Sanctions to shut down activities of Russian oil firms: U.S. official

WASHINGTON (Reuters) - U.S. sanctions against five Russian oil firms are designed to shut down deepwater, Arctic offshore, or shale oil exploration projects, a senior U.S. official said on Friday after Washington imposed more sanctions against Russia for its intervention in Ukraine. "It is designed to effectively shut down this type of oil exploration and production activity by depriving these Russian companies of the goods, technology and services that they need to do this work," the official said. (Reporting by Lesley Wroughton; Editing by Doina Chiacu)