Crude oil refinery reduces downtime and improves diagnostics and network security with control system upgrades and integrated asset management software.
In 2012, a major energy company’s oil refinery in California was producing more than 290,000 barrels of crude oil per day. However, aging equipment made maintaining this production capacity more challenging.
With operations running night and day, the oil and gas industry requires equipment that is not only reliable but also helps enhance worker safety and minimizes security risks. Diminishing the downtime associated with these risks becomes increasingly difficult as equipment approaches obsolescence.
With a facility footprint of over one square mile and more than 1,100 miles of pipelines, the refinery had an expansive control architecture, operating a distributed control system on top of more than 185 aging programmable logic controllers (PLCs).
Nearly half of those PLCs were legacy Allen-Bradley® PLC-2® and PLC-5® controllers operating for more than 25 years. This equipment rapidly was becoming obsolete or had already been discontinued, making replacements and repairs problematic for operators.
The aging PLCs offered limited diagnostic information, making it nearly impossible to tell where network issues were occurring. Troubleshooting often led to hours of unplanned downtime, as well as safety and security risks.
In addition, when operators were alerted of a lost signal there was no way to determine where or why the signal had been lost. They would have to call IT to find out the root of the issue, leaving equipment offline for hours while the technical support team worked to revive the network. With limited diagnostic information, it was difficult to determine whether the source of the network outage could pose a threat to worker safety.
The refinery also lacked a formalized process for making changes to controllers in the field. Individual laptops were used to manage programs and update controllers as needed. While these laptops were regularly backed up, without a central repository to store files and document changes there was limited insight into how, when or what changes were made.
Facility operators needed a way to easily manage and control assets, and address the obsolescence risks of the legacy hardware across the sprawling facility. However, all this needed to be done without causing additional downtime while the project was in progress.
Making the Switch
After careful consideration, the refinery turned to Rockwell Automation to design and install a future-ready infrastructure and improve configuration control while minimizing operational interruptions.
At the heart of the project was a massive PLC migration. With 185 controllers in operation, the company needed to develop a strategy to replace aging equipment without adding costly hours of downtime.
The Rockwell Automation team chose to take a phased approach to the project, upgrading the legacy PLCs in stages rather than replacing all the equipment at the same time. This would allow the refinery to continue 24/7 operations throughout the modernization process.
The company opted to replace the legacy controllers with an Allen-Bradley ControlLogix® platform. The new control system would offer tight integration between the programming software, controller and I/O modules, improving visibility into refinery operations.
The new system included Allen-Bradley Bulletin 1756™ ControlLogix I/O chassis-based modules. With the installation of the I/O modules, operators would be able to access comprehensive I/O diagnostics to help detect network failures both in the field and system-wide.
In addition to the PLC migration, operators at the refinery wanted the ability to troubleshoot the network without contacting the IT department while out in the field; they needed the network diagnostics available at the local HMI.
Rockwell Automation also installed Allen-Bradley Stratix® 8300 modular managed Ethernet switches. The Stratix switches were standardized across the field. This helped facilitate uniform configuration when placed into production and provided support as needed.
The switches offered a networked solution built on an EtherNet/IP™ network. With remote access to each controller, operators and engineers would be able to easily access diagnostic information from each controller.
Once the PLC migration is complete, the team implemented FactoryTalk® AssetCentre software from Rockwell Automation to improve the level of configuration control on-site. With a centralized tool for managing and tracking asset information, operators finally have a central repository for files and more insight into what changes are being made across the facility.
The new software created a formal procedure for change management and replaced the process of checking out individual laptops each time changes were made to controllers in the field. By securing access to the system and limiting network administrative rights, the software also helps mitigate internal security risks.
Fueling the Future
Since starting the project in 2012, engineers have replaced nearly half of the legacy PLCs in the refinery. While it is too soon to calculate the full potential of the migration nearly halfway through the project, the refinery already has seen substantial improvements.
With the ability to manage and control assets remotely, unscheduled downtime has been reduced from hours to minutes. Before the upgrade, operators would spend hours waiting for IT support to troubleshoot network issues. A more comprehensive network architecture offered more insight into network connectivity issues and allowed engineers to get the new controllers back online faster.
The FactoryTalk AssetCentre software has allowed operators and engineers to authorize users to access the necessary files to perform their PLC tasks both remotely and in the field. The software has also created an archive that has helped manage revision control.
As more of the PLCs are upgraded and brought online, the refinery will be able to use the software to archive the PLC and HMI files, and take full advantage of the disaster recovery features. The refinery is on track to complete the PLC migration within the next five years.
Learn more about FactoryTalk AssetCentre from Rockwell Automation.
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