Modeling High-Frequency Magnetic Coupling Wired Drill Pipe Channel Based on Linear Simulation

In order to extend the repeater-free transmission distance of the high-frequency magnetic coupling wired drill pipe system, it is necessary to select the frequency point of carrier signal and match the impedance between wired drill pipes with different lengths. To this end, a simulation was performed by establishing a channel model to match the impedance of wired drill pipes with different lengths. When the channel model was established, the transmission channel could be divided into a minimum repeating unit called the standard circuit component, which consisted of a coaxial cable and a magnetic coupling coil pair. The coaxial cable transmission line was used to simulate the coaxial cable, while the physical transformer component was used to simulate the magnetic coupling coil pair, and an easy-to-measure hybrid model consisting of distributed parameter components and lumped parameter components was established. First, the parameters of each component were determined according to the material size, physical parameters and instrument measurement results, the standard circuit component model was created by ADS software, and then the circuit simulation was performed by linear simulation of scattering parameters. The simulation results were consistent with the measured results of actual sample, which indicated that the model-based simulation could be used to provide a basis for the optimal design of high frequency magnetic coupling wired drill pipe. The high-frequency magnetic coupling wired drill pipe was optimized by channel modeling, and the repeater-free transmission distance was increased to more than 300 m.