ADN.  A subsidiary of Royal Dutch Shell received federal approval FridayCurtis Smith by Dave Harbour, Shell, Alaska OCS, Beaufort Sea, Chukchi for drilling exploratory wells in the Chukchi Sea off Alaska’s northwest coast but with conditions that raised concerns with the state’s congressional delegation.  …   Shell Alaska spokesman Curtis Smith (NGP Photo) said the company is evaluating conditions outlined in the approval, including the stipulation that potentially limits the drilling season.  "We are concerned this unwarranted restriction could severely impact our ability to deliver a complete Chukchi program," Smith said in written comments.