Research On The Method Of Wavelet Inversion And Its Application In East Sichuan Area

seismic wavelet extraction is one of the very important part of seismic inversion. Acurate estimation of seismic wavelet Is very important to hige-resolution, hige signal-noise ratio and high fidelity petroleum exploration and production data procession. This paper datailed Introductes the Basic Principle of homomorphic inverse filtering, generalized linear inversion and spreading phase spectrum method, and establed seismic record model based on convolution model, then makes theory and real data proceding research on seismic wavelet extraction throw the above methods. The homomorphic inverse filtering method is based on that the coefficient series is varied and the seismic neighbouing traces is on the whole variant. When selecting time-window on profile,select a stack segment over the high signal-noise ration and resolution, Alignment rather accord, and succession quite well target zone,then make the time-window compel Randomized, it means adding a random number on the every time start point of time-window of the selected same one stack segment, to make evey start point accorded random distribution, so reflection coefficient series on the evey time-window will redistribute accorded it. so it meet that the reflection proficient series is varied and the seismic wavelet keep invariant. The last,overlap the log-spectral of the time-window, to improv the energe of invaried log-spectral of wavelet, but the energe of varied reflection coefficient series was fully reduced, thereby come to the aim of wavelet extraction. To improve the accuration of wavelet extraction, this paper take the method of log-spectral averagement, wavelet pick-up and reform .generalized linear inversion is a technology of picking up seismic wavelet using CDP overlap seismic trace incersion, its most feature is the error can't accumulate according the deepth. The paper test the effect of initial value error to the result inversion: under the premise of keeping the reflection coefficient sign correct, even to the initial model which deviate far from the real model, the method of generalized linear inversion can make it convergent to the real model.spreading phase spectrum method is to compute the wavelet amplitude spectrum and phase spectrum, and then use the wavelet amplitude spectrum and phase spectrum to transform to complex with Euler Formula, get the wavelet series through inverse Fourier Transform . It is statistically extracted from multi-trace raw seismic record without any phase character suppose.This paper research the feasibility and efficiency of the above methods from different apart. The result of treat to fidelity and real data study shows that homomorphic inverse filtering, generalized linear inversion and spreading phase spectrum method have obvious effect in the seismic wavelet records synthesed in different resolution, signal-noise ratio, phase wawelet inversion.Through the application of the above methods, the precision and efficiency of the seismic wavelet extraction gain obvious enhancement. And the same time, the achievements indicate the broad application future of these methods in the field of the seismic sign processing.Besides, based on the owened data about Southeast of the Sichuan, this paper make wavelet extraction test on the seimesic record gathered from physical model and virtually gathered from field. And make horizon calibration, deconvolution, Impedance Inversion and sedimentary facies inversion proceding on the seismic records using the extracted seismic wavelet.the results has demonstrated the corrcetion and the efficiecnt of the wavelet inversion methods introducted in the paper.