BP Uses RFID Sensors to Track Pipe Corrosion

By Claire Swedberg

Jan. 31, 2011—Oil company BP is installing a corrosion-monitoring system for steel pipes at its 11 refineries around the world, following several years of testing the RFID sensor system at two refineries to track the corrosion of the metal walls of its oil-bearing pipes. The solution, provided by Permasense—a firm launched by researchers at Imperial College London—allows the oil company to attach the battery-powered wireless sensors to the pipes' exterior, thereby enabling it to remotely measure the thickness of each pipe's walls.

BP first approached Imperial College London for a system that would allow the company to track the condition of its refineries' infrastructure. The research team developed and tested battery-powered waveguide-mounted sensors—for which there are several patents pending—that employ ultrasonic technology to gauge the exact thickness of pipe walls, and then utilize the sensor's built-in radio chip and antenna to transmit that sensor data, along with a unique ID number, via an active 2.4 GHz transmission with a proprietary air-interface protocol.

The Permasense RFID sensor, encased in orange plastic, is mounted to a pipe's exterior.

Oil companies, especially those with an aging infrastructure, can find it challenging to monitor the quality of pipes that carry oil at wells and refineries. Crude oil is highly acidic, according to Peter Collins, Permasense's CEO—and is becoming more so as companies drill deeper wells that can affect oil quality—and can thus corrode the pipes through which it travels. It can be difficult to measure how badly a pipe has corroded, and the speed at which such damage is occurring. Traditionally, oil companies manually inspect their pipes at refineries by shutting down the pipes in question, using an ultrasonic device to measure the thickness of each pipe's metal wall, and then manually recording the results on a spreadsheet.

The process is costly, however, because a refinery's operating units must be turned off in order to accomplish the work. What's more, since manual testing is conducted only once every few years, it does not provide as much data as many companies would like. In addition, Collins says, such testing is prone to error, since it can be hard to identify the exact section of pipe on which a test is being carried out, making it difficult to compare the results of tests previously conducted on that particular pipe. And errors can be made when manually recording data as well.

In 2006, BP approached Imperial College London for potential solutions. Researchers at the university began developing a wireless system to measure pipe walls while the refinery remains in operation, and then wirelessly transmit that information to a gateway, via a mesh network of RFID sensors. The research team tested the system, and built software to capture the measurement data and display it for end users. The solution was first trialed at BP's refineries in Cherry Point, Wash., and Gelsenkirchen, Germany.