Mr Stewart has been Chairman and CEO of One X since November 2023 and also serves as director of Patterson-UTI since September 2023. Mr. Stewart served as a member of Keane’s and, subsequently, NexTier’s board of directors from March 2011 to September 2023. He joined Keane (predecessor to NexTier) in March 2011 as Chairman and Chief Executive Officer and served as Executive Chairman from August 2018 to October 2019. Prior to joining Keane, from 2007 to 2009, he served as the President and Chief Executive Officer of a privately held international drilling company. From 2006 to 2007, Mr. Stewart served as Vice President of Integrated Drilling Services for Weatherford International plc, based in London and Dubai, where he created and managed a global business unit that included a 50-rig international land contract drilling group and a global project management team. Mr. Stewart began his career with Schlumberger Limited, where he held senior leadership positions across the globe over the span of 22 years.