Macondo Changed BOPs But There Is a Limit

Abstract

There is a limit to disruptive innovation in oilfield technology. Blowout preventers (BOP) show how hard it can be. A decade ago on 20 April 2020, the Macondo disaster made a powerful case for change when this last line of defense failed to stop a blowout that caused explosions and a fire that killed 11, destroyed the Deepwater Horizon drilling rig, and set off one of the largest oil spills ever in the Gulf of Mexico. Scathing reports from investigations and staggering payouts from lawsuits against BP and other companies highlighted the shortcomings of machines that failed to serve as the last line of defense when natural gas surged onto the drilling floor, setting off a series of explosions. The investigations highlighted a long string of errors that led to the avoidable crisis. There was a failure to verify the cementing, missed signs of gas building up in the well, and a delayed decision to activate the BOP until the explosions already may have severed the hydraulic lines to the wellhead. But the simple explanation for it all: The shear rams failed to sever the pipe and seal the well. In the aftermath, well-control standards and regulations were rewritten and expanded. The changes required that old recommendations became requirements, and new ones were added, including a strong push toward real-time monitoring. The reports did not propose fundamentally redesigning BOPs. But for engineers with an inventive streak, this looked like a call to rethink the driving force behind these hydraulic devices where the fundamentals have changed little since the first patent was issued nearly 100 years ago. The arguments for rethinking BOPs included a 2003 study by West Engineering Services that found shear rams failed 7.5% of the time based on an estimate of the typical force required to cut pipe at the time. The force needed rises as casing gets tougher, water depths deeper, and well pressures higher, according to the study funded by what is now the US Bureau of Safety and Environmental Enforcement (BSEE). A Det Norske Veritas study for Transocean completed before the Macondo blowout found 11 situations where a BOP was activated in an emergency among the 15,000 wells drilled from 1980 to 2006. The BOPs only worked six times during that period, according to a story in The New York Times published in June 2010 - while the industry was scrambling to find a way to stop the Macondo leak. Different Perspectives The innovators range from startups to major offshore drillers. A Norwegian engineer started a company to sell a design for all-electric BOP stacks and an offshore drilling contractor developed an electric motor to retrofit into a BOP body. Engineers with military and space experience created cutting devices powered by gas generators using solid chemical propellants that send out high-pressure streams of gas when ignited by an electrical signal, similar to the deployment of an airbag or the thrusters on the Space Shuttle (this technology has been around for a long time).