High-accuracy wave-field extrapolation operator based on rational approximation
Bai Min1,2, Chen Xiaohong1,2, Xiong Xiaojun3, Wu Juan1,2
1. State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;
2. CNPC Key Laboratory of Geophysics,China University of Petroleum(Beijing),Beijing 102249,China;
3. College of Geophysics,Chengdu University of Technology,Chengdu,Sichuan 610059,China
Abstract：Based on one-way wave equation,we propose a new wave-field extrapolation operator of high-accuracy using rational expansion method.This operator uses split-step framework and Fast Fourier Transforms(FFT) in wave-field continuation.Analysis results of dispersion curves and numerical experiments show that the imaging capability of this operator is significantly better than split-step Fourier method(SSF).Its imaging capability is nearly as good as Fourier Finite Difference method(FFD).In the aspect of computing efficiency,the operator only needs 3 FFTs and one interpolation,which is one more FFT and interpolation than conventional SSF(needs 2 FFTs) in computation,but two FFTs less than FFD(equivalent to 5 FFTs).It is not only highly accurate,unconditionally stable,but also highly efficient in migration imaging.This method is of important theoretical and practical significance.
