地-井方位激电观测异常特征研究

A study on anomaly of surface-borehole direction induced polarization survey

为系统了解地-井方位激电异常特征,利用有限单元法对地-井方位激电观测在立方体、板状体等典型地电异常体上的响应进行正演计算,分析了异常体位置、方位距离等变化对观测的影响规律,讨论了地形、钻孔本身对地-井方位观测的影响等.研究结果表明地-井方位观测是探测井旁和井底盲矿体行之有效的方法,利用不同方位上的异常曲线特征,遵循异常场定性分析和"先井口、后其它方位"的分析方法,可大致确定异常体的电性特征和空间展布;地形和钻孔本身对地-井方位观测的影响主要集中在浅部区域.

In order to understand the anomalous characteristics of surface-borehole 5-Direction IP survey systematically, several classical models are designed and calculated using the finite element method to study their corresponding anomalous features, such as abnormal sphere, plate body and so on,which anomalous electric field is measured by the way of surfaee-borehole 5-Direction IP survey. The influences rule of observation which caused by the change of anomalous body position, directions and distance are analyzed, and the influences of terrain and borehole to the surface-borehole 5-Direction IP survey are discussed. Studies show that the surface-borehole 5- Direction IP survey is an effective method in exploring blind ore body near or under the borehole. Using the characteristics of anomalous curve measured at different directions, following the analytical method of abnormal field qualitative analysis and ＇ first the hole, after other positions＇, we can define the electrical characteristics and spatial distribution of anomalous body roughly. Interference of terrain and borehole to the surface-borehole 5-Direction IP survey mainly concentrate in shallow area.