Subsea monitoring outfit Naxys has gained access to top research facilities after being bought out by global giant GE.
Naxys’ work in the field of subsea monitoring systems led it to be snapped up by Measurement & Control, a business of GE Oil & Gas earlier this year.
Now the firm’s products, in wide use on the Norwegian Continental Shelf and elsewhere, are due to go worldwide and Naxys’ expertise given access to top of the range research facilities.
The company, employing 31 people at Hegreneset, Bergen, Norway was cofounded in 1999 by managing director Jens Abrahamsen. Early on, Naxys set out to focus on subsea hydrocarbon leak detection and vibration/condition monitoring of subsea structures.
A large focus has been on the technology of acoustic emission, where stress waves caused by the vibrating structures, misalignment of shafts, or escaping fluids can be picked up over a wide area by sub-sea acoustic sensors that are designed and qualified for 25 years of design life.
The received signals are then processed and the data is used to identify known failure or activity characteristics.
The company has also developed an electric monitoring system, employing sensors that measure underwater electric potential or stray alternating electric fields, emanating from subsea electronics equipment, machinery, and cables.
These can be used to determine the condition of subsea machinery and plants by establishing electrical signatures and monitoring electrical power.
When used in combination with acoustic condition monitoring data, the operator achieves very precise conditions measurements such as pump slip ratios (pump efficiency), where the remotelymonitored electric field is the applied frequency and the remotely-monitored acoustic field is the actual pump RPM.
“As subsea exploration and production increases, both in magnitude and in importance, so does the need for detecting leakage from sub-sea installations and monitoring sub-sea plant and machinery for possible malfunction,” said Abrahamsen, who has an MSc in hydrodynamics.
He previously worked for five years developing naval subsea defense systems, specifically surveillance systems with Geco Defence, and before that he worked for Acergy.
“Early warning of adverse subsea conditions is vital to avoid machinery breakdown leading to lost production,” he said. “Early warning of leakage is also necessary to comply with EU legislation.”
To test its equipment, Naxys built a 210m deep, deepwater testing station outside its office and workshop in 2009. It features a test template on the seabed fitted with the equipment to simulate hydrocarbon leakage and a docking station to accept deepwater test frames, lowered into position.
Today, Naxys’ subsea condition monitoring systems can be found on the entire Norwegian continental shelf, on wellheads, manifolds, production stations, and pipelines. The firm has three subsea monitoring units (subsea leak detection, subsea pump monitoring, and subsea vibration monitoring) installed offshore Angola on Total’s Pazflor field.
Following its acquisition by GE Oil & Gas’ Measurement & Control business , the firm is already working with researchers at GE’s Global Research Center in New York on the development of advanced subsea sensors.
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