中国科学技术大学 Jia Xiaofeng--Home-- Congcong Yuan, Xiong Zhang, Xiaofeng Jia and Jie Zhang(*), 2020, Time-lapse velocity imaging via deep learning, Geophysical Journal International, 220(2): 1228-1241.

Congcong Yuan, Xiong Zhang, Xiaofeng Jia and Jie Zhang(*), 2020, Time-lapse velocity imaging via deep learning, Geophysical Journal International, 220(2): 1228-1241.

Release time:2021-07-26

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Abstract:: It is of great significance and a great challenge to quickly and effectively monitor subsurface time-lapse velocities in the earth. Over the past few decades, regularized iterative methods, such as traveltime and waveform inversions, have been presented to monitor velocity changes. Due to high processing cost, these iterative methods have been hardly used in practice to investigate the subsurface velocity changes in real time. In this study, we propose a new timelapse imaging technique that effectively eliminates these limitations and directly produces accurate velocity changes from the time-lapse data. The approach uses a fully convolutional neural network (FCN) to perform the inverse problem. The network architecture consists of a contracting path to quickly extract the features of waveform data and a symmetric expanding path to yield an accurate velocity model.With the known baseline velocity and data, we cast a mapping between time-lapse data and target velocity changes via the proposed FCN algorithm. Along with the observed time-lapse data, this mapping will generate a predictive estimation of the target velocity changes. We demonstrate the efficiency and accuracy of our approach in three 2-D synthetic tests. The proposed technique is able to invert the velocity changes successfully with much higher efficiency than the regular double-difference full waveform inversion.