Achieving continuous improvement in safety onboard aging brownfield assets is a significant challenge. Reducing the potential impact on operations by upgrading legacy equipment, such as fixed gas detection systems—central to people and plant safety and security—has been a key driver for developers bringing forward a new generation of technologies. Wireless systems will play a crucial role in mitigating the shortcomings of legacy cabled gas detection systems, as operations extend far beyond the design life of platforms in mature fields.
GS01, the wireless hydrocarbon gas detector developed by Dr?ger Safety’s GasSecure division, gives brownfield asset operators the opportunity to make significant improvements to personnel protection coverage while avoiding potential production shutdown disruption issues associated with working on aging wired systems.
The GS01 is an infrared gas transmitter for detection of flammable hydrocarbon gases and vapors in the oil and gas industry. Intrinsically safe and safety integrity level (SIL) certified, the transmitter provides completely wireless signal transmission and operates with a safe battery pack.
Cost efficiencies run as high as an 80% saving on the potential cost of tearing down an outdated system and replacing it. That number combines the savings made from the procurement, engineering, destruct and construct costs associated with the replacement of a wired system.
Where wired system intervention requires an operational shutdown of the asset, the associated costs for production operations are even higher. Those costs are a crucial consideration for asset owners, operators and managers working to eliminate shortcomings in legacy fixed gas systems as platforms and vessels enter a new phase of their operated life.
The GS01 system is capable of expansion without significant intervention. The lightweight device requires two 8-mm bolts for mounting and no cabling, allowing gaps found in platform gas detection coverage to be easily filled again without major remedial works being required. Site installation work, as well as the volume of planning required before installation, is significantly reduced as devices can be preconfigured and are entirely battery operated.
Each GS01 detector draws less than 5 milliwatts of power, meaning that depending on ambient conditions in the installation area, each device can run for up to two years without requiring replacement batteries. The intrinsically safe design allows battery packs to be replaced in a hazard area.
Installation in demanding conditions
Safety-related measuring points on platforms, FPSOs and other vessels are numerous and in some cases extremely difficult—if not impossible—to monitor using wired gas detection systems prevalent on such assets. This issue introduces coverage gaps.
GS01 wireless transmitters require no conduits or cable, which simplifies installation. In open space it has the capability to send data to an access point up to 500 m (1,640 ft) away, while the GS01-EA variant with extended antenna can be installed inside structures where signal transmission is normally impossible due to shielding.
For temporary applications (e.g., during maintenance work or exploratory drilling), GS01 can be integrated into existing safety systems. In technically complex installations, such as on the rotating tower of an FPSO, transmitter installation can be carried out simply and effectively.
Harsh environment deployment success
The system has been successfully deployed offshore Norway for a major national oil company and is in use on one platform in a field development, which first entered service about 30 years ago.
A network of 20 wireless gas detectors was installed in three fire areas affected by weather exposure, with one gateway (radio access point) per area.
Given the platform’s age, many add-ons have been integrated into its structures over time. Therefore, there are many obstructions, from heavy steel decks to machinery that would test the detectors’ radio communication systems.
The GS01 system’s gateways communicate to one ABB fire and gas node presenting the alarms and failure status to operators in the central control room.
At the point of installation, it was estimated that the project would expend 5% to 10% of the installation time required for a conventional wired detection system.
Additional tests showed that radio signal coverage was extensive. One gateway could cover most of the platform despite several detectors having been placed in challenging locations.
Ten of the GS01 detectors were installed shoulder-to-shoulder with the platform’s legacy wired gas detector to compare response times, and tests showed it was essentially equal for both detectors; however, the digital design of the GS01 gas detector gives a quicker reading on the correct level of gas.
Operational stability delivers assurance
Wireless gas detection systems are able to offer at least the same level of safety performance as traditional, wired systems housed in 4-20 mA cabling. This means that, without compromise to safety, they also can secure cost efficiencies in terms of removing the necessity for FEED, materials, man-hours and downtime required to install and commission a wired system.
Wireless surveys can be quickly and easily carried out to prove connectivity. The system can be built, configured and commissioned onshore, facilitating an onsite installation time of days rather than weeks, and can be achieved while the plant is still running.
Infrared sensor technology in GS01 uses proprietary micro-electromechanical systems (MEMs) optical filters. MEMs offer long-term stability and eliminate the need for recalibration of the detector, which directly reduces associated system maintenance costs. MEMs operate at three different wavelengths and include heated optics to prevent condensation in the sensor.
Cybersecurity through innovation
Concerns centered on cybersecurity resilience in vital utilities led to the expedient creation of a new regulation in the U.K. in the form of the Networks and Information Systems Directive. Emerging wireless technologies need to fulfill its requirements if assets in oil and gas are to be capable of being safely and securely operated. GS01 eradicates the weaknesses presented by aged wireless technology. The SIL2-capable device uses the ISA100.11a standard for its wireless communication, which provides additional assurance compared to other systems, such as WirelessHART.
A clear benefit of the object-based standard is the possible embedding of foreign protocols, including the SIL3-certified safety protocol PROFIsafe. In combination with GasSecure’s SafeWireless communication concept for fast and secure transfer of measurement data, this enables easy integration of the GS01 into safety instrumented systems delivering a fully SIL2-capable signal chain. Furthermore, the open ISA100.11a standard supports easy integration of other field devices into the wireless network.
Even in a non-SIL system, the device remains constantly visible on the system, providing optical and power diagnostics without negatively impacting the unit’s battery life.
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