Ultrasonic testing (UT) and nondestructive technology have been used to test the integrity of tank welds for several years. More recently, the technology has been reengineered in order to distinguish between tank and pipeline liquids. These sensors can differentiate between many common hydrocarbons and fuels, ensuring the quality of product liquid whether it is contained or transported.
New sensor technologies have redirected how sensors are being used. During the Gulf Wars, sensors were used to detect suspected chemical weapons within enemy combatants' artillery shells. Now, the technology has been repurposed to be used in the oil and gas industry to monitor tanks, pipes and their contents.
The technology is based on the principle that all liquids have a unique and identifiable fingerprint. Over 250 liquids have been categorized, including most of the important petrochemical liquids. The precision of the ultrasonic fingerprinting technique is accurate enough to distinguish between 93 octane gasoline and 91 octane gasoline from the exterior of a tank or pipe.
With the corrosive nature of crude and fuels, the ability to monitor fill levels and contents from the exterior of a tank gives it a competitive advantage for maintenance as well as an instrument to monitor the tank fill level. For automated overfill prevention systems, sensors are utilized on the exterior as an alarm initiator as well as a switch for an overfill protection valve. Further, all messages can be accessed remotely through WiFi from outside of the tanks.
UT sensors are installed on the exterior of a tank shell, greatly simplifying the maintenance procedures throughout the service life of the tank and sensor. Rather than having to perform a confined space entry necessitated by interior tank level sensors, the UT sensor allows for full circuit performance testing without the OSHA permitting process.
If the underside of a tank is accessible, such as in a bullet or spherical tank, the UT sensor can be used as a continuous level monitoring sensor. Further, vapors, foam and waves can cause poor response reliability from optical sensors; some of these issues related to optical sensors could be reduced with modern UT technology.
Additionally, with traditional cylindrical tanks, several sensors on the sides near the bottom can be used to determine if another fluid is present, such as water. If a tank is accessible along its vertical axis, an operator could move up and down the tank shell with a handheld sensor to determine a water line or if sludge is present. A drop probe can also perform the same results internally as a probe is lowered and the fluids are identified in real-time.
The drop probe can also act as an IoT device and continuously monitor the condition of the fuels in the tank. A fingerprint profile can be taken as the fluids enter the tank, and readings can be compared to the original status. As diesel fuels change to greener fuels with less sulfur content, microbes, yeast, bacteria and molds can flourish and potentially damage the integrity of the tank and injectors. The probe can be pulsed on a consistent time schedule, and an industrial IoT application can be mapped.
Other applications could result as a third-party validation for audit, risk managers and traders at month-end to verify contents and volume. Certainly an oiltech environment of monitoring assets and inventories is within reach with large data analytics.
For more information, visit www.perceptivesensors.com.