On 20th April 2010, an uncontrolled flow of water, oil mud, oil, gas and other materials rushed out of the drilling riser and drilling pipe on a dynamically positioned drilling vessel at approximately at 5000ft of water in the Northern Gulf of Mexico, the coast of Louisiana. Methane gas from the well under high pressure shot up in the drill column, expanded onto the platform, then ignited and exploded. This explosion caused the deaths of 11 workers, severe injuries to many others and the release of crude to sea. The leak continued for 87 days with spills of 4 million barrels and caused massive environmental damage. A series of incident investigations were carried out to determine cause of the incident. Analysis of the available evidence indicates that when given the opportunity to save time and money, tradeoffs were made for certain things such as production because it was perceived that there are no downsides associated with the uncertainties. The importance of asset integrity was neglected and it caused the downfall of Deepwater Horizon [1].
Every single incident provides valuable lessons learned for us to avoid similar situations from recurring. The Deepwater Horizon incident is an example of oil and gas landmark accidents that happened in the past decades with devastating consequences and showcased that asset integrity must be always maintained at the highest possible standard [1].
The root causes of the accidents leading to the large property damage for refineries, gas plants, petrochemical plants and offshore oil and gas production were attributed to [2]:
- Inadequate PHAs/QRAs/Risk Assessments
- Use of wrong or poorly designed equipment
- Inadequate indication of process conditions
- Inadequate management of change process
- Lack of strong mechanical integrity program
- Lack of enforcement of Lockout/Tagout procedures
- Warnings from near misses, other accidents went unheeded.
All the above causes are related to the elements of process safety management, mechanical integrity, and change management. Some of the failures have also been associated with improper design of the equipment for particular process conditions such as wrong material selection [2].
References:
[1] Ramasamy, Jeyanthi, Yusof, and S. ’ Ri M, “Critical Safety Elements in Subsea Asset Integrity Framework,” 2015.
[2] J. P. Tronskar, “Asset integrity management involving integrated RBI and RCM,” 2003. [Online]. Available: https://www.researchgate.net/publication/293738065