UltraMonit® In Situ
The UltraMonit® is an ultrasonic erosion and corrosion monitoring tool
providing real-time and online wall thickness data on subsea spools and
The UltraMonit® system uses an array of ultrasound transducers providing reliable high precision ultrasonic wall thickness measurements at selected locations. It is based on the well-established ultrasonic pulse-echo method.
The UltraMonit® system integrates with the subsea control system providing the operators with live wall thickness data.
Some key advantages are:
• Reduces or eliminates the need for intelligent pigging
• Real-time monitoring of the effectiveness of corrosion inhibitors
(feedback on corrosion inhibitor programmes)
• Benchmarking of intelligent pigging
• Improved pipeline integrity management on non-piggable pipelines
• Life extension and improved safety margins for late life pipelines
• Monitor weld/HAZ on pipe to show variation in corrosion rates
How does it work?
The ultrasound transducers measure wall thickness as a function of time and provide high resolution data on material wall loss. The sensors are installed directly on the pipe outer wall, or on top of the weld seam, before the pipeline or pipe spool is installed.
The figure to the right shows a subsea layout where the UltraMonit® typically can be installed. The ultrasound transducers are mounted in PEEK sensor housings, which are fixed to the pipe. Wall thickness is detected by pulse-echo ultrasound measurements, with the transducers immersed in a coupling liquid in front of the pipe wall.
A short ultrasound pulse is generated by the transducer, and echoes from different interfaces are recorded by the same transducer. The UltraMonit® consists of multiple ultrasound sensor module spread around the pipe, and each contains several ultrasound transducers mounted together with a multiplexer card and a temperature sensor. The transducer assembly is moulded into the same insulating material as the rest
of the pipeline.
Network and interfaces
All data is processed by the UltraMonit® subsea unit.
In addition, raw data can be transferred to topside. The data is communicated through the subsea control system via RS 485 or Ethernet using transparent link, OPC or Modbus protocols. As shown in Figure 2 the corrosion data can be presented in a simple table or a sector map in the platform control room. In addition,
wall thickness trend curves can be provided as shown in the figure to the right. The UltraMonit® In Situ gets its power from an external power supply (9-36 V), or alternatively from a battery pack.
How do you install it?
The UltraMonit® In-Situ is pre-installed on the actual
pipe joint or spool prior to pipe lay or subsea spool
installation. The UltraMonit® may be insulated to
avoid cold spots. A ROV connects the UltraMonit®
to the subsea control system using a wet mateable
jumper cable. All external cabling and electronics
are ROV replaceable. The UltraMonit® sensors
can be installed on top of FBE, 3LPP or other solid
homogeneous insulation materials.