The early U.S. shale oil boom hinged on discovery, acquisition and first mover advantages. Now the story is one of management, execution and strategy. Sanchez Energy (SN) is executing its Eagle Ford, South Texas-based strategy at a sophisticated level. The company grabbed leases on 106,000 acres in the Eagle Ford from Royal Dutch Shell (RDSA) last month for a net $553.5 million, after adjustments.