Inversion Velocity Analysis by One-Way Wave Equation
Z. Yu and Y. Liu
Event name: 81st EAGE Conference and Exhibition 2019
Session: Poster: Velocity Model Estimation A
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 677.46Kb )
Price: € 20
Migration velocity analysis (MVA) is an image domain technique to determine large-scale structure of the subsurface velocity model. However, due to limited surface acquisition geometry and uneven illumination, migration smiles and spurious oscillations around the reflector positions may lead to local minimal in the inversion process. For more stable results, in this paper, we have developed new expressions based on true-amplitude, one-way wave-equation operators and used those expressions to direct velocity analysis which is called inversion velocity analysis (IVA). The differential semblance optimization (DSO) objective function is adopted to evaluate the inverted images quality. Compared to traditional MVA method, the modified inversion method attenuates migration smiles by compensating for geometric spreading and uneven illuminations. Also, the direct inversion has influence on the gradient, with slightly modified objective function, the spurious oscillations around reflectors in the gradient can be attenuated. Numerical examples illustrate the effectiveness of the IVA which offers new perspective to large-scale model construction.