Passive Wireless Sensor Tags Benefit Energy, Aerospace, Transportation, & Industry

The world's first Passive Wireless Sensor Tag (PWST) workshop was held July 27 & 28 in Houston, Texas, and brought together subject matter experts from around the world to discuss how wireless sensors are connecting the physical and digital worlds. Representatives from NASA, the US Department of Energy, British Petroleum (BP), Shell, GE, Boeing, the International Society of Automation Communication Division, as well as numerous universities and companies were in attendance.

I not only had the privledge of presenting, but saw some impressive demonstrations of passive wireless sensor technology and learned how those technologies are being used today and how they will be used tomorrow. What was most surprising though was hearing the presentations from the big companies and government agencies who are making significant investments in wireless sensors.

"Passive Wireless Sensors may save BP more than $50+ million a year", according to Dave Lafferty, BP Chief Technology Office, and workshop host. The potential applications of PWST are numerous. Wired sensors, or generation 1 sensors as BP calls them, cost BP an average of $10,000 a piece to install. That may seem extraordinary, but not when you consider the cost of wiring safely. For example, running conduit in concrete across a large facility for the wire to be housed properly is challenging. Wireless Motes (generation 2 sensors) reduce that cost to approximately $1,000 per sensor. Active sensor tags (generation 3) are around $100 per sensor. What BP really likes is Passive Wireless sensors (generation 4) cost about $10 per sensor.

When you consider how many wireless sensor tags BP needs, you'll understand that BP isn't just trying to be frugal. BP needs to monitor the corrosion that occurs under insulation, where you can't see. There are literally millions of locations in BP's plants, refineries, and infrastructure. Wireless sensors can measure pH moisture, oxygen, and actual corrosion on a more frequent basis and more accurately than a routine visual inspection, resulting in safer facilities. Wirelss sensors are required because it is simply not feasible to install wiring and conduit to all of these locations.

“We boil oil for a living in our processes”, explained Lafferty. Refining uses large amounts of energy, and requires flames, to produce product. Having a better understanding the health of those flames can increase yields and decrease costs. Refining uses flares to remove waste product under “upset” conditions. Having passive wireless sensors for better monitoring of those flames can improve safety.

Knowing the location of our personnel in a “Heavy Metal” canyon of steal environments is important, but knowing that the person is “OK” or just been exposed to gas is more important. Using Global Positioning System or GPS is fine when there is a clear line of sight to the open sky, but when a person goes inside a well/pump house or working in an industrial plant, they need to know where there are inside. There also needs to be a balance of personnel privacy and security.

Mr. Lafferty talked about how wireless sensors can be used to monitor rotating equipment, including temperature, pressure, vibration, and power consumption in environments where it is hazardous for people. Abandoned wells have limited access, yet need to be monitored for up to 50 years. Using PWSTs to ensure environmental integrity issues, such as the integrity of the cement, casing, and the production tubular inside are also needed.

According to Mr. Lafferty, the key challenges for passive wireless sensors include:

• Standards: BP doesn’t want a different reader for every tag
• Read ranges: Minimizing the infrastructure in hazardous locations is important. Passive wireless sensors that can be read simply by driving by is ideal.
• Security: ensuring the sensor data can only be used by authorized personnel
• Access to locations where sensors need to be installed such as downhole, hot locations, under insulation, etc.
• Sensor type: measure the right thing (measure corrosion vs. pH and moisture)
• Price

There is no question that passive wireless sensor technology is beneficial to BP, industry, and everyone. In our next edition, we'll continue to explore current and future applications of PWSTs in various industries including commercial buildings, industrial settings, transportation, and aerospace.

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