How the diamond string cutter works – the objective is to get a clean straight cut. Picture dental floss wrapped around a spinning pulley – covered with diamond dust. The cutter moves along a track and is secured to the pipe to assure a clean straight cut – which usually takes a couple hours.
The issue could be that this technique is usually used to dismantle old wells- not active wells under pressure. As the string is cutting the pipe (currently around 11:15 pm (Eastern), it is now far enough along that oil is gushing out of the cut… it is totally flooding the ROV and obscuring vision. It isn’t clear if this will ultimately impair the ability of the string to cut. Also, as the cut gets near “the end”, there could be a violent seperation of the riser as it gets blown off the piece still firming on the ground.
It could be an interesting day or two :)
As of a bit after 1 AM, it looks like the diamond string cuttting has failed, and the CUT ROV may be headed for a scrap heap. I could easily see the thing having iced over with the hydrates and stopped cutting. There is no apparent activity. With the DOJ now suggesting criminal sanctions, I suspsect BP will now demand President Obama personally sign off on every time they pick their nose.
Another web site with a bunch of oil biz people confirms what John Batchelor had said. When the BOP tried to fire off, there was a 9″ Drill Pipe inside the 24″ casing (doing work down below). So you have a pipe inside a pipe in the riser. The diamond saw has to cut through both of them. It appears to be stuck at the moment.
The CUT diamond string cutter has been forcibly removed from the BOP… it is dangling from its tether apparently lifeless and non-functional