An open-source code of the full waveform inversion method verified by the synthetic GPR data to monitor the CO2 flooding

The full-waveform inversion (FWI) of ground penetrating radar (GPR) data can recover the permittivity and conductivity variations of Debye medium. The numerical tests verify the performance of the FWI method in recovering permittivity and conductivity anomalies and medium boundaries. It further reveals that the process of water and carbon dioxide flooding oil could be successfully monitored with the FWI method by referring to the variations of medium conductivity and permittivity. In terms of the FWI method developed in this study, the forward modelling is run by the auxiliary finite difference method, the model correction in inversions is estimated by minimizing the difference between the energy signals of observed and synthetic data with the L-BFGS method, and the corresponding calculations are running on the GPUs in this study, which are effective in reaching an optimal inversion result and reducing the computational consumptions.