Last year, in a record lease sale, Royal Dutch Shell PLC paid $2.1 billion for exploration blocks in the Chukchi Sea, off the coast of Alaska.

• 在去年一次创纪录的租售中，荷兰皇家壳牌公司支付21亿美元获得了阿拉斯加以外楚科奇海的勘探区块。