For that reason, the one thing we know with certainty is that on the evening of April 20, there was a sudden, catastrophic failure of the cement, the casing, or both. Therein lies the root cause of this occurrence; without a disastrous failure of one of those elements, the explosion could not have occurred. It is also clear that the drill crew had very little (if any) time to react. The explosions were almost instantaneous.
What caused that catastrophic, sudden and violent failure? Was the well properly designed? Was the well properly cemented? Were there problems with the well casing? Were all appropriate tests run on the cement and casings? These are some of the critical questions that need to be answered in the coming weeks and months.
Over the past several days, some have suggested that the blowout preventers (or BOPs) used on this project were the cause of the accident. That simply makes no sense. A BOP is a large piece of equipment positioned on top of a wellhead to provide pressure control. As explained in more detail in the attachment to my testimony, BOPs are designed to quickly shut off the flow of oil or natural gas by squeezing, crushing or shearing the pipe in the event of a "kick" or "blowout" - a sudden, unexpected release of pressure from within the well that can occur during drilling.
The attention now being given to the BOPs in this case is somewhat ironic because at the time of the explosion, the drilling process was complete. The well had been sealed with casing and cement, and within a few days, the BOPs would have been removed. At this point, the well barriers - the cementing and the casing - were responsible for controlling any pressure from the reservoir.
To be sure, BOPs are an important aspect of well control. During drilling, BOPs provide a secondary means of controlling pressure if the primary mechanisms (e.g., drilling mud) prove inadequate. BOPs are robust, sophisticated pieces of equipment that can be activated by various direct and remote methods. Since the BOPs were still in place in this circumstance, they may have been activated during this event and may have restricted the flow to some extent. At this point, we cannot be certain. But we have no reason to believe that they were not operational - they were jointly tested by BP and Transocean personnel as specified on April 10 and 17 and found to be functional. We also do not know whether the BOPs were damaged by the surge that emanated from the well beneath or whether the surge may have blown debris (e.g., cement, casing) into the BOPs, thereby preventing them from squeezing, crushing or shearing the pipe.
For these reasons, I believe it is inappropriate to focus any causation discussions exclusively on the BOPs. Certainly, we need to understand what happened to the BOPs and whether changes should be made to improve the effectiveness of these devices in the unusual circumstances of an accident like the one on April 20. But the BOPs were clearly not the root cause of the explosion. Our most important task is to understand why a cased and cemented wellbore suddenly and catastrophically failed. As a starting point, our investigative team has looked at numerous possible causes, contributing factors, or trigger events, in an effort to ensure that nothing is overlooked in this investigation.
As I explained earlier, the well construction process is a collaborative effort. For the same reason, the process of understanding what led to the April 20 explosion and how to prevent such an accident in the future must also be collaborative. Ours is an industry that must put safety first. And I can assure you that Transocean has never - and will never - compromise on safety. In 2009, Transocean recorded its best ever Total Recordable Incident Rate (TRIR). And the federal agency charged with enforcing safety on deepwater oil rigs, MMS, which - as you know - is a unit of the U.S. Department of the Interior, awarded one of its top prizes for safety to Transocean in 2009. The MMS SAFE Award recognizes "exemplary performance by Outer Continental Shelf (OCS) oil and gas operators and contractors." In the words of MMS, this award "highlights to the public that companies can conduct offshore oil and gas activities safely and in a pollution-free manner, even though such activities are complex and carry a significant element of risk." In awarding this prize to Transocean, MMS credited the Company's "outstanding drilling operations" and a "perfect performance period."
Despite a strong safety record, Transocean has never been complacent about safety. We believe that any incident is one too many. Last year, our Company experienced an employee accident record that I found unacceptable. As a result, I recommended to our Board of Directors that they withhold bonuses for all executives in order to make clear that achieving stronger safety performance was a basic expectation - and fundamental to our success. That recommendation was accepted, and our Company paid no executive bonuses last year, in order to send a loud message that we evaluate our success in large part based on the safety of our operations.
Until we fully understand what happened on April 20, we cannot determine with certainty how best to prevent such tragedies in the future. But I am committed - for the sake of the men who lost their lives on April 20, for the sake of their loved ones, for the sake of all the hard-working people who work on Transocean rigs around the world, and for the sake of people in each of the affected states and worldwide who rely on our oceans and waterways for their livelihood - to work with others in the industry, with Congress and with all involved federal agencies to make sure that such an incident never happens again.