Offshore Oil Rig Disasters: Deepwater Horizon & Piper Alpha
by Yunki Jo | CEO
The plant industry is a demanding sector that involves working with heavy machinery and is inherently prone to accidents. However, it plays a crucial role in society, despite the risks associated with manual labor.
Despite the strict regulations and protocols in place for the manufacturing, installation, and operation of industrial plants, accidents continue to occur at an alarming rate, particularly in the plant industry. Even in countries like Korea, where safety measures are typically stringent, there have been numerous incidents that have resulted in tragic consequences. For instance, the 2003 SK Energy Ulsan Refinery fire, the 2011 SK Energy Incheon Refinery fire, the 2017 S-Oil Ulsan Refinery explosion, the 2017 Hyundai Oilbank Seosan Refinery suffocation accident, and the March 2020 Lotte Chemical Seosan explosion are just some examples of the catastrophic events that have taken place.
In countries where the plant industry began to develop much earlier than in Korea, much larger accidents have occurred. Despite the implementation of stricter safety and environmental specifications, conditions, and regulations after infamous accidents that have left their mark on history, similar accidents unfortunately continue to occur.
This article will present in detail the major accident cases that have impacted not only the plant industry but also the global environment, categorizing them into offshore and onshore plants.
Deepwater Horizon Oil Spill
On April 20, 2010, the Deepwater Horizon oil rig in the Gulf of Mexico (GOM), located off the coast of Louisiana, USA, experienced a catastrophic explosion resulting in the deaths of 11 workers and injuries to 17 others. The incident led to the worst oil spill in the history of the petroleum industry, with an estimated 4.9 million barrels of oil leaking into the ocean. The disaster was so severe that a movie was made about it in 2016 with the same name, Deepwater Horizon.
April 20, 2010, at 9:50 PM
The Deepwater Horizon drilling rig, leased by BP — one of the world’s largest oil companies — from Transocean, a global offshore drilling contractor, was situated in the Macondo oil field. This BP-owned offshore facility was located in the Gulf of Mexico, approximately 40 miles off the coast of Louisiana, within the exclusive economic zone of the United States. The first explosion occurred due to a sudden and violent release of oil and gas from the well being drilled by the rig.
Following the first explosion, an uncontrollable massive fire broke out, leading to a second explosion. The 126 crew members on board the Deepwater Horizon were ordered to evacuate immediately. For some, the situation was so dire that they had to jump into the sea, as it was challenging to board the lifeboats.
According to BP’s internal investigation into the cause of the explosion, methane gas leaked from the reservoir. This gas traveled up through the drill column of the rig and quickly spread, breaking through multiple layers of seals and barriers before the explosion occurred.
Survivors of the Deepwater Horizon disaster described the situation as “a sudden explosion that gave us barely five minutes to escape.” Following the initial explosion, the platform was engulfed in a massive blaze, intensifying the danger for those still on board.
Efforts to disconnect the connection between the rig and the well or shut down the well were unsuccessful, resulting in oil gushing from the well and fueling the fire, which showed no signs of abating. On April 22nd at 10:26 a.m., the Deepwater Horizon sank into the Gulf of Mexico, causing the well to spew massive amounts of oil into the ocean. This catastrophe marked the worst environmental disaster in the history of the United States.
To summarize, out of the 126 crew members on board the Deepwater Horizon, 115 were able to escape the explosion, but 17 were injured. Unfortunately, despite extensive search and rescue efforts, 11 crew members were unable to be rescued and were declared to have perished in the initial explosion due to their proximity to it.
Despite BP’s announcement on September 19, 2010, that the well was successfully sealed and that there would be no further oil leakage, oil continued to be discovered along the Louisiana coast up to 320 km away as of April 2012. This discovery indicates that the Deepwater Horizon disaster caused extensive and long-lasting damage to the environment.
