Equipment inspection and monitoring for any signs of internal corrosion is the key for safe operation of the Oil and Gas infrastructure regardless it is upstream or downstream, onshore or offshore field developments. To help operators to avoid an uncontrollable release of a flammable fluid, that can be catastrophic (shattering business reputation and ability to continue in the market), Ultrasonic Thickness Measurements (UTMs) have been used.
A state of the art Risk Based Inspection (RBI) plan for internal corrosion monitoring will be based on a combination of intrusive devices like coupons and probes, with Non Destructive Testing techniques like UTMs, Radiographic, intelligent pigging. Selection of techniques, scope, frequency and quantity of devices is a tight compromise between risk, effectiveness and cost. In the case of UTM’s, which is the “spinal cord” of any RBI, the issue has always been cost of crew deployment and repeatability of data in order to have a reliable historical data of equipment being inspected.
Now, a new application of a patented technology used to produce UTMs, known as Wireless and Non Destructive (WAND) system, which consists of two parts – a compact, battery-free ultrasonic sensor and a handheld probe is available. The ultrasonic sensor is entirely passive and can be permanently installed onto a structure being monitored. The handheld probe powers up the sensor by non-contact inductive coupling when it is brought nearby, even if the patch is under other material (e.g. an insulation or composite repair). The sensor then sends out an ultrasonic wave into the structure and detects the received signal. This is then transmitted back wirelessly to the handheld probe where the signal is analysed providing the thickness of the structure. As the passive wireless sensor is permanently installed, and the repeatable UTMs can be achieved within a second, WAND system can be used to increase the accuracy of UTMs, and reduce the time to take the measurements, and consequently improve the integrity and productivity while increasing safety of operation.