The company was granted permission to starting digging with its drill ship, but only into the layer of the ocean bottom that's above oil reservoirs. Shell can dig mud-line cellars, which will eventually hold and protect a well's blowout preventer, down 40 feet (12 meters) into the seabed. The company is also authorized to drill narrow pilot holes down another 1,500 feet (457 meters).
“These activities are essential safety steps that will allow for the installation and protection of the blowout preventer,” Salazar said in a teleconference with reporters.