Maybe Thad Allen just can’t let go. A few days after telling reporters that the final stages of the relief well was likely to go forward this week, it seems we might all have to wait a while longer. Further pressure tests on the well now indicate that some amount of concrete leaked into the annulus, or outer casing, during the earlier static kill. Concrete either leaked directly through the casing pipe, or entered the annulus up from the reservoir. Worse, some 1,000 barrels of oil may be trapped in the annulus, and the wrong drill at the wrong time could lead to a new leak—albeit admittedly one that might be equivalent to the amount of oil the blown BP well was gushing every 20 minutes or so before it was capped last month. “Nobody wants [the relief well] any more than I do,” Allen told reporters today. But the process “will not start until we figure out how to manage the risk of pressure in the annulus.”
The problem isn’t new—we’ve known for a while that adding additional mud or concrete via a relief well could increase the pressure in the annulus, and that could impact parts of the capping stack on the top of well, which has a limited ability to resist added pressure. But now it turns out that additional measures could be needed to finally finish the job—including removing the capping stack altogether. BP could then also replace the well’s original blowout preventer—a piece of equipment still sitting on top of the well—with a new one better able to withstand additional pressure. Or BP could try to jury-rig a pressure relief system on the existing capping stack.
Either way, it’s still going to take another 96 hours for the relief well to be finished, once BP gets the go ahead. (Expect Energy Secretary Steven Chu to have a strong say in how things go.) But now once the relief well hits its target, making contact with the original well, BP will wait another 7 days as Chu and the science team figures out how to manage this pressure problem. Altogether that could mean the end of the well could drag on into September—more than four months after the original accident.
But there’s a good reason for all this. “We’re using an overabundance of caution,” Allen said. As well they should. Now let’s see whether we can apply that same overabundance of caution to new deepwater drilling.
Somehow I doubt it.