基于传输线分析的电遥测钻柱信道特性优化  

Optimization of Channel Characteristics of Electric Telemetry Drill String Based on Transmission Line Analysis

作　　者：贾甲[1] 苏义脑 沈跃 王龙 张令坦 盛利民 Jia Jia;Su Yinao;Shen Yue;Wang Long;Zhang Lingtan;Sheng Limin(School of Petroleum Engineering,China University of Petroleum(East China);CNPC Engineering Technology R&D Company Limited;College of Science,China University of Petroleum(East China))

机构地区：[1]中国石油大学(华东)石油工程学院 [2]中国石油集团工程技术研究院有限公司 [3]中国石油大学(华东)理学院

出　　处：《石油机械》2022年第5期24-31,共8页China Petroleum Machinery

基　　金：中央高校基本科研业务费专项“电遥测钻柱的高频信号传输特性研究”(27R1710013A)。

摘　　要：电遥测钻柱是一种具有高数据速率的井下信息传输系统,采用布有导线的钻杆级联成钻柱信道来传输高频信号,由于信号通过钻柱信道时会产生严重衰减,每隔约300 m需加中继器,而过多的中继器会造成系统制造成本的提高及信号传输可靠性的降低。为减少中继器的数量,可通过优化信道的传输特性有效延长中继距离。基于传输线理论和高频变压器原理构建信道的电路模型,通过在钻杆传输线的终端连接一个阻抗补偿网络并改变其电阻值使传输线处于适当的阻抗失配,在传输线终端获得较高的电压增益,达到优化钻柱信道电压传输特性的目的。电路仿真和试验结果表明,基于传输线理论及电路分析所建立的信道电压传输函数数学模型可以反映钻柱信道的信号传输规律。数值计算结果表明,在与Grant Prideco公司的Intelliserv network system系统数据传输速率相当的情况下,中继距离可扩展至2.47倍。研究结果可以为电遥测钻柱信息传输系统的性能优化提供有益的启示及借鉴。Electric telemetry drill string is a kind of downhole information transmission system with high rate of data.Drill pipes with wires are cascaded into drill string channels to transmit high-frequency signals.The signals will be attenuated greatly when passing through the drill string channels,so it is required to add repeaters every 300 m.However,too many repeaters will increase the manufacturing cost of the system and reduce the reliability of signal transmission.In order to reduce the number of repeaters,the relay distance can be extended effectively by optimizing the transmission characteristics of channels.Based on the transmission line theory and the principle of high-frequency transformer,the circuit model of the channel was built.Higher voltage gain was obtained at the terminal of the transmission line by connecting an impedance compensation network at the terminal of the drill pipe transmission line and changing its resistance.As a result,the voltage transmission characteristics of the drill pipe channels were optimized.Circuit simulation and experimental study show that the mathematical model of channel voltage transmission function based on transmission line theory and circuit analysis enables to reflect the signal transmission law of drill string channels.Numerical calculations show that the relay distance can be extended to 2.47 times when the data transmission rate is equal to that of Intelliserv network system of Grant Prideco.The study can provide inspiration and reference for the performance optimization of electric telemetry drill string information transmission system.

关 键 词：随钻测量 电遥测钻柱 中继距离 传输线分析 信道传输特性 阻抗补偿网络 

分 类 号：TE927[石油与天然气工程—石油机械设备]