Defining the Problem

The crew members, engineering supervisors, and contractor specialists on board the Deepwater Horizon must have felt both pleased and proud on the morning of April 20, 2010. They had successfully completed drilling what BP (formerly British Petroleum) termed the Macondo well to a near-record depth. The “wellhead” (the partially embedded top structure of the well, where the valves, controls, and emergency disconnects were located) was on the ocean floor, 5,000′ beneath the surface of the sea, and the “pay zone” (the large reservoir of oil and natural gas that had been reached) was 20,800′ further down, past numerous layers of hard sedimentary but easily fragmented rock. Everyone involved, both those on board the drilling rig and those on shore in company offices, recognized that this was a remarkable achievement.