[Update: latest post with video feed embedded is here].
BP finally abandons the attempted “top kill”, after trying for more than 72 hours
11.30pm BST (5.30pm EDT, 6.30pm CDT)
As the pessimists have been predicting for some time, BP has been forced to abandon its “top kill” attempt to force mud down its leaking well to stop the oil escaping.
Now on to the next plan. Not so much Plan B as Plan F, already. The idea now will be to cut off the pipes at the top of the blow-out prevented, exposing the Lower Marine Riser Package, and allowing a container to be connected up to it that will catch the oil and allow it to rise up a pipe to the surface. Like all of these efforts, this has not yet been done before in 5,000 feet of water. It also carries risks: not least that by cutting away the buckled pipe at the top of the BOP, you will make is easier for oil to escape.
The new plan will take about four days to execute, BP says. And if that fails, then it will be on to Plan G: fastening a new blow-out preventer on to the top of the existing one on the well, which failed in the accident on April 20.
BP’s statement explains:
Despite successfully pumping a total of over 30,000 barrels of heavy mud, in three attempts at rates of up to 80 barrels a minute, and deploying a wide range of different bridging materials, the operation did not overcome the flow from the well.
The Government, together with BP, have therefore decided to move to the next step in the subsea operations, the deployment of the Lower Marine Riser Package (LMRP) Cap Containment System.
The operational plan first involves cutting and then removing the damaged riser from the top of the failed Blow-Out Preventer (BOP) to leave a cleanly-cut pipe at the top of the BOP’s LMRP. The cap is designed to be connected to a riser from the Discoverer Enterprise drillship and placed over the LMRP with the intention of capturing most of the oil and gas flowing from the well. The LMRP cap is already on site and it is currently anticipated that it will be connected in about four days.
This operation has not been previously carried out in 5,000 feet of water and the successful deployment of the containment system cannot be assured.
Drilling of the first relief well continues and is currently at 12,090 feet. Drilling of the second relief well is temporarily suspended and is expected to recommence shortly from 8,576 feet
More on relief well suspension; LMRP; black plumes
2.09pm BST (10.09am EDT, 9.09am CDT)
The BP video feed is showing the riser outflow, rather than the BOP that was on view much of yesterday. It’s still showing a billowing plume of what appears to be oil. Heading Out on The Oil Drum believes the riser would not show a reduced flow until the injections of mud and junk are almost completed, because its smaller cracks would take longer to be blocked by the junk.
Here’s a re-cap of the procedures being carried out or considered:
1. The top kill and junk shots - there is a good simple description at the top of Friday’s The Oil Drum thread. It also explains why the procedure would stop and re-start several times.
2. LMRP/new containment vessel
UpstreamOnline explains what the next tactic will be if the mud-and-junk approach fails:
If the top kill does not work, the UK supermajor plans to cut off the riser from the lower marine riser package (LMRP) and attach another to collect the flow.
The device would be coupled to a flex joint above the LMRP with a sealing grommet to keep water out of the flow and control gas hydrate formation.
The replacement LMRP cap is already on the sea floor, and BP’s chief operating officer Doug Suttles said late Friday that this could be deployed in about four days.
3. Second BOP
If neither the top kill nor the new containment cap works, the company is readying a second blowout preventer to place on top of the existing, broken BOP. This is why it has suspended work on the second relief well: it is readying the BOP from that well rig for this option. From Reuters:
BP spokesman David Nicholas said the company stopped that drilling so that rig’s blowout preventer could be retrieved from the seabed to be ready to place on top of the failed one if the company decides to do that. Each drilling rig uses a blowout preventer at the wellhead.
Drilling of second relief well suspended
12.20am BST (7.20pm EDT; 6.20pm CDT)
Suttles confirmed drilling of the second relief well had been suspended [update on the update: this was to make that rig's blowout preventer available to put on top of the failed BOP, if necessary]. Audio of the latest press conference is now available.
Another 24 – 48 hours, says Suttles
11.55pm BST (6.55pm EDT; 5.55pm CDT)
From Reuters: HOUSTON, May 28 (Reuters) – BP Plc.’s “top kill” operation to choke off a blown-out well with heavy mud will continue for another 24 to 48 hours, Chief Operating Officer Doug Suttles told a media briefing on Friday.
Reports of temporary stall to pumping
11.30pm BST (6.30pm EDT; 5.30pm CDT)
The New York Times is reporting the procedure stalled again early Friday, quoting an anonymous source:
The company suspended pumping operations at 2:30 a.m. Friday after two junk shot attempts, said the technician, who spoke on the condition of anonymity because he was not authorized to speak publicly about the efforts.
The newspaper says pumping resumed after almost 12 hours.
The Oil Drum’s latest discussion thread is here. They are also running an IRC channel, for old-school types; instructions near the top of the thread.
More FT coverage here.