The invention discloses a full-waveform inversion method for VSP seismic data converted waves. Uplink PS converted waves are separated through a global optimization parameter inversion method; transverse wave speed is claculated according to an empirical formula, and is subjected to smoothing processing to obtain an initial transverse wave speed model; an elastic wave equation of longitudianl andtransverse wave separation is solved to obtain a forward propagation longitduinal and transverse wave field and simulated VSP PS wave record of each time step; an accompanying elastic wave equation oflongitudinal and transverse wave separation is solved to obtain back propagation longitduinal and transverse wave field of each time step; a forward propagation longitudinal wave field and a back propagation transverse wave field are adopted to calculate a transverse wave speed gradient; a three-point parabola fitting method is adopted to obtain an iteration step size; a transverse wave speed model is updated through an L-BFGS method; and multi-scale inversion is performed from low frequency to high frequency by applying Wiener filtering. The full-waveform inversion method for VSP seismic data converted waves has the beneficial effect of improving the precision of the full-waveform inversion of the VSP seismic data converted waves and improving an inversion effect of a complex structure through a longitudinal and transverse wave separation strategy.

Full-waveform inversion method for VSP seismic data converted waves

The invention discloses a seismic multi-attribute fusion method based on Shearlet-fastICA. The method is characterized by comprising the following steps: S1, preprocessing seismic attribute, then carrying out shearlet transformation, and determining initial low-frequency subband coefficients and initial high-frequency subband coefficients of different seismic attribute data in a spatial domain; S2, respectively mapping the initial low-frequency subband coefficients and the initial high-frequency subband coefficients from the spatial domain to an ICA domain by using an ICA primary function; S3, carrying out fusion in the ICA domain to determine fused low-frequency subband coefficients and fused high-frequency subband coefficients; and S4, mapping the fused low-frequency subband coefficients and the fused high-frequency subband coefficients back to the spatial domain from the ICA domain and carrying out Shearlet reconstitution to obtain seismic attribute fusion results. According to the seismic multi-attribute fusion method based on Shearlet-fastICA, the mutual redundancy is eliminated by the fused attribute data; the relevant characteristics of the geological mass can be more clearly and obviously described; the powerful technical support is supplied to subsequent reservoir prediction and construction interpretation.

Seismic multi-attribute fusion method based on Shearlet-fastICA

The invention discloses a curvelet domain Radon transform noise suppression method for a loess tableland region. The curvelet domain Radon transform noise suppression method comprises the steps of: performing curvelet forward transform on original seismic data to obtain matrixes of curvelet coefficient domains in different directions and of different scales; performing Radon forward transform on the matrixes one by one so as to transform data of the curvelet coefficient domains into a Radon domain, and conducting threshold filtering on the matrixes one by one, wherein interference waves are manifested by points or energy groups with strong energy in the Radon domain, random noise is manifested by unfocused energy, and effective waves are not focused but are still manifested by focused energy greater than the random noise, and the interference waves can be effectively eliminated through threshold filtering; subjecting the data to Radon inverse transform to be transformed into the curvelet coefficient domains from the Radon domain; and subjecting the data in the curvelet domain to curvelet inverse transform to obtain final data. The curvelet domain Radon transform noise suppression method can suppress the strong-energy coherent noise in the original data effectively, thereby greatly improving a signal-to-noise ratio of the seismic data, and providing effective, much more and high-quality seismic information for the follow-up earthquake interpreter.

Curvelet domain Radon transform noise suppression method for loess tableland region

The invention discloses a denoising method based on well logging-seismic combination. The method is characterized in that relationship is established between synthesis records manufactured by well logging information and seismic information, noise in the seismic information is removed, and the signal to noise ratio of the seismic information is increased. Because the seismic information, especially a high-frequency component, is submerged into the noise and the finding of a noise rule is difficult, the conventional denoising method only utilizes the seismic information per se, so that the removal of the noise is difficult. The denoising method has the advantages that the synthesis records obtained by converting the acoustic wave well logging information are regarded as noise-free expected output, and a seismic record is used as input; when mathematic relationship between the synthesis records and the seismic record is established, an effective signal is enhanced, a noise signal is weakened, and the purposes of denoising and increasing a signal to noise ratio are realized; by combining the synthesis records of the well logging information and the seismic record, the nonregular noise can be removed.

