1. Relief wells
The first relief well is ahead of schedule, having reached a depth of 9,000 ft on Saturday.
The second drilling rig, the Development Driller II should be in position by mid-week. Drilling of the second relief well should commence over the weekend.
2. Containment dome/cofferdam
The clogging of the first containment dome by methane hydrate crystals has been widely reported and its details will not be repeated here. The most recent strategy is referred to as “top hat,” and involves the placing of a smaller dome (4 x 4 x 5 ft, weighing less than 2 tons) above the primary leak. This dome will already be connected to the riser system when it is lowered into position, which is expected to occur mid-week. BP plans to use anti-hydrate solutions (presumably methanol) via the riser to prevent a repeat of the hydrate clogging problem.
This Rigzone article provides further details:
3. “Top kill/junk shot”
Another strategy involves deliberately clogging up the existing blow-out preventer (BOP) by injecting various ground-up solids into the bottom of the BOP. Last week BP removed the “yellow pod/brain” from the BOP with the intention of reconfiguring it and re-inserting it in order to obtain data on pressures (and thus determine the feasibility and safety of this strategy). The expectation is that if this strategy is to be attempted, the attempt will be made in a week or two (ie. before the end of May).
4. New BOP
Another option is to shear off the lower riser and stick a new BOP on top of the existing one. However, this is described as “a very, very complicated task [which] also brings risks…”.
This Upstream Online article provides further details:
5. Congressional hearings
Senior executives from BP Americas, Transocean and Halliburton will face intense questioning today when they appear before two Senate committees. Tomorrow they face a House Energy & Commerce subcommittee.
One topic that is certain to be scrutinized is the use of nitrogen-injected cement to seal the well. Cementing was completed 20 hours before the blow-out occurred.
7. Government oversight
Another topic which is receiving intense examination is that of government regulation (with a particular focus on the Minerals Management Service), the degree to which industry has been allowed to self-regulate, and the role of backup systems.
This article from WSJ provides an excellent summary.
as does this article from Mike Soraghan of Greenwire.