Abstract:During tomography inversion process,especially during ray tomography inversion process,many factors could affect inversion results,the initial model is just one of the important influence factors.By mainly referring the Jannane's study methods for the performance analysis of waveform inversion object function and through a series of theoretical model experiments,the dependence of first arrival travel time tomography on initial model was analyzed,then simply and effectively selecting tomography initial model was discussed and the further selection strategy of the tomography initial model was presented in this paper,the whole process can be summarized as below:①At first to smooth the existing geological model and obtain background field information of the medium (The background field information can also be obtained by integrating the prior information with other mode,such as gradient model);②To subtract background field information and obtain disturbed field;③To conduct low-pass filtering for disturbed field and obtain long wavelength component of the disturbed field;④By adding the long wavelength component of the disturbed field and background field information to obtain tomography initial model.The theoretical model data simulation and field data processing proved rationality and advantages of the selected strategy.
刘玉柱, 丁孔芸, 董良国. 初至波走时层析成像对初始模型的依赖性[J]. 石油地球物理勘探, 2010, 45(4): 502-511.
Liu Yu-zhu, Ding Kong-yun, Dong Liang-guo. The Dependence of first arrival travel time tomography on initial model. OGP, 2010, 45(4): 502-511.