Oil prices fell more than $2 a barrel Friday after two of the world’s biggest producers indicated they might increase output at next week’s OPEC meeting, while U.S. exports were threatened by potential Chinese tariffs on crude oil and refined products. Oil investors have been nervous ahead of the coming OPEC summit in Vienna. Saudi Arabia and Russia have already boosted production modestly, and have indicated they were prepared to increase output at that meeting. Brent crude oil LCOc1 fell $2.50, or 3.29 percent to settle at $73.44 a barrel. U.S. crude CLc1 settled $1.83 lower at $65.06 a barrel. In post-settlement trading, U.S. crude retreated further, falling 2.25, or 3.4 percent, to $64.64 […]