Major oil company TotalEnergies has upgraded its operational technology (OT) network with infrastructure from connectivity services and intelligent networking tools provider Allied Telesis, as part of its plan to ensure legacy OT in its North Sea oil platforms is replaced by efficient critical infrastructure.
The new network comprises multiple dual redundant networks, interconnected among three oil and gas platforms. They serve over 400 nodes and the platforms’ distributed control system, emergency shutdown safety instrumented system, fire and gas safety instrumented system, electrical control system, multi-phase pump control system, and alarm management systems.
The legacy network has been experiencing component failures and concerns over availability of spares, as well as worries regarding support for the ageing infrastructure.
The upgrade project saw Allied Telesis work with its channel partner, control and safety systems specialist Process Safety Solutions (PSS), to install more than 200 items of hardware in 18 equipment rooms across three TotalEnergies platforms located approximately 500 km north of Aberdeen off the Scottish coast.
Because PSS had produced a detailed obsolescence study of the entire legacy Integrated Control and Safety System (ICSS) OT network and outlined requirements for a new network, Allied Telesis knew the upgrade would need to operate with many legacy systems while offering the advantages of current technologies in terms of ease of configuration and strong security.
The upgraded network would touch most parts of the platforms with multiple head end systems and 18 remote cabinets. As a result, enterprise-grade equipment with high levels of fault tolerance and resilience was a requirement along with backward compatibility, so that as new networking components went in, they could interoperate with legacy pieces yet to be replaced.
In terms of improving cyber security for the oil platforms, the Allied Telesis equipment now allows for system hardening in line with IEC 62443, providing enhanced security including VLAN segregation, port blocking and dedicated management ports.
There is also physical access control. Media converters and racks are utilised to extend the emergency shutdown safety instrumented system and fire and gas safety instrumented system peer-to-peer communication networks between the various offshore modules.
“A complicating factor for this upgrade is that we couldn’t turn all the old equipment off at once to install the new network in a ‘rip and fit’ upgrade, as this would black out the rigs, which was not an option,” said Myles Gowen, systems manager at PSS.
“We had to work in stages, one piece at a time, one switch, one bit of equipment at a time and incorporate backward compatibility in the design so that the new kit could speak to the old kit, and the old to the new. This meant supporting some unusual protocols.”