Quantum Annealing And Its Application To Inversion Of Acoustic Impedance

The purpose of seismic inversion is to get the geologic information from seismic wave, which include the subsurface speed structures and the distribution of material properties. They are important for understanding the geologic framework in resource prospecting and exploitation. Because wave impedance is one of the primary stratum parameters, corresponding well to the reservoir, while exactly reflecting the underground lithology, it is an important parameter for forecasting the reservoir location and preservation condition. Hence, seismic inversion usually means the wave impedance inversion. The impedance inversion from seismic data is a typical nonlinear problem.Although geophysicists have researched the technique of wave impedance inversion in various views and did their best to improve it, there were still two key problems in practical application:1. At present, most inversions are iterative method based on the model under the restriction of well logging, and the inversion result depends on closely hypothesis of the initial model and the accuracy of constraint condition. If a reasonable initial model and a mode for interpolating and extrapolating the information of well logging do not exist, it is difficult to obtain a believable inversion result in areas far from well.2. The wave impedance inversion based on seismic data is a typical nonlinear problem, and most of their objective functions are multiple-extremum function which brings a practical difficulty in solving these problems, that is the local convergence of the solution. The conventional inversion algorithms such as Generalized Linear Inversion, Maximum Likelihood Inversion adopt the linearization and quasi-linearization to nonlinear problem, which is inevitably trapped into local optimal solution in the process of inverse optimization and increases the nonunique of inversion results. The nonlinear global search algorithm does not rely on the initial model so much, even on the initial model at all, but their amounts of computation are unacceptable.This paper discusses and analyzes the problem in the wave impedance inversion. In light of some advanced research discovery and comparing with Simulated Annealing (SA), seismic wave...