International refinery operator, North America
Refinery coke drums
$25 million savings to date
A leading Midwest refinery operator asked us to evaluate its coke drum repair procedures to reduce repair time. Under normal working conditions, a coke drum experiences high pressure and high temperatures, resulting in small cracks over time. These cracks require operators to shut down their facility to perform maintenance. Such downtime can cost hundreds of thousands of dollars. Our client was keen to find a better solution and asked for our help.
How we helped
On visiting the refinery to conduct a mechanical integrity evaluation, our consultants developed a new, more efficient repair procedure. This had immediate benefits, with our client reducing shutdown time by 13 days. This single event saved more than $10 million.
Besides efficiencies on shut down, we also developed an on-line inspection and repair procedure. This led to the discovery of an eight-inch coke drum crack. The crack was repaired on-line, enabling the facility to cancel the next two-week shutdown. With the new inspection and repair procedure, our client estimated avoiding three additional shutdowns, saving an estimated $15 million.
After this repair, we helped devise a comprehensive, real-time monitoring programme for our client. This work minimised the likelihood of coke drum cracking for further savings.
Our client’s real-time programme monitors stresses on, and temperatures of, coke drums. The data gathered using strain gages and thermocouples during operations is used to correlate with changes in process variables. From these results, we can guide the operator in making changes to the preheating and quenching procedures, decreasing localised thermal stresses on the shell and skirt to help prevent cracking in the first place.
We helped our client make ongoing operational savings by:
developing new, more effective repair procedures
recommending operational changes to reduce cracking
implementing monitoring to capture and understand how the ever-changing facility operations are affecting the coke drum and what can be done to minimise cracking.
To date, the operator has saved over $25 million.
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