I can't tell you for sure exactly what went wrong in the incident in the Gulf of Mexico, but we're all gleaning little bits and pieces. One of the critical elements of failure, we suspect, was with the two-barrier system.
The basic concept of well control maintenance is that you always have two means of keeping the oil and gas pressure contained. One of them is with the drilling fluid; the other is with casing and cement. In the case of the Gulf of Mexico incident, we understand that in the first case, the cement job and the casing job and the bonding of the cement to the wall to give pressure integrity were suspect. While that suspicion existed, they then proceeded to remove--displace--the heavy hydraulic fluid that would contain the pressure as a second barrier. The removal of that second pressure barrier is what prompted the uncontrolled flow.
We don't understand how that could happen, because the drilling program approvals that we have in Canada require that you always maintain two barriers. In Canada, with every daily report and every casing running report, the regulator gets to see and observe the operation that is being carried out on the rig. If you got to the stage of eliminating that second barrier, there would be intervention, from our perspective, from both the crew members who had been trained in basic well control and from the regulator to say that you can't do that.
There's a much closer intervention and a much closer observation with the regulatory bodies, in my experience.