Coherence Analysis And Time-frequency Analysis Of Seismic Data And With Their Applications In Reservoir Characteristics

Coherence analysis and time-frequency analysis of seismic data are two important methods of seismic interpretation and reservoir characterization. This thesis analyzes and summarizes seismic coherence technique and time-frequency analysis. Next, Rayleigh quotient acceleration algorithm and Wigner-Ville distribution are formulated and applied to C₃ algorithm and seismic time-frequency analysis. Application results on the real data show that these modifications can improve the conventional methods and are effective to use in reservoir characterization.The main contents and achievements of this thesis are as follows:(1)The paper reviews in detail the principle of seismic coherence cube and the coherence algorithms of three generations. A theoretical comparison of the three algorithms is discussed and validates that C₃ algorithm has higher resolution and greater stability.(2)In terms of the characteristic of C₃ algorithm, a new idea that using Rayleigh quotient acceleration algorithm increases its computation rate is presented, and their corresponding algorithms and programs are designed. The results of seismic data processing indicate that this algorithm is effective in reducing iterative times and enhancing computation efficiency.(3)This paper discusses the advantages and disadvantages of Short Time Fourier Transform and Wigner-Ville Distribution, and exploits Smoothed Pseudo Wigner-Ville Distribution to eliminate the interference from the cross-terms.(4)Applying the improved C₃ algorithm of Rayleigh quotient acceleration algorithm and the time-frequency analysis technique based on WVD to the 3D seismic data of a study area, it not only obtains the coherence data cube and the time-frequency spectrum of the study area, but also illustrates that the two approaches are quite effective in reservoir characterization.