Oil Spurt

With new extraction techniques, improved tax breaks and the ever increasing cost of a barrel of oil – the North Sea is benefitting from a new growth spurt. In particular, subsea technology with tie-backs to existing platforms has provided a welcome improvement in efficiency.

However, many of the assets originally commissioned in the last two decades of last century have already exceeded their design life and are now being expected to operate for another 10, 15 or more years. This means that operators face huge challenges supporting and maintaining ageing systems architectures whilst trying to improve OEE and ensure safe operations.

Many of the systems employed when the assets were first commissioned no longer have a natural migration path. Some suppliers of the systems and architectures originally specified have been through takeovers, leading to product line consolidation. This presents a challenge for many operators - and an opportunity for a few control and automation companies.

Another change is that ownership of North Sea assets has dramatically changed over the last 10 years, with many major global operators selling off assets to a host of smaller operators not equipped with large in-house engineering teams. This makes the whole issue of controls obsolescence even more of a challenge.

Rockwell Automation has helped protect the technology investments of its clients by providing hardware/software migration paths and communications connectivity across generations of equipment. Plant as much as 25 years old and running on Allen-Bradley PLC5s & 1771-I/O can be readily migrated to the latest ControlLogix platform without rewiring and reprogramming.

Besides being the obvious choice for upgrading Allen-Bradley PLCs, ControlLogix is also a strong contender for replacing many of the obsolete legacy systems in the field. New ControlLogix systems, some with SIL2 rated safety control, are being used on asset upgrades for such applications as turbines, compressors and water treatment.

Connector kits are also available for many of the major non-Rockwell Automation legacy I/O systems. These allow, for example, the field wiring of a Honeywell DCS or an April PLC; or a Bailey DCS to be connected directly to an Allen-Bradley ControlLogix system without any rewiring. Some of these kits are available as products and others are used in Rockwell Automation engineered systems.

Rockwell Automation’s Oil & Gas Systems Engineering business is currently upgrading Drill Rigs, previously with Honeywell equipment, to its PlantPAx DCS using this connector technology. On another project, a whole series of April PB400 PLCs are being similarly upgraded.

Using ControlLogix on all the packaged plant on a platform means that the same controller is also inherent in the PlantPAx DCS that can be used for the process control. It all forms part of a single, integrated "distributed database”.

The lifecycle cost of this approach over advantages over traditional DCS and standalone PLC controllers is attractive – it resembles the open support model for PLC and SCADA, rather than the proprietary DCS system that was the energy industry norm.