基于ANSYS的套管对EM-MWD信号传输的影响分析

Analysis on the Influence Rule of Casing on EM-MWD Signal Transmission Based on ANSYS

摘要:

评价电磁波随钻测量（EM-MWD）信号传输效果，不可忽视套管对信号传输的影响，而套管对信号传输影响极为复杂，很难用数学模型进行全面分析。基于此，采用ANSYS有限元软件，对EM-MWD在套管中信号传输进行建模仿真，从地面电流密度及接收信号压差方面，分析套管对EM-MWD信号传输影响规律。仿真结果表明：绝缘短节出套管，套管对信号起引导作用，反之，套管对信号起屏蔽作用；低电阻率钻井液对EM-MWD在套管中的信号传输影响大。

Abstract:

The influence of casing can not be ignored for evaluating the transmission effect of EM-MWD signal, and it is difficult to analyze this effect with mathematical models because of the casing's extremely complicated effects. Therefore, modeling and stimulation of EM- MWD signal transmission in the casing were made by ANSYS finite element software to analyze the influence rule of casing on EM-MWD signal transmission in the aspects of ground current density and ground receiver voltage. The stimulation results show that the casing plays a guiding role to the signal when insulation nipple is out of the casing, and conversely, the casing has a shielding effect on the signal; low resistivity drilling fluid has a great influence on EM-MWD signal transmission in the casing.