Patent classifications
G01V1/368
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.
Methods for simultaneous source separation
A multi-stage inversion method for deblending seismic data includes: a) acquiring blended seismic data from a plurality of seismic sources; b) constructing an optimization model that includes the acquired blended seismic data and unblended seismic data; c) performing sparse inversion, via a computer processor, on the optimization model; d) estimating high-amplitude coherent energy from result of the performing sparse inversion in c); e) re-blending the estimated high-amplitude coherent energy; and f) computing blended data with an attenuated direct arrival energy.
Directional Q compensation with sparsity constraints and preconditioning
A method for directional Q compensation of seismic data may comprise calculating angle-dependent subsurface travel times; applying directional Q compensation to the prestack seismic data to obtain Q-compensated data in time-space domain, wherein the directional Q compensation is based on the angle-dependent subsurface travel times; and using the Q-compensated data to generate an image of the subsurface. Directional Q compensation may comprise determining an angle-dependent forward E operator and an angle-dependent adjoint E* operator using the angle-dependent subsurface travel times; and applying a sparse inversion algorithm using the angle-dependent operators to obtain a model of Q-compensated data. The angle-dependent operators may be preconditioned by introducing ghost and source effects in a wavelet matrix and a transpose of the wavelet matrix, respectively, such that applying a sparse inversion algorithm using the preconditioned angle-dependent operators is used to obtain a model of Q-compensated, deghosted data without source effects.
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.
System and method for seismic sensor response correction
A method for processing seismic data includes receiving, by a seismic data processing system, signals representing seismic data recorded at a remote location. In addition, the method includes receiving, by the seismic data processing system, identification of a sensor via which the signals were acquired. Further, the method includes retrieving, by the seismic data processing system, a sensor transfer function that corresponds to the sensor and relates the motion of the sensor to the signals. The method also includes generating, by the seismic data processing system, based on the sensor transfer function and a reference transfer function, an inverse filter that when applied to the signals changes parameters of the signals to correspond to the reference transfer function. Moreover, the method includes applying, by the seismic data processing system, the inverse filter to the signals to conform the parameters of the signals to the reference transfer function.
Mitigation of distributed acoustic sensing gauge length effects using inversion
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.
Method and apparatus for deblending seismic data using a non-blended dataset
A non-blended dataset related to a same surveyed area as a blended dataset is used to deblend the blended dataset. The non-blended dataset may be used to calculate a model dataset emulating the blended dataset, or may be transformed in a model domain and used to derive sparseness weights, model domain masking, scaling or shaping functions used to deblend the blended dataset.
Estimating an earth response
Estimating an earth response can include deconvolving a multi-dimensional source wavefield from near-continuously recorded seismic data recorded at a receiver position. The deconvolving can include spreading the near-continuously recorded seismic data across a plurality of possible source emission angles. The result of the deconvolution can be the earth response estimate.
WAVE-FIELD SIMULATION METHOD FOR EXTENDING FINITE-DIFFERENCE STABILITY CONDITIONS, AND APPARATUS AND MEDIUM FOR IMPLEMENTING SAME
A wavefield simulation method for extending the explicit finite-difference stability condition comprises: performing a time-step iteration on the basis of a wave-field numerical simulation model and adopting the spatial filtering method to filter out wave-field components appearing in the high wave number region (S1); when all time-step iterations end, saving wave-field data that obtained from the time iterations (S2); performing the inverse time-dispersion transform on the target wave-field data required to be output from the wave-field data, so as to obtain the wave-field data with time-dispersion removed (S3); and saving the wave-field data after the inverse time-dispersion transform processing (S4). Further provided are an electronic apparatus and a computer-readable storage medium used to implement the wave-field simulation method for extending the explicit finite-difference stability conditions.
Velocity Tomography Using Time Lags of Wave Equation Migration
Velocity tomography using time lags of wave equation migration is disclosed. Seismic tomography is a technique for imaging the subsurface of the Earth with seismic waves by generated a migration velocity model from a multitude of observations using combinations of source and receiver locations. The migration velocity model may be updated in order to reduce depth differences of reflection events (also called residual depth errors (RDE)). Direct measurement of RDE may be difficult in certain complex subsurface areas. In such areas, the RDE may be reconstructed based on time lags of wave equation migration and then used to update the migration velocity model. In particular, the RDE may be directly reconstructed from the time lags of wave equation migration, such as based on a direct relation between RDE and the time lags.