On 20 April 2010, the Macondo blowout in the U.S. Gulf of Mexico killed 11 men, burned and sank the Deepwater Horizon drilling rig, and devastated the Gulf. Investigative authorities queried mechanical systems, operating decisions, corporate cultures, safety procedures, and testimony by survivors, academics, experts, and executives. Meanwhile, industry personnel need succinct, non-litigious, technical answers to fundamental questions about the cause of the blowout for application to future projects. Such answers define the specific mechanics, actions, and decisions on the rig that collectively opened a pathway into a cased-and-cemented deep-water wellbore and allowed hydrocarbons to flow unobserved from a high-pressure reservoir to eventually erupt over the derrick and continue even after the blowout preventers were closed.
To unravel the cause of the blowout, data during the well's final hours are assessed and defined using petroleum-engineering fundamentals, including wellbore mechanics, hydrodynamics, inflow performance, fluid properties, well-control principles, etc. The chain of events thus revealed includes forming an annulus-to-wellbore leak, exacerbating the leak, testing and declaring the well secure, causing the well to flow, and allowing the well to flow until too late, even for the blowout preventers. The technical assessment leads to conclusions that define those factors that contributed to the blowout, as well as to those that caused the blowout.
From the presentation, SPE members and a wider audience from across the industry and beyond will see by example the necessity and importance of applying petroleum-engineering and process-management fundamentals to day-to-day drilling work, in real time, both in the office and on the rig. From the Macondo assessment, a process-interruption protocol is defined, which can be applied to wells around the world, whether deep or shallow, onshore or offshore.