Institution:土建与水利学院
Journal:Geophys. J. Int
Key Words:Electrical resistivity tomography (ERT); Downhole methods; Inverse theory; Numerical modelling; Time-series 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 via4-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.
First Author:Bin Liu
Correspondence Author:Zhengyu Liu
All the Authors:Xinxin Zhang,Shenhua Liu,NingWang,JingWang,Deqiang Mao,Yonghao Pang
Document Code:69CCB9166F9B4FD39916469A16F7E7C8
Discipline:Engineering
First-Level Discipline:Civil Engineering
Document Type:J
Volume:221
Page Number:586-602
Impact Factor:2.574
Translation or Not:No
Date of Publication:2020-04
Included Journals:SCI