In 2010, the industry came together to bring BP’s Macondo well in the US Gulf of Mexico under control.
The blowout, explosion and fire on the semi-submersible Deepwater Horizon was not the offshore industry’s first deadly blowout.
But it has had a profound and lasting effect on how drillers, operators and governments plan for such events.
All three of the basic pillars of a source control response were used for Macondo – capping, which contains as part of its response the capping stack, also known as the capping stack, containment, in this case a top hat that served as an early production system, and a relief well.
“The industry capped Macondo using an assemblage of parts that were put together in a rapid way to form what is now known as a capping stack,” says Brett Morry, global technical director for Trendsetter Engineering, which supplied technical expertise, design engineering and manufacturing support during the disaster response.
“Capping stacks weren’t new. They were just new to the offshore industry.”
An estimated 5 million barrels of oil flowed from Macondo in the months it took to shut in the well.
In the immediate aftermath, the US government imposed a drilling moratorium until new requirements could be established, and public outrage abounded.
“We’d had well control incidents offshore, but never with the level of public scrutiny as seen on Macondo,” Morry says. “Macondo was the upstream industry’s Exxon Valdez.”
During the1989 oil spill in Alaska, the Exxon Valdez oil tanker struck Prince William Sound’s Bligh Reef and spilled 260,000 barrels of crude oil over the next few days.
That incident, which led to the Oil Pollution Act of 1990 and new regulations in Alaska, involved a finite amount of oil. The Macondo spill, which occurred at the well and involved a much greater volume of hydrocarbons, led to new safety and planning requirements to ensure the industry could handle another such incident.
The resumption of drilling in the Gulf of Mexico hinged on the availability of an offshore capping stack, a technology that had been used onshore since the 1940s.
Drilling operations already rely on a primary method of source control with the blowout preventer. The new requirements called for access to a secondary method.
“The industry can use the capping stack to quickly respond to the need for source control. Our philosophy has always been for the industry to have the necessary equipment to stop losses,” says Bryan Domangue, acting supervisor for regional field operations at Bureau of Safety & Environmental Enforcement (BSEE).
The capping stack, he says, is “a rudimentary BOP. It’s designed to be light weight and easy to install.”
“There were so many things BP attempted throughout the process” of shutting in Macondo, he says.
“We learned over time what we thought were the best methods. That incident helped the BSEE determine its preferred secondary source control methodology.
“The BSEE has an overall concept of what containment should look like. MWCC and HWCG are aware of what those things are,” he says, referring to the Marine Well Containment Company and Helix Well Containment Group, the two industry consortia established after Macondo to provide containment response in the Gulf of Mexico.
One of the first steps in containment is clearing debris around the well to permit vertical access.
“Operators have to demonstrate that they have the equipment and capability to remove that debris,” Domangue says.
Additionally, they must prove they can deploy subsea dispersants so vessels can work at the site, along with temporary subsea collection capability such as a top hat while the capping stack is being readied for installation.
Finally, they must show they can install the capping stack. After the operator and the BSEE complete a reservoir analysis and conclude the well can safely be shut in, the well is shut in.
If it cannot be fully shut in, the operator must be prepared to do a cap-and-flow exercise. The subsea capping stack is installed and the operator supplies a means of sending the flow to a production facility at the surface.
Joint efforts
One of the BSEE’s considerations is the different locations where the capping stack can be placed.
“The nature of the incident will dictate where the capping stack can be installed,” Domangue says. It may be necessary to remove the old BOP, or it may be possible to install the capping stack atop it.
With the new capping stack requirement in place, ExxonMobil turned to Trendsetter Engineering to design and manufacture the equipment. Around the same time, the operator joined forces with Chevron, ConocoPhillips, and Shell to found the MWCC.
Because no one could drill until it was complete, the offshore drilling industry was effectively shut down. The industry quickly came together to supply the components needed to assemble an interim capping stack “that would meet the needs of the industry and give the US government the confidence that the industry had sufficient hardware in place”, Morry says.
“For me, ignorance was bliss. I didn’t know how big the task was,” he says.
Trendsetter leveraged the personal relationships of then-president Mario Lugo to source the required components.
“We were given a task. We were given an impossible timeline. We relied on Mario picking up the phone to ask people what they had in inventory. We designed the first capping stack around what was available at the time.”
Trendsetter, which had 20 employees at the time but has since grown to 150, delivered the interim capping stack system in less than two months. Morry calls it a “packaging exercise in the extreme to get something assembled together as quickly as possible”.
Then-Interior Secretary Ken Salazar inspected the capping stack in February 2011 at the Trendsetter facility, and the drilling moratorium was subsequently lifted for members of the newly formed MWCC.
“That was fine if you were a supermajor. But a lot of independents didn’t have access because they were not a member of the MWCC,” Morry recalls.
Led by Noble Energy and Cobalt International Energy, about two dozen independents formed the HWCG and contracted with Trendsetter for a stack of their own.
“The moratorium was still on those without access to a capping stack, so they wanted it as soon as possible,” Morry says.
“We’d already built the first capping stack. We then proceeded to build the second. We’d already identified a design and showed we could build one.
“We basically repeated what we did for the first stack with minor tweaks to meet the operators’ needs.”
Trendsetter delivered the HWCG stack in six weeks, and the “Gulf of Mexico was back on track”, Morry says.
“Both the HWCG and the MWCC installed capping stacks subsea during an exercise. From a satisfaction standpoint, we deemed those tests to be successful,” Domangue says.
The tests called for the groups to ready a capping stack onshore, install it on a vessel, take it to deep water, install it on a test wellhead, and test it subsea.
Domangue says the BSEE continues to oversee periodic tests to ensure the equipment functions as required.
He does not expect any new regulations any time soon regarding offshore source control, as the latest update to requirements for drilling in US waters was put in place in 2016.
“That regulation was added after many years of working with the industry to come up with the best possible solution for containing a subsea loss of well control,” Domangue says.
“As the industry moves to higher pressure, higher temperature environments, we’re constantly evaluating and working with the containment organisations,” he says.
“We have to constantly evolve. If we don’t, we just stagnate and accept the status quo, and we know we need to be better than that.”
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