One technology that could have been useful in the Deepwater case is an acoustic valve to shut off the well by remote control in an emergency. Such devices are required by Brazil and Norway, but not by the United States, where the oil industry successfully resisted a proposal years ago to require its use, according to Oystein Noreng, who heads the petroleum studies unit at the Norwegian School of Management.
“In Norway, for more than 40 years, we have had a fairly harmonious coexistence between a large offshore oil industry and some of the world’s largest fishing industries,” Mr. Noreng said in an e-mail message. “Nobody can say that a disaster like the one in the U.S. Gulf of Mexico could not happen in Norway, but we have invested in the additional line of defense, thanks to political wisdom.”