Oil prices at $60 a barrel would be “ideal” for OPEC as higher levels risk sparking a recovery in competing supplies from the U.S., according to Nigeria’s petroleum minister. The “urgency” felt by the Organization of Petroleum Exporting Countries and its partners to end the oil rout will ensure they adhere to their Dec. 10 agreement to cut supplies, Emmanuel Kachikwu said in a Bloomberg Television interview on Monday. The accord should push prices — at about $56 today — a bit higher, yet not enough to trigger a comeback in U.S. shale, according to the minister. “Sixty I think would be ideal,” he said. “Once you begin to trend past the mid-$60s, you’re going to have a surfeit of shale producers jump back into the market. Technology is improving with shale every day, and so the cost of production is […]