井下无线射频识别系统作业环境影响因素分析

Analysis on Working Environment Influencing Factors of Downhole RFID System

以无线射频识别(RFID)技术为控制手段与井下工具进行结合,能够很好地突破现有技术瓶颈,解决压裂级数受限等诸多问题。但在实际情况下,井下环境复杂多变,多种因素都会对射频系统的稳定性造成干扰。为解决这一问题,在完成井下RFID通信系统设计的基础上,根据井下RFID系统的结构特点和工作环境,使用Ansoft Maxwell软件建立井下电磁环境有限元仿真模型,探究了各因素对RFID系统的影响程度以及变化规律。分析结果表明,井下工具金属外壳尺寸和压裂液电导率为主要影响因素。对RFID系统进行的信号接收性能试验也验证了系统能够达到所需性能指标。研究结果对于RFID系统的现场应用具有一定的指导作用。

Combination of radio frequency identification ( RFID) technology as a control method with downhole tools can break through the botdeneck of current fracturing technologies and address problems like limited fracturing stages.However, under complex and variable downhole environment, many factors may interfere the stability of the RFID system.To address the problem, based on the designed downhole RFID communication system, according to the structural characteristics and working environment of the downhole RFID system, Ansoft Maxwell software was used to establish the finite element simulation model of the downhole electromagnetic environment to study the influence of various factors on the RFID system.The analyses results show that the metal shell size of the downhole tool and the conductivity of the fracturing fluid are the main influencing factors.The signal receiving performance test of the RFID system is carried out through laboratory tests.The system is proved to achieve the required performance indicators.Engineering suggestions based on the actual situation are proposed.