Among much hoopla Thursday, the Presidential Oil Spill Commission released a letter from lawyer Fred Bartlit, Jr., saying that 3 of 4 tests that Halliburton conducted of the cement designed for BP's Macando well were unstable. They also published a report of tests performed by Chevron that all nine of their tests using Halliburton ingredients showed it as unstable. One of Halliburton's tests run prior to the actual cement job showed that formulation to be stable and work. The letter also stated that the communication about the instability of the slurries between Halliburton and BP was unclear, and that BP may not have even read the report until after the blowout had occurred.
The media and stock market immediately jumped to the conclusion that Halliburton was at fault, and shares of the company dropped about 8% in value when the news hit. The problem is, though, that this report issued by the commission doesn't matter. While interesting and demonstrative of the instability of nitrified cements, the main message here is that bad cement does not equal blowout. Bad cement jobs in the oil and gas industry are common, and there are several ways to remediate those bad jobs after the fact. It's very difficult to determine if a cement job is not effective, even with a bond log, especially in the early hours after a cement job has been pumped. Bond logs are often inconclusive and the longer cement has to hydrate and gain compressive strength, the higher the likelihood of a better log. As we all know from the Deepwater Horizon story, there were only about 16 hours from the time the cement job was pumped to the negative test, riser displacement, and the subsequent blowout.
The overriding issues here are casing design and risk management. Relying solely on the cement job to prevent the well from coming to see them was poor decision making. I continue to believe that their decision to run only the long string, rather than a liner/tieback combination, as well as the decisions to not wait on more centralizers or to not circulate bottoms up, was BP and Transocean's concern about getting pipe to bottom and getting cement in place, not money. This well had been scary difficult to drill, losing circulation, then kicking, that they just wanted to get off as quickly as possible. This rush to get the well finished lead to the disaster. Add that to displacing the riser with seawater with questionable well integrity was the final straw. After the blowout, the inhibited alarms and safety shutdowns on the Transocean rig proved deadly.
This disaster was certainly preventable and caused by poor design, poor decision making, and rushing to get the well completed. The tragic consequences should be a lesson to the entire industry, but I'm not holding my breath.
Bob Cavnar's new book, Disaster on the Horizon is now available.