National Oilwell Varco Inc. CFO Jeremy D. Thigpen is stepping down to take over as CEO of Transocean Ltd., which owns the largest global fleet of offshore rigs. Thigpen, an 18-year NOV veteran, has served as CFO since 2012. He previously was president of downhole pumping and solutions. Transocean is one of NOV's biggest customers. Chief Accounting Officer Scott K. Duff was named interim CFO, and a search is underway to identify a new financial chief. Duff, who joined NOV in 2004, holds a bachelor's degree in accounting from the University of Texas at San Antonio and is a certified public accountant.

U.S. onshore operator American Energy Partners LP (AELP) has hired Scott D. Sachs as senior geoscience executive adviser, James C. Johnson as senior marketing and midstream executive and Traci D. Cook as chief accounting officer. All three previously worked for AELP founder Aubrey McClendon when he was CEO of Chesapeake Energy Corp. Sachs, 54, had been vice president of geoscience from 2005 to 2014 and spent 18 years at Marathon Oil Co. Johnson, 57, was Chesapeake senior vice president of marketing for 18 years and, beginning in 2000, was president of Chesapeake Energy Marketing Inc. Cook, 50, was a Chesapeake executive for 19 years and since 2006 had been vice president and division controller of financial analysis and reporting.