Abstract：A method estimating wave impedance of stratum only based on seismic data and without well data or unreliable well data is presented in the paper,that is poststack seismic blind inversion. First,application of genetic algorithm to directly pick up seismic wavelet from seismic records based on high-order statistics theory;then,creating object function based on Bayesian parameters estimation theory and hypothesizing that the likelihood function is subject to Gauss distribution and parameters of inversion is subject to Cauchy distribution; using wave impedance at known points to carry out constraint to inversed results,which made the results more accurate and reliable.The model tests and practical seismic data processing showed that the method presented in the paper has good application effects and can obtain the parameter of stratum impedance without well data.
