Sara N. Ortwein has become president of ExxonMobil Corp.'s onshore subsidiary XTO Energy Inc.and will be based in Fort Worth, TX. Ortwein, who previously served as president of ExxonMobil Upstream Research Co., takes over from Randy Cleveland. Ortwein joined predecessor Exxon Co. U.S.A. in 1980 as a drilling engineer. In 1997, she was named reservoir evaluation and planning manager for Exxon Ventures CIS (Commonwealth of Independent States), focusing on new venture pursuit and capture in Russia, Azerbaijan and Kazakhstan. Ortwein in 2001 became a corporate upstream adviser to senior management and three years later was named production manager for U.S.-operated production. Ortwein was named vice president of engineering in 2006 for ExxonMobil Development Co. The Houston native earned a bachelor of science in civil engineering at the University of Texas at Austin.