The Pulse Monitoring System is an adaptation of the SeaDAQ subsea data logger technology to measure flow induced pressure pulses in a subsea pipeline. The pressure pulse can be identified by measuring the expansion of the pipe in the radial direction – almost like measuring the pulse through a blood vessel.
However, unlike the human pulse, this is measured on a 12″ steel pipeline, and the force generated by the pressure pulse only moves the pipe a few nanometers in the radial direction. This presents a number of challenges to the measurement system: e.g. how do we isolate the minimal acceleration of the pipe compared to the surrounding noise?
Innova addressed these challenges by combining high sensitivity MEMS accelerometer with implementing an advanced 24-bit analog to digital converter system with 12 parallel ADCs providing high resolution, high dynamic range vibration measurements. Parallel measurements mean that vibration data from multiple sensors can be obtained simultaneously. Combined with an innovative sensor clamp design where 4 sensors are mounted in 90 degrees around the pipe circumference and allowed to float freely when the clamp is attached, this is used to cancel out unwanted environmental noise and measuring only the radial movement of the pipe.
The use of parallel ADs allows for accurately timed measurements at different locations, providing data for analysis of pulse propagation through the system.
Using the SeaDAQ system’s advanced power management functionality, the Pulse Monitoring System were installed for several months on battery power, logging data at specific intervals.