- Oil spill amount: 4.9 million barrels (780,000 m3) — the largest and worst maritime oil spill in history
- Spill range: 1,000 km to 2,092 km (U.S. coastlines near the Gulf of Mexico) Habitats of 8,332 species of marine life from coral to whale sharks
- Number of dead marine animals collected: birds — 8,183, sea turtles — 1,144, marine mammals — 109 (as of November 2010)
- Actual number of dead marine animals: more than 50 times the above numbers (source: Journal Conservation Letters)
Piper Alpha — World’s Deadliest Oil Rig Disaster
The explosion at the Piper Alpha Oil Platform in Scotland 30 years ago was a tragic incident that claimed the lives of 167 people. The aftermath of this disaster forced the oil and gas industry to reexamine safety issues and implement new measures to prevent similar accidents from occurring in the future.
July 6, 1988, Wednesday, 10 PM.
226 crew members were on board the Piper Alpha oil production platform, located 120 miles northeast of Aberdeen, Scotland, when they heard a sudden explosion on the platform deck. The flames rapidly spread through the modules, and black smoke covered the upper part of the platform. Surviving crew members reported that multiple small explosions followed the initial blast, and “sharp noises continued to be heard in the ears after the explosion.”
After the explosion at 10 pm, the crew issued three “Mayday” distress calls within eight minutes, and eventually signaled their intention to abandon the platform due to the fire in the final distress signal. Despite the efforts of the emergency rescue team to reach the scene, the situation proved impossible to evacuate due to the intense flames and heavy smoke.
The oil field where the accident occurred consisted of multiple platforms, as seen in the picture. At 10:20 pm, an additional massive explosion occurred, which could be felt even on ships several hundred yards away. This explosion was caused by a ruptured high-pressure gas line between the Piper Alpha platform and the Tartan platform. The ruptured gas line caused a massive fire, fueled by a large amount of high-pressure gas, which continued to burn for a prolonged period, generating intense heat.
Thirty minutes later, at 10:50 pm, another significant explosion occurred due to a ruptured gas line that transported gas from the Frigg field to St. Fergus through MCP-01. Unfortunately, a rescue boat departing from an atmospheric vessel was destroyed by this explosion, resulting in the deaths of the six people who had just been rescued and two crew members.
At 11:20 pm, the structural integrity of the Piper Alpha platform was severely compromised, causing the topside (which includes the structures on top of the jacket) to collapse, followed by the western crane and drilling derrick. The platform then tilted towards the east, and shortly after, the pipe deck collapsed towards the west. The main accommodation block, which served as a refuge for at least 81 crew members, slid into the sea, leading to the death of all crew members inside. The entire platform collapsed, resulting in a catastrophic disaster.
The day after the incident, on July 7, 1988, a significant portion of the jacket and around three-quarters of the topside were destroyed, sinking to the seabed 140 meters below in a tangled mass. It took three weeks to fully extinguish the fire, and the remaining debris of Piper Alpha was submerged in the sea in March 1989.
The Piper Alpha incident resulted in the loss of 167 lives, including platform staff and rescuers, with only 61 of the 226 crew members on board survived. The accident was caused by:
Inadequate maintenance
- The official investigation determined that the initial explosion on Piper Alpha was caused by simultaneous maintenance work on a pump and its safety valve (PSV), which resulted in the release of hydrocarbons, including propane.
Lack of minimum standards for communication
- The Claymore and Tartan platforms, which were situated in the same oil field as Piper Alpha, reported that they had heard the Mayday call, but they initially assumed that it was a manageable situation.
- The decision of the Claymore and Tartan platforms to continue production despite the mayday call contributed to the severity of the oil fire.
Poor safety procedures
- Due to the absence of adequate safety response manuals (or lack of training on them), at least 84 crew members waited for instructions from management while taking shelter in the accommodation facilities after the initial explosion.
- After the initial explosion, the managers on board Piper Alpha were unable to effectively respond to the situation. In fact, many crew members who sought guidance from management were left without any clear direction or instruction.
- The communication system on the platform was severely damaged by the initial explosion, and there was no backup plan in place to issue evacuation orders to the crew members.
There have been numerous maritime accidents, but the two accidents described above are the most representative offshore plant incidents. For further insight, I recommend watching the 2017 film, “Deepwater Horizon.
In next week’s article, I will summarize accidents that have occurred in onshore plants and provide a detailed analysis of them. My heart goes out to all those who were affected by these accidents, including those who worked hard on the scene and suffered losses.
