This is news on Exxon’s Beaumont No 5 coker going down to repair a leak. I think it is good indication that both planned and unplanned downtime may be closer to that of 2007 than the historic levels due to all the project / upgrade work going on while normal maintenance work limps into the break between winter & spring peak transportation fuel demand periods.
The EIA has good article entitled ” Crude Oil : Lost & Found Capacity – see it at : http://tonto.eia.doe.gov/oog/info/twip/twip.asp
It shows graphically for both planned and unplanned downtime the sharp increase in total dowtime at nearly 2X to 3X normal for 2006 & 2007 compared to previous years. It points out that 2006 unplanned time is from the impact of the Hurricane damage late 2005 – May 2006 and that major portion of 2007 downtime was due to the Texas City explosion which remains partially offline even into 2008.
But no one doubts that the most dangerous times are during a startup or shutdown and those additonal stress on equipment and units already under long time operational stress can lead to later falilures. I personally believe that if you took a multiyear average on planned & unplanned downtimes and you could produce a ratio that would suggest that the more maintenance and project work you have the larger the potential for unplanned downtimes might be.
Obviously it wont be a predictor of one-off events like Hurricanes and Texas City explosions – but US is loaded up with upgrades and expansions and I believe the article is wrong to think that 2008 is going to be more like pre 2005 than 2007. I have posted the scheduled downtime outlooks for US, EU & Asia refineries & you can use it to make an estimate for 2008 on planned which I believe is closer to 2006-7 than to 2005.
But that is just one mans position – the article is good one either way.