A rapid four-dimensional resistivity data inversion method using temporal segmentation

作者：Bin Liu, Yonghao Pang, Deqiang Mao, Jing Wang, Zhengyu Liu, Ning Wang, Shenhua Liu, Xinxin Zhang · 发表于：Geophysical Journal International · 年份：2020 · DOI：10.1093/gji/ggaa019 · 被引用次数：39 · 研究领域：Geophysical and Geoelectrical Methods、Geophysical Methods and Applications、Seismic Waves and Analysis

SUMMARY 4-D electrical resistivity tomography (ERT), an important geophysical method, is widely used to observe dynamic processes within static subsurface structures. However, because data acquisition and inversion consume large amounts of time, rapid changes that occur in the medium during a single acquisition cycle are difficult to detect in a timely manner via 4-D inversion. To address this issue, a scheme is proposed in this paper for restructuring continuously measured data sets and performing GPU-parallelized inversion. In this scheme, multiple reference time points are selected in an acquisition cycle, which allows all of the acquired data to be sequentially utilized in a 4-D inversion. In addition, the response of the 4-D inversion to changes in the medium has been enhanced by increasing the weight of new data being added dynamically to the inversion process. To improve the reliability of the inversion, our scheme uses actively varied time-regularization coefficients, which are adjusted according to the range of the changes in model resistivity; this range is predicted by taking the ratio between the independent inversion of the current data set and historical 4-D inversion model. Numerical simulations and experiments show that this new 4-D inversion method is able to locate and depict rapid changes in medium resistivity with a high level of accuracy.