- Yesterday’s report that the Horizon crew tried to activate BOPE before evacuating is very significant. We have now learned that the crew, the fail-safe closure mechanisms triggered by the power-loss and riser disconnect, and the ROV backup could not close the rams. Therefore, the absence of an acoustic backup system does not appear to be significant in this incident. An acoustic backup or any other type of backup would just be signaling the BOP to close, the same way the crew and automatic systems did, and the result would have presumably been the same.
- A smart guy in Houston (doesn’t want his name used) raised an interesting thought last night. If they had time between the first flow and the start of the fire, would they have been better off initiating a drive-off routine that disconnected the riser from the well and moved the rig away from the location? (Keep in mind that this was a dynamically positioned rig.) The fire would have been prevented or minimized, lives might have been saved, and the rig would not have sunk. Why not establish an escape option that takes advantage of a DP rig’s mobility?
- The same contact also suggested that continuous pumping of fire-water into internal compartments may have caused the rig to sink.
- Escape procedures and lifeboat issues have not received much attention to date, but are sure to be an important aspect of the investigation.
- MMS postponed the National SAFE Awards scheduled for Monday. This was the correct decision under the circumstances.
Morning Musing
April 30, 2010 by offshoreenergy
Bud's Offshore Energy (BOE) 
Hi,
On the comment on the drive-off option, or better to say the “drift-off”option. Is on option what needs to be installed on all self propulled or DP-drilling rigs/vessels. Normally a drift-off can be initiated by the DP-operator, the sequence normally is,secure the BOP – disconnect the riser, the vessels propulsion will go automatically go over on hand and the DP-operator/Officer on duty can navigate the vessel away from place of incident. (This sequence is one of the acceptance test in deep-water brazil).
That the rig has been”helped”sinking by fire-water is speculation, but certainly it need to have been a great impact on the bouyancy of the vessel. Note; the floaters where still in a good condition after the blast, only the topside was damaged and places of the deck where raptured. Normally the rig should have had more then enough floating capacity, to stay afloat. What I’m afraid of is, is during the evacuation a lot of waterthight doors have been left open to give the people on board access to get out of the rig. Now when putting water on the rig, and it’s open decks..it will not take long before the rig will be pumped full.
Good comment and thanks for your informed insights. Bud
When I heard th interview with the survivor, I was reminded of a few similarities with a shallow gas blowout that occurred in the Norwegian Sea (Halten Bank) in 1985. The rig West Vanguard (Aker H3.2) was drilling a pilot hole when they had gas influx into the wellbore. They were drilling top hole sections without BOP, but it was common to use the marine riser for these early sections at that time. The crew engaged the diverter, but it failed due to erosion after a few minutes, and the gas was spreading rapidly from the drill floor and subsequently from room to room in the deck box girder. An unknown ignition source set off a series of explosions. One person was never found, but the remining about 80 persons evacuated safely, mainly by 2 lifeboats, the sea was calm, and the fire “compensated for” the lack of daylight just before midnight.
The rig actually took some 8-9 deg listing due to fire water filling up compartments (in the columns?), but two crew members had remained behind the general evacaution and managed to move the rig out of the worst gas plume by releasing three anchor lines. These two brave men subsequntly climed down to sea wearing survival suits and started swimming in the direction of the standby vessel. They were picked up by fast rescue craft from the standby.
It was fortunate in this incident not to have more than one fatality (though in itself tragical), the rest were picked up by the standby vessel.
The fire raged for several hours and the gas flow for several days (I think), but there was obviously no pollution. The rig was salvaged and repaired and is still in operation.
Jan-Erik, Very interesting. Thank you for taking the time to share your insights. Bud