghosted shot gather shot gather is processed into a normalized form as normalized data. The normalized data is partitioned into a plurality of user-defined sub-gathers and processed to generate a complete receiver-deghosted shot gather. Output of the complete receiver-deghosted shot gather is initiated.