The Methodological Research Of Wave Impedance Inversion Based On Genetic Algorithms

The genetic algorithm is a kind of searching method, which simulates the natural evolution. Because the genetic algorithm is not restricted by the restriction hypothesis of search space and does not require the searching space to be continuous and derivative, thus it is applied to various domains widely. This paper introduced wave impedances and genetic algorithms' research actuality, genetic algorithms' theory elements, and brought forward seismic wave impedances that had been introduced from the genetic algorithms based on discussed algorithm's convergence, expounded wave impedances inversion elements based on genetic algorithms. It researched emphasizely genetic algorithms with binary character string coding, real coding,and cluster migration for real coding,genetic operation is the best optional optimization preserving strategy operation, stochastic uniform selection,gaussian mutation and several cluster migration based on researching widely the genetic algorithms' characteristics of varied coding modes, selection modes, crossover modes and mutation modes. This genetic algorithm approved efficiency and convergence passing through De Jong and Ackley experiment function.Using genetic algorithms inverse theoretical model with the different vavelet, different noise, and different initial wave impedances, as well as analysis for the result and character, also inverse simulate practical datum with part of the CMP stack gather of Marmousi model and the actual data inversion is a good result comparatively. As a whole, the result of wave impedances inversion based on genetic algorithms is more satisfactory.