Oilfield firm Halliburton Co. on Tuesday posted its third consecutive quarterly profit and said customer spending in the United States could jump 20 percent next year, as stronger oil prices and drilling activity boost demand for services and equipment. Oil prices have rallied to multi-year highs with global crude futures climbing 4.5 percent in the quarter ended Sept. 30, helped by OPEC+’s decision to maintain its planned output increase rather than raising it on global supply concerns. Brent oil futures are trading around $84.4 a barrel, up about 63 percent so far this year, while benchmark U.S. crude is at roughly $82.5 a barrel, up 70 percent over the same period. “I see a multiyear upcycle unfolding. Structural global commodity tightness drives increased demand for our services, both internationally and in North America,” Halliburton Chief Executive Officer Jeff Miller said. Miller said the company is reallocating some equipment to drive …