National Physical Laboratory

Sensor test for Stingray Geophysical

NPL completed a consultancy under the Measurements for Innovators (MFI) programme with the aim of characterising a passive optical acoustic sensor for marine oil and gas applications.

The fibre-optic array of Optical Sensor Units (OSU) is connected by armoured fibre-optic cable
The fibre-optic array of Optical Sensor Units (OSU)
is connected by armoured fibre-optic cable

The unique optical seabed seismic system, called Fosar® was made for commercial oilfield use by a company called Stingray Geophysical (which has since been acquired by TGS). The Fosar system consists of a passive, fully fibre-optic array of Optical Sensor Units (OSU) connected by armoured fibre-optic cable. The technology was originally developed in the mid 1980s where its small size, high sensor count and extreme robustness were attractive for anti-submarine warfare applications. The oil and gas industry is now benefiting from the development of this technology.

The Challenge

As a part of their development program, Stingray Geophysical wanted to carry out testing of a sensor unit at simulated ocean conditions to determine the acoustic performance of the sensor at various environmental conditions as well as monitoring the integrity of the device.

The Solution

To achieve this Stingray Geophysical required acoustic characterisation over a frequency range from 2,000 Hz down to the lowest frequency that we were able to measure.

The acoustic testing was undertaken at simulated depths down to 600m while at approximately 8°C using the unique test facility provide by the NPL Acoustic Pressure Vessel.

The Impact

The consultancy opportunity proved to be highly valuable to Stingray Geophysical.

Richard Luff, Operations Director of Stingray Geophysical, commented:

"Stingray Geophysical has been developing fibre-optic sensing technology for the permanent monitoring of undersea oil and gas reservoirs. As a part of our product development programme we approached NPL concerning a functional test of an optical senor unit (OSU) under increasing hydrostatic pressure. This test was necessary to prove that we suffered no degradation of sensor performance with depth. The consultancy service provided by the NPL Underwater Acoustic Laboratory allowed us to qualify our current sensor and housing design to water depths of 600 metres.

"We at Stingray would like to express our gratitude for the services provided by the NPL Underwater Acoustics Laboratory. Following a phone call to NPL, we were able to set up our equipment and carry out the tests in less than two weeks. We are extremely pleased with the rapid response of NPL and the quality of the facilities offered. In particular, we appreciate the assistance given in the trials. We are pleased to say that the trials went faultlessly and to be able to do all this under the Measurements for Innovators programme has been an additional bonus."

For more information, please contact Graham Beamiss.

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Last Updated: 7 Jan 2013
Created: 6 Dec 2012


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