2D acoustic FWI using the multicomponent marine data: Application to North Sea OBC data

Ocean bottom measurement allows us to enhance the performance of acoustic full waveform inversion (FWI) for marine data by utilizing both the scalar and vector components of wavefields. In this study, we propose a strategy of FWI using both pressure and vertical particle acceleration data. To do so, we first analyze the sensitivity kernels and gradient directions of pressure and horizontal and vertical particle acceleration components for a synthetic model generated after the real North Sea reservoir. Because particle accelerations have amplitude variations along the direction of wave propagation, we observe that FWI coverages of the gradient directions for each acceleration component are different. Based on the observations from the sensitivity kernels and gradient directions, we design a sequential inversion strategy that utilizes pressure data first and then vertical acceleration data. We compare the performance of the proposed sequential FWI strategy to the conventional single-component FWI strategies for the North Sea multicomponent OBC (ocean bottom cable) data. Real data examples show that the proposed sequential FWI strategy provides better inversion results than the conventional strategies. In other words, the proposed strategy describes detailed structures and enhances continuity of reflectors in reverse time migration (RTM) image.