关键词: 电磁波, 电阻率, 随钻测井仪, 对称补偿, 数值模拟, 机械设计, 有限元方法, 电路设计及应用

Abstract: This paper analyzes the present conditions of electromagnetic propagation resistivity LWD tool both at home and abroad and comes up with the necessity and urgency of research and development of electromagnetic propagation resistivity LWD tool. The general design plan is based on the measurement principle and designing indexes of electromagnetic propagation resistivity LWD tool. The research and design are focused on electromagnetic propagation resistivity method, design of antenna, mechanical structure and electronic circuit. The 3D limited element method is used to bring electromagnetic LWD under numerical simulation study, optimizing the design of tool structure and probing characters. The design is also optimized for drilling collar mechanical layout, antenna structure and threading hole structure while the detailed design of circuit is focused on how to acquire attenuation amplitude of high-frequency weak acceptance signals and phase differential information. The tool is tested on the field after its successful research and development. The results indicate that the tool is good at compatibility and repeatability of logging curves and satisfies the demand for geological pilot and formation interpretation and evaluation.