OpinionOilfield services giants still face hurdles despite bright outlookPositive future on healthy fourth-quarter revenues, but some systemic challenges remainPhoto finish: The big US service companies reporting quarterly earnings this week — Baker Hughes, SLB and Halliburton — finished 2022 in fine form and their chief executives were upbeat about their prospects for the coming year. But as the E&P race picks up speed, some potential hurdles remain in play.UPSTREAM/RYTIS DAUKANTASRussell McCulleyLondon