Gryphon 'A' FPSO - Major Incident in North Sea

Just received this e-mail describing a Major incident with a North Sea FPSO (Floating Production Storage and Offloading facility - basically a fixed ship with top-sides processing plant). I understand it occurred 9 days ago, but I just received the mail - so here goes:

Subject: Extract from E mail ref Gryphon

still under partial emergency status.

"Lost heading last Friday and went broadside into bad weather.
Then lost both turbines followed by all power.
We did a few 21 degree rolls and snapped four anchor chains.
Drifted 180 metres off station and ripped all of the Gas Lift Risers clean out of the bottom of the ship. You should see the mangled pipework in the turret...holy f**k..!!
Gas cloud detected but quickly cleared, probably because the 11 gas lift risers were disappearing down the I-tube to the sea bed..!!
At this point we had contacted the authorities and were down manning by 70 personnel to 40.
RAF Sea King, the Coastguard helicopter and two Scotia emergency helicopters lifted all safely to the Beryl platforms.
Also had an AWAC overhead checking for oil spills etc. Fortunately not spilt a drop.

We have since deployed four tugs to hold us stable, initially by pushing us round I believe, but now we have connected two of them FWD and Aft for emergency heading control. The tugs are monsters, supposed to be the biggest in North Sea waters.
Also we have three anchor handling ships here along with two DSV's. A fair selection of Marine hardware turning up now.
ROV's in the water have fed back that we have wrecked the sub sea cluster. Chains wrapped around risers, riser bases ripped clean off the sea bed, some turned upside down mangling some of the flow lines, we managed to move one of the riser bases 70 metres..!!
The anchors are in all kinds of incorrect locations, two of the chains have actually crossed over!, one is wrapped around the riser arch, with as I say, four of them with snapped chains. The thing must have been doing pirouettes..!!
Yet to finish checking the risers, but apart from all of the 11 gas lift risers being ripped clean out we fear we have damaged others.
We have also sustained damage to the chain fairleads under the turret which is a very difficult place to put ROV's and divers so sounds like Dry Dock.
Presently stable, with full power and DP control, but should the weather pick up we could be in trouble again, hopefully the tugs will hold us.
Only 40 of us on board, me being  
 
 Not feeling brave about that, but feeling it's time I changed my f**king career..!!" continued.........
 

continued........

We have all seen some scary events over the years, but this is up there with the best, if that gas cloud had ignited it would have blew the middle right out of the ship.
 
So thats the sad state of Gryphon just now, maintaining a low POB for now until we can reconnect the anchor chains etc. then we plan to start flushing the risers and probably disconnecting them. All is still very unsure though as we are still under Emergency Aberdeen Control even as we speak. Bits coming in all the time, and all not good news.
 
I can't believe the amount of damage we have done, you couldn't have managed to do it if you wanted to..!!

end of e-mail message.

I am searching online for updates to this story - will post info as I find it.

PEACE,
RK

Just read a few reports in the media.
The weather must have changed very suddenly for something like this to happen. I see it is a Maersk operated vessel too.

I hope someone wasn't asleep at the controls. There are saftey protocols for this type of thing - they should have been prepared, seeing as they train for this sort of thing.

thought it would help, here are a few of the news links to this.

www.eveningexpress.co.uk...

af.reuters.com...

online.wsj.com...

luckily there is no reports of leakage

MAIN FACTS:
-The Gryphon Floating Production Storage and Offloading (FPSO) vessel is stable, all wells have been closed in and no oil spill has been seen.

-Work is continuing to secure the FPSO permanently, assess the damage done and plan for future repairs.

-The FPSO was shut down last Friday morning in heavy storms during which four of ten anchor chains broke, allowing the vessel to move off its position.

-All wells were immediately closed in and subsequent surveys from planes, vessels and remotely operated vehicles under the water confirm no oil was sighted.

-Seventy four non-essential staff were evacuated to a nearby platform and 43 essential crew members are currently on board. Two crew members received minor injuries. The FPSO was stabilised within minutes of its moving off position.

-The FPSO vessel is stationed above the Gryphon, Maclure and Tullich oil and gas fields. A complex piping system runs from wells on the seabed up to the FPSO.

-Gross average daily production was projected to be 18,400 barrels of oil a day in 2011. Maersk Oil's share of this production would have been 14,500 barrels of oil a day.

-Technical teams have attached two tugboats to secure the vessel and allow anchor chains to be reconnected to the anchors. Assessments are being made of the damage to the FPSO and the piping system connecting the wells to the FPSO.

-A separate investigation team is identifying the exact sequence of events, which lasted for around ten minutes, and its causes.

reply to post by Bagel


Bagel,
I doubt very much that personnel were to blame for this incident. It is a fixed installation, that means that it is permanently anchored to the sea bed by a number of chains (10 I think) and 4 of these snapped during the storm.
It appears to have been very close to disaster considering the witness account of a huge gas cloud which thankfully did not ignite.

