The loss of life at the Macondo site on April 20, 2010, and the subsequent pollution of the Gulf of Mexico through the summer of 2010 were the result of poor risk management, last‐minute changes to plans, failure to observe and respond to critical indicators, inadequate well control response, and insufficient emergency bridge response training by companies and individuals responsible for drilling at the Macondo well and for the operation of the Deepwater Horizon.Listed among the causes was failure to detect the gas kick in the first place, risky casing design, multiple simultaneous operations, management changes, poor communication, failure to enforce safety rules and regulations, and complete failure of the blowout preventer systems once the well had blown out. Notably, the report determined that the same on-duty drilling crew that failed to recognize this kick that turned into the blowout had failed to recognize a previous kick on this very same well. I found the JIT’s report on the blowout’s flow path to be the most interesting and revealing information to date about the condition of the well after it had been killed and was being permanently plugged during the Fall of 2010. They studied 3 possible flow path scenarios:
- Backside blowout, where cement on the outside of the casing failed and the well flowed up the outside of the production casing through the seal assembly, up the riser to the surface.
- Backside blowout up to the 7″ by 9 7/8″ crossover joint and up the annulus or outside of the casing, and up through the casing.
- Blowout up the production casing due to failed cement and float equipment in the production string itself.
- Schlumberger (a downhole well measurement company) ran a scanning tool to measure the characteristics of the fluid outside of the 9 7/8 casing, determining that there was no free gas present, eliminating scenario 1, the backside blowout. They then actually perforated the casing to check for presence of hydrocarbons and pressures indicated again that there was no gas present and no flow from the well outside the casing. Subsequent testing showed no erosion of the seal assembly in the casing head at the sea floor, indicating that there had been no flow through it. Backside blowout eliminated.
- To test scenario 2, the JIT relied on the successful positive pressure test performed on the casing string they pressure tested the casing and components, including the crossover joint, indicating that it was holding. Scenario 2 eliminated.
- Scenario 3, which they couldn’t actually test, was determined to be the cause of the blowout. This scenario would have involved contamination of the cement in the shoe track (the bottom section of the production casing) and failure of the 2 float valves at the top of the shoe track. Although we can’t test for it, it’s entirely possible, especially after testimony during the investigation that confirmed that the float equipment malfunctioned, requiring 9 attempts to activate it during the casing cementing operations on April 19th/April 20th. Multiple failures of these components is relatively rare, and since they are always cemented in, it’s impossible to determine actual failure cause. For example, the entire shoe track could have parted from the main casing string allowing flow up the inside of the production string.
Although the Panel found no evidence that MMS regulations in effect on April 20, 2010 were a cause of the blowout, the Panel concluded that stronger and more comprehensive federal regulations might have reduced the likelihood of the Macondo blowout. In particular, the Panel found that MMS regulations in place at the time of the blowout could be enhanced in a number of areas, including: cementing procedures and testing; BOP configuration and testing; well integrity testing; and other drilling operations. In addition, the Panel found that there were a number of ways in which the MMS drilling inspections program could be improved.The industry and BOEMRE continue to nibble around the edges of this important issue, even as the resistance to substantive improvements remains strong and growing. I fear it will take yet another tragedy to force real reform to how we drill the offshore. Maybe next time it will even drive our politicians into developing a real energy policy, but I’m not holding my breath. Reposted from The Huffington Post, where you can read the original.
|Bob Cavnar is the author of Disaster on the Horizon.|
Bob Cavnar is a 30-year veteran of the oil and gas industry with deep experience in operations, start-ups, turn-arounds, and management of both public and private companies. He was most recently President and Chief Executive Officer of Milagro Exploration, a large, privately held oil and gas exploration firm based in Houston, Texas with operations along the Texas, Louisiana, Mississippi Gulf Coasts, and offshore in the Gulf of Mexico. Cavnar holds a Master of Business Administration degree from Southern Methodist University and completed the Program for Management Development at the Harvard Business School. He blogs at dailyhurricane.com.