Seismic Impedance Inversion In Thin Reservoirs With High Resolution

Seismic impedance inversion plays an important role in seismic prediction of reservoir.Compressed sensing has increasingly become a hot research direction in the field of seismic signal processing.On account of that it has high resolution and less dependence on the model.In seismic wave impedance inversion field,compressed sensing mainly includes basis pursuit seismic impedance inversion and matching pursuit seismic impedance inversion.Basis pursuit refactorts stratum reflection coefficient by minimize the first norm.Matching pursuit uses the greedy algorithm to match the local signal with the best dictionary elements excellently.This studies basis pursuit and matching pursuit methodology firstly.Analyzing compressed sensing's advantage compared with the traditional method of digital signal processing such as fourier transform and wavelet transform.Unlike traditional digital signal processing technology,Compressed sensing uses a small amount of observations to sparse signal representation by building a dictionary library accordingly.Studing basic pursuit and matching pursuit method about how to apply in the seismic impedance inversion.Analyzing basis pursuit and matching pursuit methods' key factors in the seismic wave impedance inversion.Secondly,researching matching pursuit about the realization of the seismic wave impedance inversion.This chapter mainly completing matching pursuit impedance inversion based on monolayer and multilayer tuning attunement.Matching pursuit applied to the practical seismic records exists unstable decomposition result.This paper proposing,determining the frequency and phase value range of wavelet firstly.The error between original seismic signals and reconstructing seismic signals as well as match the projection values act as conditions of matching judgment.Then,achieving seismic impedance inversion based on basis pursuit,including seismic impedance inversion on the conditions of monolayer and multilayer tuning attunement.This chapter proposes,seismic impedance inversion based on basis pursuit thinking four levels of tuning to improve the inversion of the decomposition rate under the condition of multilayer tuning.In the end,setting up models to analyze basis pursuit's decomposition of the overall consistency advantage and matching pursuit's suboptimization advantage.And analysising their own existing problems under given conditions.Combining with their own advantages can improve the resolution of inversion and accuracy.Concreting implementation method mainly involves the following aspects.Firstly,using matching pursuit to pick up reflectors' optimized seismic wavelets.Secondly,basis pursuit use optimized seismic wavelets to build dictionary library.Finally,using basis pursuit thinking four levels of tuning to decomposite seismic signal by builded dictionary library.Using this method can acquire stratums' wave impedance more accurately.