PEACE,
RK

some educational info about the Gryphon Floating Production Storage and Offloading (FPSO) vessel:

The Gryphon FPSO is located 175 miles north east of Aberdeen. The vessel is 260 metres long and 41 metres wide. It is capable of storing 540,000 barrels of oil. The water depth around its position is 112 metres.

www.maerskoil.com...

reply to post by bladdersweat


Bladdersweat,
The report that you pasted appears to me to play down the incident. I do not think we can expect these risers to be connected and production to resume anytime in the near future. This was a major incident and will require major repair works. To my knowledge, this is the first time a North Sea FPSO has broken its moorings.

I worked in the North Sea for many years and have been on this FPSO a few times the last time was 2003 when it was operated by Kerr McGee. The vessels classification status is/was with Lloyds and will likely be suspended pending an extensive topsides/hull and sub sea survey of vessel, moorings, risers and sub sea template etc and this will take many months.

From the damage report contained in the original e-mail of the O.P I would expect that
all riser pipelines will need to be recovered and new ones fabricated. Much debris and wreckage is ontop of the wellhead and this will have to be removed by divers/ROV's. This was a short step from being another disaster and it was caused by adverse weather this time.

Thanks for the additional info

PEACE,
RK

reply to post by Rigel Kent


Rigel,
I know what you mean about the moorings. Having worked on the vessel yourself, you know they get at least two weather updates every day. The FPSO's advantage is that it can de-rig before heavy weather right?
Why didn't they see this weather coming?

I guess it is possible that the weather was manageable, but their was poor maintenance of their anchor moorings, which then failed.

reply to post by Bagel


Bagel,
No they cannot de-rig for bad weather, they are pretty much fixed.
When the FPSO's working period at the location has finished (i.e. when the reservoir is no longer producing or the owner wishes to move it) it can all be derigged but this is a very big operation and takes a few days and a lot of planning.

What makes you think that the moorings were poorly maintained? This vessel had 10 anchor chains connected to its midships turret and the design ensures that the whole vessel can rotate around that vertical axis as a result of wind and current direction.

These chains are big (each has a load test of about 1250 Tonnes).

PEACE,
RK

S&F......thanks for the update, I hope this is over quickly....they said there was a gas cloud? Where did it come from? (or did I miss something)

Is the the one?

[atsimg]http://files.abovetopsecret.com/images/member/19441735e291.jpg[/atsimg]

reply to post by StealthyKat


The FPSO is anchored by 10 seperate chains to the sea floor to keep it in one position. Pipelines carrying gas and some carrying oil come from the sub-sea manifold (which is on the sea floor connected to the sub terranean reservoir via the well casing) then travel up to the turret on the ship.

When the ship broke loose from its moorings, all of these steel pipes were ruptured and fell to the sea floor. They say that they have managed to close the valves on the sea floor so no leak has occurred but intially when they ruptured, all of the gas leaked out and up through the turret. If the gas cloud had ignited, it would have been another major disaster.

hope thats clear

PEACE,
RK

reply to post by StealthyKat


Yes that is the position.....
I cannot upload a photo of it cos I dont have that facility from my work computer....
if you google it you will see the photo, it is quite a big vessel.

PEACE,
RK

reply to post by Rigel Kent


Rigel,

The factor of safety/environmental load considerations on chains like these would accomodate for heavy weather. They are even designed to withstand the loss of one anchor chain, ie: 9 keeping the vessel moored if the tenth were to fail, especially if the vessel has to sit through any weather that may crop up.

If chain failure did occur (and was the cause), it had to occur for one of two reasons. Either the weather (wind and waves) were abnormal and overloaded the moorings, or the moorings failed at a normal load. That's why I say it could have been poor maintenance.
In any case these are just wild guesses on my part

Glad no one was seriously hurt, I'm sure you got to know the crew while you were out there.

reply to post by Rigel Kent

Yes....you explained it well...thankyou! I'm glad no one was hurt

reply to post by Rigel Kent


Thank God no one was killed. These things make my heart go pitter patter. The gas clous doesn't sound good though. Thanks S&F

reply to post by Bagel


Good points, You are correct in your suggestions of safety factors etc, but I shy away from blaming it on poor chain maintenance because the 25yr lifespan is factored into the design stage as is the 100 year storm. Chains are all pretty much underwater so we can forget maintenance issues, there isnt any maintenance performed on the chains themselves.

In this depth of water we would probably find each length of "chain" would consist of a piece of chain at the top say approx 30 metres, connected to approx 120 metre section of High Tensile Spiral wound steel wire rope, say 68mm diameter and then that connected to a bottom chain of approx 30m in length which would be connected to a steel driven pile (easiest I can describe it would be like a super giant steel tent peg).

I am still working through my industry contacts to find someone who was actually on it at the time of the incident.The e-mail in the OP was fwd to me by a friend and was not sent to me directly.

PEACE,
RK

I stumbled upon this from looking at another thread here, I was on there at the time, what are you wanting to know?