Cap may erase sense of hopelessness in oil spill
Sunday, July 18, 2010
So is it over?
Not technically, not politically, not environmentally. BP's Macondo well remains dangerous, a threat to gush anew, and very much alive until it is plugged with cement in a bottom-kill that's still weeks away at best. Criminal and civil investigations are going full bore. Exploratory drill rigs remain locked out of the deep water as the oil industry tries to prove that it knows what it's doing. Lawsuits are flying. And the ecological impact is still playing out as uncounted millions of gallons of oil pollute the Gulf of Mexico.
But something may have come to an end in the past few days: the sense that nothing would ever go right with this demon well.
Macondo for the moment is shut in. It's not dead, but neither has it spewed any oil into the gulf since Thursday. After a lengthy meeting between government scientists and BP engineers Saturday afternoon, retired Coast Guard Adm. Thad Allen gave BP permission to keep the well sealed for another 24 hours, extending an "integrity test" that strangled the well for the first time and kicked the crisis into its endgame.
That could mean that the well will be reopened Sunday afternoon. Allen's directive appeared to have been crafted to keep all options on the table, but the default position remains that the shut-in procedure will come to an end at some point.
"When this test is eventually stopped, we will immediately return to containment" using the new, tight-fitting cap on the well and surface ships that can capture or flare oil and gas, Allen said.
The shutting-in of the well was never the primary purpose of the "3 ram capping stack" lowered onto the top of the well Monday night. The 75-ton cap, which replaced the loose-fitting "top hat," was conceived as a mechanism to permit the capturing of more oil after it became clear that early flow rate estimates were far too low. Along the way, engineers raised the possibility that they could use the valves on the new cap to turn off the well as one might an ordinary faucet.
Administration officials, including President Obama, have emphasized that a re-opening of the well would not mean a return to the same ugly scene of a billowing gusher. But the optics will be unpleasant in the short run. Re-opening the well would mean that the oily plume, omnipresent for months on cable TV and Internet feeds from the deep gulf, would return at least temporarily as engineers open the choke valve and let oil and gas vent into the gulf.
"If we make the decision to open up the well, there will be a period when oil will go back into the gulf," BP senior vice president Kent Wells said Saturday morning.
What has been called the worst environmental crisis in U.S. history has also been a technological crisis, carrying echoes of Three Mile Island, which rattled the nuclear power industry, and Apollo 13, which challenged engineers to fix a problem -- moon-bound astronauts in a broken spaceship -- no one had ever faced. For 87 days, from April 20, when the Macondo well blew out and ignited a fireball on the doomed rig Deepwater Horizon, killing 11 workers, until Thursday afternoon, the well defied all plans to throttle it.
The new cap gave engineers more leverage. The well could yet spring a surprise. Robotic vehicles are staring at the mud around the blowout preventer and in all directions, looking for new leaks. They're using sonar, acoustic instruments, seismic detectors. They're taking the temperature of the casing; they're sampling bubbles coming out of a valve. It's a situation where everyone is hopeful but still checking all the closets and under the beds.
Officials remain concerned about "low probability, high consequence" hazards. But Wells said that engineers and scientists are increasingly confident that the well isn't leaking into the geological formations.
"There's no evidence that we don't have integrity," Wells said.
The pressure in the well was measured Saturday morning at 6,745 pounds per square inch, rising only a couple of pounds per hour and nearing equilibrium. That pressure level is ambiguous. Scientists had hoped to see pressures above 7,500 psi, or even 8,000 or 9,000, officials have said, because such high pressures, holding steady, would be clear evidence that the well casing is sound. If lower than about 6,000 psi, there could be little doubt that the casing has failed.
The middle range has created two competing scenarios. One is that that there are leaks that have kept the well from pressurizing further. The other is that the reservoir is running out of gas -- and oil -- after gushing for so long. The protracted nature of the disaster could have partially depleted Macondo, which is the best-case scenario for the pressure test if not the prettiest picture in the broader sense.
Wells said BP favors this second scenario because of the way the pressures rose steadily, fitting a model that's consistent with a well that isn't damaged.
No one has popped champagne or expressed any triumphalism. BP engineers and their associates from other oil companies helping out in the BP war room are unlikely to boast of success given the previous setbacks and the initial, fatal disaster itself, and the government will not be presenting the oil company any bouquets.
The ultimate end will come, officials hope, when a relief well plugs Macondo with mud and then cement. The first of two relief wells is getting close and should intercept the well around the end of July, with the bottom-kill taking anywhere from a few days to a few weeks, Wells said.