Repsol has E&P operations in Ecuador covering 199 sq km (76.9 sq miles) in the eastern part of the country established through service contracts with the Ecuadorian government. These operations include two main production facilities known as NPF and SPF, with operations beginning in the plants in 1994 and 1997, respectively.

While still highly productive, the company needed to update its decades-old safety instrumented systems (SIS) in these facilities to bring the facilities into compliance with the company’s newly implemented internal safety standards. The aging equipment also presented obsolescence risks and lacked information visibility required to help plant workers effectively maintain them.

New safety standards

Repsol in recent years created and implemented a new internal safety standard for its E&P sites around the world. Based on the global IEC 61508 and IEC 61511 safety standards, the company’s standard was designed to help the company work toward its goal of zero accidents in all areas of its operations.

In 2013 the company conducted several types of risk analysis of its global industrial assets to identify its compliance levels with the new corporate standard. This included conducting safety integrity level (SIL) and hazard and operability analyses at the NPF and SPF facilities.

The studies helped the company identify the SIS upgrades that would be needed to bring the facilities into compliance with the new standard. More than that, the studies also brought attention to the obsolescence risks faced by some of the equipment used in the two facilities.

Hardware such as the PLC-5 systems that were in place in the two facilities was still operational and in good working condition. However, Repsol had limited spare parts available to support the systems, which could have resulted in a prolonged downtime event should a failure occur. Additionally, the aging systems lacked diagnostic information, which made troubleshooting and downtime resolutions more difficult for operations and technicians when issues did arise.

As a result, Repsol sought to migrate to an SIS that could bring its Ecuadorian facilities into compliance while also reducing downtime risks associated with aging equipment. The company also wanted the nearly monthlong migration to be carried out without interrupting production, which runs continuously at both sites.

SIS and network upgrades

Repsol worked with Rockwell Automation and Exida, an Encompass Product Partner within the Rockwell Automation PartnerNetwork program, to define and select the best solution for the new SIS at its NPF and SPF facilities.

The team selected an Allen-Bradley ControlLogixbased SIS from Rockwell Automation. From an implementation standpoint the system provided easy integration, not only with the PLC-5 that it would be replacing but also with the rest of Repsol’s existing installed base of Rockwell Automation equipment and other vendors’ equipment. This ease of integration reduced risk of downtime during the migrations.

“Sharing information across different vendors’ systems is possible but not always easy, and sometimes it requires that you bring in outside technical experts,” said Marcelo Villegas, project engineer for Repsol Ecuador. “That wasn’t the case with the Rockwell Automation system. It gave us a clean interaction between the different systems that we had in place.”

As part of the migration Repsol also implemented a new fiber-optic network for the communications between controllers and input/output (I/O) racks and used alarming and events capabilities within the new system to gain better visibility into performance and downtime issues.

Benefits

Because the NPF facility is smaller and has only about one-quarter the capacity of the SPF facility, Repsol used it as a proving ground for the first of the two SIS migrations.

The NPF migration was successfully completed in 21 days, and the team carried over key learnings from that project to the SPF migration. Despite the SPF facility being much larger, the team completed the migration in the same amount of time. Migrations at both facilities also were completed without interrupting production.

The new SIS meets Repsol’s new internal safety standard at both facilities. Furthermore, the systems are creating new opportunities for the company to improve reliability and productivity at both sites.

Replacing the decades-old SIS technology with modern systems reduced the risk of downtime that plagued both facilities due to a lack of spare parts availability with the previous system. Additionally, the new systems are standardized on the same technology, allowing the company to minimize its parts inventory.

Repsol workers also can now use alarms and events to access information about system performance to improve troubleshooting should a failure occur. Workers can even use real-time performance data to predict where failures are likely to occur to help avoid downtime events in the first place.

“We didn’t have any insights into failures in the previous systems,” Villegas said. “The new system allows us to monitor every part of the architecture, whether it’s the controller, the different I/O racks or a specific output signal. This can help us more quickly identify the root cause of a failure and in some cases anticipate where a failure is likely to happen.”

Looking to the future, the systems will offer Repsol greater flexibility for meeting safety requirements. Both facilities currently only have SIL 1 safety requirements, but the new SIS provides SIL 2 performance should it someday be necessary.

“By staying ahead of our current safety requirements, the Rockwell Automation solution prepares us for future expansion,” Villegas said. “These systems will help us get ahead of potential SIL requirement increases without another SIS upgrade in the future.”