Suitable Device Parameters for BSCSEM Method

Summary Borehole To Surface Controlled Source Electromagnetic (BSCSEM) Method is an important geophysical electromagnetic exploration technology that has developed rapidly in recent years and has been applied to metal mineral and engineering geophysical exploration. However, there is ongoing debate regarding the effective selection of device parameters for borehole detection. Through three-dimensional numerical simulations, we explored the current propagation characteristics in the BSCSEM method and the impact of device parameters on exploration results. Taking a plate-like anomaly as an example, we analyzed the effects of offset distance, transmitter position, and length on commonly used observation components. The results show that: 1) For a depth of 500m, the offset distance should be controlled within 2km to ensure signal strength and resolution. 2) Accumulated charge is mainly concentrated on the upper and lower surfaces of the anomaly; the closer the source position is to the anomaly at small offset distances, the stronger the response. 3) When the source length is relatively long compared to the thickness of the anomaly, the abnormal signal rapidly attenuates; thus, it is recommended that the source length not be too large to avoid excessive energy dispersion. The conclusions of this study provide guidance for practical exploration.