01.09.2015

Monitor Vibration

Kjetil Nysæter, Area Sales Manager, with the next generation lightweight Subsea Vibration Monitor powered by an on-board battery or external power supply.

Pipeline failures can have serious environmental and economic consequences. ClampOn’s Vibration Monitoring Solution provides accurate measurements, which allow for safer production. “Production is often restricted if there is risk of vibration that may lead to fatigue. Accurate vibration monitoring allows operators to increase the production rate without compromising the safety of the installation,” says Area Sales Manager Kjetil Nysæter.

Statistics from the UK Health and Safety Executive show that vibration-induced fatigue causes 21% of all topside pipework failure in the UK sector. This is not directly comparable to subsea installations, though it is a fact that aging subsea structures and pipework suffer from fatigue,
often caused by vibration.

While there are many technologies available for topside vibration monitoring, only a handful of companies produce such products for the subsea sector. Using our experience and existing hardware platform as a basis, ClampOn has developed advanced solutions for permanent and temporary inspection-type vibration monitoring.

At the heart of ClampOn’s vibration monitor is a MEMS (microelectromechanical system) comprising a dual three-axis accelerometer, three axis-gyroscope, and magnetometer. This technology is the cutting edge of what is available in the market, and has the highest sensitivity and accuracy. At the same time, power consumption is low, the instruments are small, and they are unaffected by ambient temperature changes

MEMS (microelectromechanical system), a tiny chip that measures acceleration using accelerometers, and motion using gyroscopes

For new projects, it is common to incorporate permanent instrumentation on critical locations or design access for inspection type monitoring to be able to check the integrity of the pipelines regularly.

For long-term and permanent solutions, ClampOn utilises the same mechanical fixtures and instrument closures that the company has deployed subsea for the past ten years. With the sensor hermetically sealed in a titanium body, the expected lifetime is more than 30 years.

Stand-alone solution for rapid and pain-free deployment

Most installations do not have permanent monitoring options. When a vibration issue arises, this calls for quick mobilisation. To meet this demand, ClampOn has developed a lightweight, stand-alone solution for rapid and pain-free deployment. ROV operated mechanical clamps and magnetic fixtures enable retrofit installation of vibration-monitoring equipment on locations that would not normally be accessible.

ClampOn has performed multiple vibration monitoring jobs. All of them have been successful, and the feedback has been very positive. “One of our customers told us that he was amazed that less than three days after the call out to ClampOn, he was able to sit in his office watching live data from the subsea vibration monitor,” says Area Sales Manager Kjetil Nysæter.

Advanced computer simulation is important to identify where on a subsea structure or pipework any flow or vortex-induced vibration will occur, and where the best place for monitoring is. Simulation should also be used during the design phase to eliminate or minimize the risk of potential vibration. A combination of simulation and monitoring is the ideal solution. ClampOn’s preferred partner for simulation is Xodus group. Xodus group has a highly skilled team of experts on vibration simulation, led by Mr. Robert Swindell.

Plot example, which represent vibration force inn all three axis at different frequency bands