2 results about "Bregman iteration" patented technology

The application discloses a kind of sparse generalized W transform gas reservoir characterization time-frequency analysis method, for the first time L1 norm is introduced to the mathematical relationship between generalized W transform and seismic signal for sparse constraint, and is solved using Bregman iteration algorithm, to obtain a kind of analysis result with higher time-frequency resolution.The method absorbs the advantage that generalized W transform highlights low-frequency information of seismic signal, avoids the problem of main frequency splitting, and provides a more sparse time-frequency representation for non-stationary seismic signals. When applied to the time-frequency analysis of actual seismic data, it can provide a high-precision seismic spectral decomposition result for gas reservoirs, thereby more accurately delineating the low-frequency abnormal area of gas reservoir.

The application discloses a normalized W transform method based on local frequency constraint and used for gas reservoir identification. The method firstly inputs a seismic signal, adopts total variation regularization combined with Bregman iteration to solve local frequency, and improves stability and noise resistance of frequency estimation; on the basis, a standard deviation function fusing local frequency constraint, frequency deviation suppression and amplitude adaptive adjustment is constructed, adaptive regulation and control of a W transform analysis window are realized, a time-varying main frequency normalization mechanism is introduced, and a high-resolution time-frequency spectrum is obtained; finally, at least two characteristic frequency points are selected based on energy accumulation distribution of the time-frequency spectrum, linear fitting is performed on the characteristic frequency points, a frequency attenuation gradient attribute is calculated, and the frequency attenuation gradient attribute is used for representing distribution characteristics of the gas reservoir.