Efforts to clean oil from the Louisiana coast slowed down Wednesday, as spill response teams instead prepared for the impact of heavy rain associated with a now dissipated storm system in the Gulf of Mexico.
The Unified Command for spill response implemented its severe weather action plan at 3 p.m. Tuesday, instructing all response efforts to “stand down,” Coast Guard Petty Officer Erik Swanson said. The plan was activated for the safety of people working in low-lying areas prone to flooding.
The storm for much of the day Wednesday had been referred as Tropical Depression 5 by the National Hurricane Center. Forecasters had predicted that it would turn into Tropical Storm Danielle, with 40 mph winds, sometime before making landfall near Chalmette. But by Wednesday afternoon the storm had dissipated and was considered mainly a threat for flash flooding.
Although the storm is a reduced threat, the oil spill response effort was still suspended Wednesday evening.
Swanson said crews had removed about 26,465 feet of boom from marshy areas Tuesday to guard against the possibility that the boom would get tangled in the delicate marsh during the storm. Boom in “high risk” areas, however, will remain in place and in some cases additional boom was added in the expectation that the storm would push oil to shore, Swanson said.
It is not known when oil spill clean up efforts will resume.
“Right now we are closely tracking the weather,” Swanson said. “But it’s hard to say how long it’s going to last.”
Offshore, the Development Driller III rig that is drilling a relief well remained idled Wednesday. The rig has been plugged with a stopper called a “storm packer” and filled with sea water for protection until the storm passes, Allen said. The rig was not disconnected from the well it is drilling.
Allen said the rig would return to drilling the relief well 96 hours after the storm passes.
The relief well is being drilled to perform a “bottom kill” of the once gushing Macondo well, by pumping it with mud and cement at about 18,000 feet beneath the water’s surface.
Allen said Wednesday that BP engineers and government scientists are still trying to ascertain how best to complete that mission. The team will conduct pressure tests on the Macondo well’s annulus, an outer shell, this week with the hope of determining whether or not there is oil in the annulus and, if there is, whether it is static or coming from the reservoir. The finding will inform crews on how to proceed with the relief well.
If the oil is trapped in the annulus, with cement separating it from the reservoir, there is a chance that pumping the area with mud and cement would raise the pressure inside the well and possibly cause oil to push its way up into the blowout preventer at the top of the well and perhaps into the environment. Allen called that possibility a “low-probability event.”
Last week, a maneuver called a static kill succeeded in pushing oil that had been in the well bore back into the reservoir with heavy drilling mud inserted into the top of the well. The mud was followed by cement to seal the well. It is possible that some of the cement made its way into the annulus, Allen said.
Also on Wednesday, Allen said that he has begun planning for his exit strategy. Allen, who has been National Incident Commander since May 1, said he may transition from the role in late September or early October after he is certain that the well is killed.
