Three-component Detection Of Transient Electromagnetic Method Based On Conductivity Depth Imaging

Transient electromagnetic method is an artificial source time-domain electromagnetic exploration method.In recent years,it has been widely used in mineral resources exploration,prospecting of water resources,engineering geological exploration and other fields.It has some advantages such as high work efficiency,large exploration depth and little influence by terrain.The three-component detection of transient electromagnetic method increases the amount of data collected and allows a more intuitive observation of the geological body.In order to make full use of the three-component data,it is necessary to further explore the multi-component response characteristics and establish a transient electromagnetic multi-component interpretation theory,which helps to improve the resolution and accuracy of the detection.Conductivity depth imaging is an approximate inversion method.Based on this,the three-component conductivity depth imaging method is studied,which has guiding significance for actual production work.Based on the theory of time domain electromagnetic method,this paper studies the three-component detection of transient electromagnetic method and the multi-component conductivity depth imaging.The main research contents are as follows:1.Through the forward modeling of the 3D model,the three-component response characteristics of the fixed loop system are analyzed.And research on the detection capability of transient electromagnetic method;2.Establish different fault models and study the exploration capability of transient electromagnetic three-component detection for faults based on multi-component conductivity depth imaging method;3.Verify the validity and correctness of the above method by three-component detection test.Through the above research,the following conclusions were obtained:First,through the conductivity depth imaging,the change trend and the relative resistivity of the subsurface medium can be obtained,thus achieving qualitative analysis of the electrical relationship of the subsurface medium.The vertical component has a high longitudinal resolution;with the horizontal component increases the lateral resolution and reflects the abnormal body boundary.Comprehensive analysis of multi-component conductivity depth imaging results contributes to the identification of subsurface anomalies.Second,the fault can be identified by conductivity depth imaging,and the fault is reflected as a low-resistance anomaly in the apparent resistivity pseudo-section.Combined with the results of multi-component imaging,a comprehensive analysis helps identify fault structures.Third,through the transient electromagnetic three-component detection experiment verification,the fault anomaly can be identified according to the imaging results.Multi-component conductivity depth imaging provides fast imaging results and qualitative interpretation for actual work.The effectiveness of the three-component detection and conductivity depth imaging methods was further verified.