Monitoring system protects huge gas terminal

Edited by the Engineeringtalk editorial team Jan 8, 2008

Total EandP UK intends to use the scalability of CitectScada to get another 25 years out of the St Fergus Terminal.

Total EandP UK has installed a 10,000-point CitectScada system to provide monitoring - with full dual redundancy - of the control and safety systems for the giant St Fergus gas terminal in Scotland.

The Terminal plays a key role in supplying Britain's energy needs, receiving and processing up to 20% of the UK's natural gas requirements from some 20 fields.

"The Olympic Dam project in Australia was the major reason why we specified Citect Scada for this project", said Rob Sidebottom, Total EandP UK's Senior Systems Engineer.

"I had visited the dam and seen the massive 40,000-point CitectScada system that it employs for monitoring and control".

"This scalability - the ability to expand the Scada system seamlessly, easily adding servers as the need arises - was just what we were looking for to meet our objective of achieving 25 years more life from the St Fergus Terminal".

"We also required inbuilt dual redundancy in the Scada platform and the flexibility to provide emulation of the trending and alarm functions of the previous Scada system, to avoid problems of safety and retraining of our operators; CitectScada provides us with both of these facilities".

Total EandP UK, headquartered in Aberdeen, is the fourth-largest operator in the UK sector of the North Sea, in terms of production and reserves.

The St Fergus gas terminal on the north east coast of Scotland is part of the company's onshore operation.

Recently, the terminal was upgraded and as part of this project the Scada system that had served the terminal since the 1980s was replaced with CitectScada.

The CitectScada system sits above the Terminal's safety and control systems, monitoring all pipeline telemetry from a dozen feeder platforms, the flow rate, pressure and composition of the gas and also the control systems of the terminal as the gas is blended.

"We can adjust hydrocarbon levels for gas sales, monitor metering systems and perform data gathering, CitectScada puts it all together for us, providing all the required data in one place", said Rob Sidebottom.

"In addition to the benefits of scaleability and centralised data gathering, Citect Scada has also enabled the St Fergus Systems Engineers to take the cost out of the operating interfaces to the Terminal's safety and control systems".

"CitectScada is an engineer's Scada, which means that we were able to pull it apart and reconfigure it just how we wanted it", Rob Sidebottom said.

"We configured the system to emulate the trending, alarm and reporting functions of the previous Scada system".

"This avoided problems with safety and operator retraining, as the new Scada system provides the same screens as before".

"As a result, the operators were comfortable with the new system from day one; they saw nothing different to what they had always seen".

All 10 telemetry links and clients switch automatically and seamlessly in the event of failure of the primary server.

This safeguard is easy to achieve with CitectScada.

The system is designed with DCS- style multilevel redundancy, which is easy to configure and can be incorporated at all levels.

The significance of this for the user is the ability to tolerate hardware failure anywhere in a system, with no loss of functionality, performance, communication or system reliability.

"The success of this project has tremendous cost-saving implications for the oil and gas sector", said Paul Hurst, MD of Citect UK.

"It means that production and receiving facilities, whose futures were questionable due to the looming obsolescence of their current Scada and DCS systems, can remain productive for many more years to come".