Bridge to reliability

Gregory Hale

January 1, 2015

New age technologies block failures, and boost bottom line. Gregory Hale reports.

 

Every minute counts these days. The right decisions hinge on responding to issues before they become big, costly problems. The idea of equipment reliability is becoming an even more vital factor offshore.

This is why Shell created a team of engineers at its Upstream Americas deepwater headquarters in New Orleans overseeing 300 wells and about 12-13 main platforms in the Gulf of Mexico. They act as a bridge between platform operators running equipment and problem-solving engineers working on specific fixes and projects. The goal is to catch and fix small issues and alert those on the platform when they first crop up as a seemingly innocent bit of data before they become an issue.

“They are monitoring the rotating equipment and also some of their process equipment and looking for various leading indicators of degradation of equipment health,” said Bart Winters, product director for asset management solutions at Honeywell Process Solutions (HPS).

“They are seeing significant savings by being able to set up monitoring systems, like in the case of turbine exhaust gas temperature, that look for a sudden rate of change in the exhaust gas temperature. They will look at the last month average and compare that to the last 15min average and if they see a spike or a sudden change, that will trigger a surveillance task and a group of engineers comes in and investigates what might be causing that sudden change. Preventing a catastrophic compressor failure is worth about $4 million to them. In another case if they trip a compressor and have an event flaring for a four-hour period in downtime, it can save them multiple millions of dollars.”

Tom Moroney, manager of deepwater technology and geosciences at Shell spoke at the Honeywell User Group in June 2013 about the hike in technical and business complexity along with the workforce demographics and techniques on utilizing the resources they had to the optimum potential. That is where Shell’s Bridge team comes into play, so they can use automation technology to fix the small problems.

The use of the reliability technology helps alleviate the problems that operators have learned the hard way.

The new technology allows them to configure their systems to understand where past problems cropped up. “They are continually adding additional rules and algorithms to monitor and look for different kinds of or new conditions,” Winters said.

Remote reliability

Monitoring systems is not just a one person proposition, and as Shell determined, it takes a large cast. That is why remote monitoring is playing a bigger part in the reliability picture moving forward.

“We are doing two deployments in the North Sea and both of those are moving to a remote operations scenario,” Winters said. “Their goal is to reduce the amount of bodies on the platform, one of the implications is they will have fewer maintenance people on the platform. When they are sending someone to the platform they can know which potential instruments are having problems, and what pumps are having problems, they can be more proactive around that and do better maintenance scheduling. Technology is bringing in health information from the smart instruments, electrical systems, rotating equipment, and choke valves. That is one way to be more proactive around optimizing the wrench time when going out to the platform.”

The whole idea behind remote monitoring of equipment on the platform is to head off any issues for the critical assets.

“What you are able to see is a rate of degradation on any of the equipment on what you characterized as the failure modes and how you have characterized the degradation mechanisms,” said Stan Grabill, principal reliability consultant at HPS. “So, it is not just seeing it hours before it fails, but rather getting early indications or early event detection. In some cases we can have an intervention without severe degradation or can recover the degradation with some proactive maintenance. You can accumulate this information across an array of assets whether they are electrical rotating machinery, heat exchanger performance, where you get input on performance you can see anything that is starting to go south on you. The software is set up where you can see the degree of severity and the degree of degradation as well.”

Reliability trend

Right now, equipment ends up instrumented for two things: safety, where it connects to shutdown systems, and for control. There is significant amount of instrumentation already on the equipment, but one trend is seeing additional instrumentation for maintenance and reliability.

“The challenge is how do you pull all that disparate data as it relates to the performance and health on a piece of equipment and translate it to what the real-time health indicator is for that piece of equipment,” Winters asked.

“You need a central repository and a focal point for bringing that data in to assess the overall equipment health,” he said. “In the past you would have a vibration monitoring system that was separate from performance monitoring, which was separate from the control system. If you had high vibration, the vibration tech would not know what the compressor or pump was doing at the time of high vibration. Having it all together in one place you can see that yes, I have high vibration but I was running the unit hard so I can understand, or we had low flow, which means I had a cavitation issue.”

Program fundamentals

It is fundamental to have a methodology to determine criticality of equipment and your system in order to have a good reliability program.

“Regardless of the asset, whether it is instrumentation, process equipment and rotating machinery, there needs to be a way to determine criticality,” Grabill said. “Criticality sets up the priority in which you going to put together your reliability strategies. Criticality can come in different ways, there is a structured way of doing that by virtue of understanding the influence of each asset on safety, environment, production, volume, cost to maintain, and yields. There are a number of factors that can place in the criticality equation with the number of influences it has on the business and safety. The second thing is to take the criticality and figure out what to do with it.” That is where the user understands the failure mode.

The next move is to figure out what equipment to build the reliability strategy around. “I will build these strategies from maintenance analysis, root cause from past failures, and from just common sense,” Grabill said. “Once you understand the failure modes, you ask if you can afford to put the mitigation strategies in place, like real time condition monitoring, preventive maintenance schedules, operator monitoring. There is a cost benefit to each one of those depending on the impact of the failure modes to the business and the longevity of the equipment. Once I have the failure modes identified and the strategy built I have to implement the strategy, which can be complex. What you are doing is transferring the failure modes into actions.

“Get the work process around to take the failure modes with the criticality and the degradation signals and put them in where we can build some intelligence and experience into the system, then we can send a signal to the operations, reliability and maintenance guys to say I have critical equipment up there, but what is the most critical impending degradation taking place that I need to pay attention to today, or the next week? That intelligence needs to be built into this whole work process.”

Understanding the reliability equation that allows equipment to communicate the nuances of the dynamic offshore environment means engineers can make decisions before small problems escalate.




Gregory Hale
is the Editor and Founder of Industrial Safety and Security Source