Energy executive Harold Hamm says oil prices should double to $60 by the end of 2016—a contrary prediction for a market currently bracing for oil to fall to $20. He also believes that Saudi Arabia made a “monumental mistake” in continuing to pump oil at a fast pace. The move not only depressed world prices but likely contributed to the lifting of the U.S. government’s 40-year ban on oil exports, Mr. Hamm said. The supply glut has been a major factor behind the dwindling price for oil over the past 18 months. Benchmark U.S. oil futures briefly dipped below $30 Tuesday, their lowest level since 2003. On Wednesday, U.S. oil settled up four cents at $30.48 a barrel on the New York Mercantile Exchange. Mr. Hamm, chief executive of top U.S. shale-oil producer Continental Resources Inc., CLR -6.48 % believes that the current glut will ease substantially this year […]