BP Chief Executive Bob Dudley, who coined the phrase “lower for longer” about oil prices,… A rally that pushed international crude-oil prices above $50 a barrel Thursday is a welcome sign for many energy companies but not enough to kick-start an industry in the midst of a two-year slump, executives said. “We’re in a little bit of an upswing at the moment and everybody’s got a smile on their face because we might be at $50 a barrel,” said Tony Durrant, chief executive of Premier Oil PMO 2.61 % PLC, a British oil company with operations from the North Sea to the Falkland Islands. But, Mr. Durrant said in an interview Thursday, “every day of every week I’m talking to our joint venture partners around the world and I hear people still canceling projects.” Oil prices remain far below the $100-a-barrel area that energy companies had become accustomed to […]