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2018.09.12 Aggreko

Unit Decoupling - Keeping Production Going During a Turnaround

Shutdowns and turnarounds are an essential part of the production process. If they’re not carried out properly, it can lead to loss of revenue for your plant and the oil and gas industry in general.

But how can you effectively plan for a successful turnaround? And how can you execute it in a way that doesn’t slow down output or put a strain on cash flow? These are all serious questions that maintenance managers face when met with the prospect of having to shut down their plant for planned or unplanned downtime.

If you’ve already carried out a turnaround, you’ll know that you need to think about the short-term results as well as planning for the future. Without proper planning, your plant won’t be able to run at full capacity during the turnaround which, if it goes on for too long, can have potentially devastating results.

If that sounds scary, don’t let it put you off. Turnarounds are essential to the long-term vision of a plant. Without carrying out regular maintenance and repairs, you’re depriving your site of continuous investment which, over time, can lead to unreliable operations that can hurt your business and revenue.

The most successful turnarounds keep production moving along as normal while maintenance is being carried out. Designing and implementing unique solutions that cater to the needs of each and every plant helps individual sites keep operations running at full capacity, but when it comes to unplanned downtime, like equipment outages or natural disasters, there’s not enough time to sit down and think about the best solution.

This is why many plants and refineries call on the help of experts to help them in their hour of need. Rather than stalling operations to come up with a plan-of-action in the moment, they hand over the problem to an expert who can quickly design and install a solution while processes carry on as normal.

Keeping Coker Production Levels High During a Six-Week Turnaround

Take one large US refinery that was scheduled to run a six-week turnaround. The site itself converted over 300,000 barrels of crude oil into motor gasoline, jet fuel, and diesel fuel every single day, so slowing down production for six weeks would have at least made a serious dent in output and revenue, if not shut the site down entirely.

The team at the refinery wanted to fix an outage in its coker unit without grinding production to a halt in the upstream units. The worst case scenario would have been shutting down the entire site for the duration of the turnaround, which simply wasn’t an option for a site with such a huge output.

The Challenge
We were faced with the challenge of keeping the crude and vacuum units running as normal even though the coker was out of action. This meant cooling the 600F VTB to a more manageable temperature so it could be shipped out to storage tanks while the turnaround took place. By doing this, operations at the rest of the refinery would run as normal.

Our Aggreko Process Services (APS) engineering team were called on to design a solution that would improve operations while also tackling environmental concerns that had been raised by customers.

The Solution
APS put forward a solution that would cool the VTB stream to a safe enough temperature for storage before exporting it on barges. We used heat exchangers, cooling towers, and cooling water pumps to cool the VTB and used Diesel as a cutter stock to reduce the viscosity of the stream. When the turnaround was complete, we shipped the VTB back in for processing before starting up the coker. This time, we integrated condensed steam to make sure the coker feed rates were maximized after its downtime.

It was a complex process with many different moving parts, but our expert team was on hand to provide customized solutions every step of the way. It was essential for the refinery to remain operational and at full capacity during the turnaround to avoid any serious loss in revenue and unhappy customers.

The Impact
As a result, the refinery reaped huge economic benefit without having to splash out on equipment for future coker outages - something that might happen once every four to five years. Instead, they took advantage of our rental units that we can deploy instantly to avoid any downtime at all. 

Keeping production running as normal during a turnaround plays on the mind of every site manager. Without regular maintenance, equipment can start lagging and suffer from unplanned outages, which means turnarounds are necessary for helping a refinery thrive both long-term and short-term.