[QUOTE=Earl Boebert;48654]Oh, sigh, here we go again. I’ve been involved in a lot of after-incident exercises (though none of this scale) and one lesson I have learned is that you can solve the mystery of what happened, or you can apportion blame, but it’s almost never that you can do both. I think the BOP situation illustrates this dichotomy the best. The pressure by the lawyers to find a single culprit (other than their client) means a lot of emphasis on things like maintenance failures. This diverts attention from what I think is the real necessity, which is to rethink and re-engineer the whole process of blowout prevention from scratch, using something more advanced than a 1950s era architecture.
We can go round and round forever on the issue of blame; my personal take is that it’s like The Murder on the Orient Express: they all did it. Having said that, I think its really the job of a professional forum like this to focus on the mysteries, in particular, how a trained and experienced crew could miss the volume and pressure readings. In trying to sort out the timelines, I came up with a question I couldn’t answer from the various reports: what was the point of no return? At what hour and minute value (or range) would you say that there was no longer a reasonable chance of successfully activating the BOP? Was it before or after the negative pressure test?
Cheers,
Earl[/QUOTE]
Earl,
The questions you are asking are essential to the prevention of blowouts. We all have designated responsibilities on the vessel. The OIM is the ultimate figurehead regarding safety and determining whether operations can be achieved, safely. This essentially means that when BP tell him of their plans he has to either sanction or reject those plans. Furthermore, he has to clarify those plans to his crew, the people on the vessel who conduct all of the activity on a practical level, the doers! In the absence of clear instruction he is supposed to intervene in the morning meetings and comment on whether the plans/program can be understood and followed by the crews. My understanding is that the BP program is now considered to be less than informative! With this in mind, I wonder why he didn’t ensure that the method of performing the negative test wasn’t clarified. It appears as if he had a laissez faire attitude, allowing the crews and Toolpusher to conduct the negative test the way they ‘assumed’ it should be done, until BP interrupted proceedings to ensure both the Kill line and drill pipe had communication.
Now, some people have suggested that these crews didn’t receive the correct training to perform this type of testing procedure. Horse! The Toolpusher on nights was to become a TO Well Control Supervisor teaching others how to behave in the event of a ‘kick’ (hydrocarbons entering the well). Simply put, they got this wrong on all counts.
So how does a trained crew miss the volume and pressure readings? They simply made mistakes which led to further mistakes. But, they also ignored volume control in the planning phase, and this comes back to haunt the OIM, the responsible person for the safety of the vessel and all activities.
How do we prevent hydrocarbons entering the well on a negative test? We line up to Halliburton cement unit and bleed off in stages to ensure no build-up of pressure is observed after shutting in. So, we bleed off from 1400 psi to 1000 psi, hold for 2 mins, bleed off to 500 psi and hold for 2 mins and then bleed off all the way…BUT, only if the calculated volume back is correct. In the case of the Macondo they bled off twice through the drill pipe and had considerably more volume back than they should have had and then allowed build-up and further bleeding off. It is very alarming to know that no-one from BP or TO realised how important tracking volumes is. The indication was that the cement job had already failed, and no-one understood this fact. This is the most alarming thing to industry professionals.
Worse than this was the fact that the process was continued on the Kill Line and even though no flow was taking place on the kill side the Drill pipe pressure still showed 1200-1400 psi.
No blowout has occurred at this point. Remedies are available if it’s recognised that problems exist. But, no-one is able to interpret the data and this is an unbelievable scenario to believe by myself and the offshore industry professionals. This well simply has an issue with cement, the same as 10-15% of cement jobs completed in Reservoir sections.
When the negative test was accepted the Annular was opened allowing an ‘overbalance’ to exist once more and pumping of SW resumed to displace the mud and Heavy Pill out of the Riser with the well becoming underbalanced. BUT, no control of volumes existed and if volumes had been monitored, as is the normal practice, volume discrepancies would have caused the crew to shut in. Instead, they ran ‘blind’, and did not control volumes or interpret pressure correctly. They could have shut in at any time if competent interpretation had been made of the pressure readings alone. The logger called the Df to ask about monitoring volumes and was told by the A/D that they’d get back to him when normal monitoring could be resumed. This aspect of monitoring is supposed to be planned and controlled in advance of the operation. It has been suggested that no efficient monitoring existed for 7 hours prior to the explosions.
So, what part have BP in this and what part is TO’s? Both failed the negative test interpretation with no plan in place on how to perform it. Who’s responsible? BP offshore planning and the OIM for not stopping the job in the planning phase, until something concrete was arrived at. The OIM sanctions all activity…and interrupts when procedures are not in place. He did not interrupt!
The displacement is a TO/Swaco/logger issue where volume control had to be ensured. Volumes were ignored and the OIM has to answer for it.
And, the opportunity to see if the well was flowing or not was ignored during the sheen test. This is a TO duty and it was apparently left to observation by video!! The well was flowing and it only required a responsible person to check for flow. Shut-in could have been activated there and then…but, they’d still have a massive volume of gas in the well to resolve. Nevertheless, there wouldn’t be 11 dead.
As to the question when is too late to shut in the Rams/BOPs? Hydraulic shock may occur with the ejection of mud/hydrocarbons from the well and this is very late to be closing in. It has been suggested that the well was closed in after the first explosion. Ideally, the well should be shut in early, but it is supposed to be able to seal in a dynamic situation and there are well blowouts which have been stopped by activating the Shear Rams with full wellhead pressure and flow taking place.