The need to squeeze out the last barrel of investment in any oil and gas field has resulted in a global increase in life extension projects for ageing offshore oil and gas platforms. This has resulted in some extreme and demanding situations for gas detectors.
During life extension projects the fabric of the main structure of operational platforms will require maintenance or alteration. This will often require a rolling campaign of grit blasting over several months. This work will severely impact gas detection systems and specifically any open path / line-of-sight (LOS) detectors where the beam will be blocked. Operators need an alternative, robust and flexible supplementary gas detection system. The GasSecure GS01 has been tested specifically to meet this demand and with minimum budget impact.
Offshore life extension projects that need maintenance of the platform structure will require the use of sheeted habitats to enclose the work areas including those where grit blasting is taking place. These habitats interfere with the line-of-sight (LOS) open path gas detectors by blocking the beam and rendering them inoperable and unable to detect gas. The facility operator must mitigate this loss of gas detection by using suitable replacement systems as an additional layer of detection. However, as the alternate system is not intended to be permanent it requires some specific features to be viable. These include;
- Suitable for all indoor / outdoor hazardous area uses in an offshore environment.
- A technically approved and competent form of gas detection recognised by safety authorities.
- Wireless communications to a central monitoring unit.
- Cable free for convenient, flexible placement and to avoid cable checks and trip hazards.
- Long life battery (1~2 years) and preferably without sensor calibration.
Above all else the device must be able withstand the extremely aggressive environment created by the industrial grit blasting activities and still be able to detect gas hazards.
This is the scenario faced by oil and gas companies operating in the North Sea and why one specific client chose to evaluate the capabilities and resilience of the GasSecure GS01 wireless infrared hydrocarbon gas detector for their life extension projects.
To prove the GasSecure GS01 performance the operator constructed a realistic blasting cabin test enclosure from a modified Portacabin complete with a Cape blasting unit and 200 kg of Indian garnet grit. The GasSecure GS01 was placed directly in the grit blasting area with a wireless access point and control station mounted in a separate Portacabin approximately 10m away to monitor the gas detector parameters and any alarms. The trials were performed with escalating severity and involved the grit blasting of steel test coupons covered with epoxy paint system [IMAGE 1].
Image 1: Test enclosure for gas detector assessment during grit blasting
The first trial started with 90 seconds of blasting after which it was impossible to view operations through the cabin observation window because of the dust levels. After a further 195 seconds of blasting the test was terminated as there was zero operator visibility within the test enclosure. After the dust had settled the particulate build-up was observed [IMAGE 2] and the GS01 was tested in-situ with a reference gas of 50% LEL methane applied at 1l/min through a tube connected to the test port.
Image 2: Particulate accumulation on gas detector assessment during grit blasting
In the first trial the operating environment was considered very aggressive but despite the dust accumulation the GS01 showed no faults or error signals and responded to the test gas after the grit blasting process had finished. The second trial was considered to be even more aggressive with a higher and longer dust burden as shown in [IMAGE 3]. The GS01 responded to the test gas during grit blasting and generated alarms wirelessly via the remote monitoring station. After the tests the
Image 3: Successful gas test for detector during grit blasting assessment
“The (GS01) instrument is capable of gas detection in heavy industrial dust laden environments”.
Image 4 & 5: Clean optics on GasSecure GS01 gas detector after grit blasting tests
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For more information please contact:
Marketing Ian Mackay +44 7769 652003 ian.mackay@gassecure.com
Corporate Knut Sandven +47 9778 7465 knut.sandven@gassecure.com
About GasSecure
The Norwegian company GasSecure AS develops, markets and sells the world's first truly wireless optical gas detector for demanding industrial applications. The detector is based on innovative ultra-low power MEMS optical filter technology and has introduced a new level of reliability and flexibility for the detection of gas leakages and represents an evolution in gas detection. The totally wireless detectors increase safety and dramatically reduce costs for the oil and gas, petrochemical, marine and process industries.
www.gassecure.com