Occidental Petroleum Corp. (Oxy) has promoted Executive Vice President Vicki Hollub to senior executive vice president and president of Oxy Oil & Gas. She is to become CEO when Stephen Chazen retires; his retirement date has not been announced. A mineral engineering graduate from the University of Alabama with nearly 35 years of industry experience, Hollub began her career in 1981 with Cities Service, a year before it was acquired by Oxy.

Frank Patterson is joining Chesapeake Energy Corp. as executive vice president of Exploration Land and Subsurface Technology with the retirement of John Kapchinske. Patterson, like CEO Doug Lawler, is a former Anadarko Petroleum Corp. executive. He worked for the Houston area operator from 2006 until this year, most recently as senior vice president of international exploration. Patterson previously was vice president of deepwater exploration for Kerr-McGee Corp., which was purchased by Anadarko in 2006. He holds a bachelor's degree from the University of Oklahoma.