Multiscale phase inversion for 3D ocean‐bottom cable data

Abstract

We invert three‐dimensional seismic data by a multiscale phase inversion scheme, a modified version of full waveform inversion, which applies higher order integrations to the input signal to produce low‐boost signals. These low‐boost signals are used as the input data for the early iterations, and lower order integrations are computed at the later iterations. The advantages of multiscale phase inversion are that it (1) is less dependent on the initial model compared to full waveform inversion, (2) is less sensitive to incorrectly modelled magnitudes and (3) employs a simple and natural frequency shaping filtering. For a layered model with a three‐dimensional velocity anomaly, results with synthetic data show that multiscale phase inversion can sometimes provide a noticeably more accurate velocity profile than full waveform inversion. Results with the Society of Exploration Geophysicists/European Association of Geoscientists and Engineers overthrust model shows that multiscale phase inversion more clearly resolves meandering channels in the depth slices. However, the data and model misfit functions achieve about the same values after 50 iterations. The results with three‐dimensional ocean‐bottom cable data show that, compared to the full waveform inversion tomogram, the three‐dimensional multiscale phase inversion tomogram provides a better match to the well log, and better flattens angle‐domain common image gathers. The problem is that the tomograms at the well log provide an incomplete low‐wavenumber estimate of the log's velocity profile. Therefore, a good low‐wavenumber estimate of the velocity model is still needed for an accurate multiscale phase inversion tomogram.

InversionNet3D: Efficient and Scalable Learning for 3D Full Waveform Inversion

“…We found that it is not necessary to include all 25 channels in the input due to the redundancy among seismic data records, so our input only contains 8 channels (6,7,8,11,13,16,17,18). See Figure 11 for an explanation of these serial numbers.…”

“…Key ingredients of FWI are an efficient forward-modeling engine and a local differential approach to calculate the gradient and the Hessian operators [3]. As 3D surveys become widely implemented, 3D FWI are required to solve complex geological cases [4], [5], [6]. However, both the computational cost of forward-modeling and the gradient calculation are much higher in the 3D cases than the 2D cases [7], [8].…”

Source-Independent Waveform Inversion Method for Ground Penetrating Radar Based on Envelope Objective Function

“…Moreover, the multi-scale inversion strategy is also applicable to the GPR domain [24]. To solve the problems existing in the traditional FWI inversion process, a series of waveform inversion methods based on special objective functions are proposed [25][26][27][28][29][30][31]. Subsequently, the partial information waveform inversion method based on special objective function was successfully developed in the field of GPR [32][33][34].…”

Multiscale phase inversion for vertical transverse isotropic media

“…In addition, they replaced the magnitudes of the predicted spectra with those of the recorded spectra. This method has been successfully applied to crosswell data (Sun and Schuster, 1993) and surface reflection seismic data (Fu et al, 2017(Fu et al, , 2020Feng et al, 2019a). In this paper, we extend the multiscale phase inversion methodology to data recorded over an anisotropic medium.…”