基于倾斜线圈电流源的边界探测机理

Research on Mechanism of Boundary Detection Based on Current Source of Inclined Coil

对于层状地层,地层中的涡流将以不同角度穿过地层界面。轴向发射线圈源与倾斜发射线圈源在地层界面处产生的涡流流动现象是不同的,这也是基于倾斜线圈系的电磁波测量仪器能够识别地层界面的原因。从电磁波传播理论出发,数值模拟研究并可视化分析仪器与地层界面距离不同时地层中的涡流流动特性,从机理上研究具有倾斜线圈系的随钻测井仪器是如何探测地层界面的。

For multi-layer strata,the eddy current in the stratum will pass through the stratum interface at different angles.The vortex flow phenomena at the interface between the axial and inclined emission coil sources are different.This is also the reason that the electromagnetic wave measuring instrument based on the inclined coil system can identify the stratum interface.Based on the theory of electromagnetic wave propagation,the characteristics of eddy current flow in the formation with different distance between instrument and formation interface are studied and visualized by numerical simulation,this paper studies how the logging-while-drilling tool with an inclined coil system detects the formation interface in mechanism.