Former Maersk Oil CEO Gretchen Watkins, 48, is taking over as Royal Dutch Shell plc’s executive vice president (EVP) of unconventionals effective July 1. Watkins is joining Shell on May 1 and would be based in Houston. Watkins, a former executive with BP plc entities and Marathon Oil Corp., became Maersk Oil COO in 2014 and was named CEO in 2016. Total SA in 2017 agreed to buy the company, which was the exploration unit of A.P. Moller-Maersk. Watkins is succeeding EVP Greg Guidry, who has worked at Shell for 36 years. Shell Oil Co. President Bruce Culpepper, who also is the U.S. country chairman, is retiring on Dec. 31 following more than 37 years with the company. Following his departure, Watkins would assume the role of president and U.S. country chair, reporting to the CEO.