Denoising method based on well logging-seismic combination

The invention discloses a ground penetrating radar data denoising method and aims to utilize shear wave transformation and singular value decomposition to realize noise filtering to enhance effective echo signals. According to the method, firstly, singular value decomposition is utilized to realize separation and filtering of direct waves, secondly, shear wave transformation is utilized to process the ground penetrating radar data to acquire a coefficient matrix of a transformation domain, and singular value decomposition is carried out for the coefficient matrix. If the data contains effective signals, a sparse degree is relatively high, a characteristic matrix after decomposition contains a value having a relatively large integral contribution rate; if the data only has noise, characteristic values of a characteristic value matrix are relatively average, and the characteristic values of the characteristic value matrix after decomposition are relatively uniformly dispersed for the integral contribution rate. According to the method, filtering processing on the data is carried out, shear wave inverse transformation for the data after processing is carried out, and the ground penetrating radar data after denoising is acquired.

Combined shear wave transformation and singular value decomposition ground penetrating radar data denoising method

The invention provides a seismic data combined denoising method based on curvelet transform and singular value decomposition. The combined denoising method based on curvelet transform and singular value decomposition comprises carrying out direction control and noise variance reduction through curvelet transform; partially flattening lineups through improved singular value decomposition, sequentially processing each data point and carrying out effective suppression on the noise of the whole seismic section; and combining the curvelet transform and singular value decomposition through quadtree decomposition. The technique, combined with good denoising effect of singular value decomposition and anisotropy and multi-scale characteristics of curvelet transform, can improve the signal to noise ratio of the seismic data, protect the effective signals while suppressing the random noise, can effectively remove image artifacts, and keep dynamical features of the seismic wave, and is an effective noise suppression technique.

Combined denoising method based on curvelet transform and singular value decomposition

The invention discloses a well-constrained unstable state phase correction method which plays an important role in seismic data waveform uniformity correction, and aims to provide a well-constrained unstable state phase correction method under a local seismic attribute and local plane wave model. The method not only takes the unstable state of a wavelet phase into consideration, but also makes full use of the advantage of high phase correction precision of logging synthetic seismic record. Logging data and the well side seismic record are enveloped to form a model track, the local phase attribute of well side seismic data is estimated by the aid of local similarity criteria, phase information of the well side seismic track is interpolated into a whole seismic section by the aid of local inclination information, so that phase information changing along with time and space is acquired, and the phase of the whole section can be corrected by the aid of the information. Compared with other methods, the method is more reasonable.

Well-constrained unstable state phase correction method

The invention belongs to the field of oil-gas exploration seismic data processing, and relates to a logging information constrained waveform inversion method capable of effectively improving integrated inversion effects and iterative convergence speed of a model. The method includes the steps: performing spatial interpolation on logging data according to an initial speed model and building an accurate prior speed model; synthesizing a seismic record by a staggered-grid finite difference method and calculating a residual wave field; building a logging data constrained regularized inversion equation, resolving a velocity updating quantity, updating a velocity model and calculating gradient directions under the constraint of logging data according to a forward wave propagating field and a reverse wave propagating field acquired by seismic forward simulation; correcting the gradient directions and calculating full waveforms in a time domain by a conjugate gradient method; updating velocity parameters by an iterative formula, judging whether the velocity parameters conform to iterative convergence conditions or not, and outputting results. According to the method, logging data information is added, information of a geological structure is taken into consideration, and the integrated inversion effects and the iterative convergence speed of the model can be improved.

Logging information constrained waveform inversion method

The invention provides a seismic data gap compensation method based on frequency-space domain wave field continuation, which comprises the steps of carrying out three-dimensional Fourier transform on three-dimensional seismic data, and converting seismic data of a (x, y, z) domain into to kx-ky-f domain; carrying out continuation on the wave field of non-deletion trace seismic data according to a wave field continuation relation in a time-space domain by using spatial coherence of seismic signals, acquiring wave field information of a deletion trace, and then carrying out three-dimensional Fourier transform so as to acquire compensation data of the (x, y, z) domain. According to the invention, three-dimensional Fourier transform belongs to orthogonal transform and has good amplitude preservation performance in the kx-ky-f domain and the (x, y, z) domain, so that signals before and after changes are enabled to be consistent in energy. The method provided by the invention carries out deletion seismic data compensation through wave filed continuation, and has specific geophysical significances. Meanwhile, the seismic data gap compensation method adopts fast Fourier transform, and has high computing efficiency.

Seismic data gap compensation method based on frequency-space domain wave field continuation

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Papers

Combined denoising method based on curvelet transform and singular value decomposition

Well-constrained unstable state phase correction method

Logging information constrained waveform inversion method

Seismic data gap compensation method based on frequency-space domain wave field continuation