Developing Through Metal Wireless Sensors in Extreme Conditions for Petroleum Industrial Applications

Metal has been widely used to build containers in the petroleum industry for various applications, such as chemical reaction containers, hazardous materials storage, oil/gas transportation pipelines, and casings for oil wells. The conditions inside the metal containers are often at high temperature and pressure, and it is extremely important to monitor and sense the internal condition in real-time. The metal containers provide an excellent environmental isolation barrier, though it also blocks a sensing signal from transmitting through the metal. In this paper, we have proposed and established a through-metal sensing system that can measure the physical conditions inside the metal container in extreme conditions. The system includes two components: signal transmission and physical sensing. In order to transmit the signal through the thick metal layer, magnetic induction has been employed with ultralow frequency (<; 1 kHz). Our design goal for the physical sensing system is to have the ability to operate under extreme conditions. Therefore, we choose a simple RLC resonator circuit, which only uses simple and robust components: inductor, capacitor, and resistor. The signal transmission and physical sensing parts have been established and tested. A numerical simulation model has been built to understand the signal transmission. The through-metal sensor has been used to measure temperature change in real-time.