Onshore operator Energen Corp. has elected David Bolton as vice president of land for the exploration and production unit. Bolton succeeds Paul C. Rote, who retired. Bolton formerly was southern division land director for Chesapeake Energy Corp., where he coordinated new ventures and land activities in the Permian Basin, South Texas and Midcontinent, as well as the Haynesville and Barnett shales. Birmingham, AL-based Energen is one of the top drillers in the Permian.