[QUOTE=company man 1;34659]During activities invoved in drilling & completion the driller is suposed to keep an account of where the nearest tool joint is in relation to the shear rams. Unfortunately, they were not either drilling or completing. They were kind of in limbo in between. I remember during my first well control school, the teacher was going through the space out of the BOP assembly & we had a long discussion of the stack configuration. My argument was the need to have a redundant set of shear rams set below the choke & kill lines with a mechanism to have lower shears close last. His argument was that there needed to be communication with the well below the shears after shearing so the well could be pumped in on to get back on it after fixing whatever issues led to shearing off the sting. My argument was if you are in a bad enough situation that you have shear off the pipe at the rams, screw the well, you have to consider the safety of the rig & an uncontrolled blowout. I wonder if his thinking is different now? There is no doubt, if there is one need for dhange in regualtion it shold be that a redundant set of shear rams below everything else to minimize the chances of getting a tool joint caught in your rams while shearing off.
If you are triping in or out of the hole & the well comes in there is no sure fire way to make sure you won’t have a tool joint in the shears unless you have redundant shears.[/QUOTE]
Ok, now this makes some sense to me, they just were using the DP (oil well specific vernacular for drill string I now know from this episode) as a tremie pipe (a phrase commonly used in other drilling techniques, but one I have yet to see used as a descriptor in this context), and in that usage, close enough is good enough. Now I imagine that since (apparently) these drill rigs are moving around with tides, wave action, etc. that while drilling the distance from the floor (or whatever reference you have) to the BOP is in flux, so there must be some kind of dynamic compensation for this to keep the pressure stable on the drill string (excuse me DP), or else it will shear off. And I do also understand that when you have thousands of feet of DP in a hole, and thousands of feet to the BOP, and so hundreds/thousands of drill rods (tool joints) in the hole, every little 100th of an inch adds up. But given the great complexity, and great cost of these rigs, you would think that this critical information (where tool joints are) would be tracked by computer and by sensors. Certainly something better than a guy with a notepad stuck in his pocket and pencil behind his ear. Honestly, I would have thought there was a computer display (“cartoon”) of the drill string, with all of this critical information clearly displayed.
As you note, in an emergency, you may not be able to control where the drill string is, you may not have time, it may be stuck etc., so yeah, the BOPs should be manufactured with a redundant set of shears, which are set at an odd distance (15’) apart so to ensure (or at least try to ensure) that they would at least not hit on a tool joint.
But, as pumpjack hand notes, you need to always have a good handle or precise inventory of your drill string (uh, DP, I’ll get the hang of this eventually). for potential fishing operations. Or maybe I should have said “eventual”, or “inevitable” fishing operations?
But one more thing, semi-related. I am a little pissed off at bp for playing the same old, corporate, plausible deniability/non-transparency. Sure, some information is forth-coming, but some (like what pressures and volumes they were pumping are not). Some in the oil drilling industry may put down the experience of other people in other types of drilling operations, but that is pure arrogance and pride getting in the way of what may be a solution that other drilling operations have encountered and solved. cross-discipline expertise is sought out in most every other field, from medicine to computer sciences to (yes) other drilling operations. For people outside that small industry to help, we need more specific information. Shit answers like “the operators can pump at the necessary pressure to get the job done and the work is continuing and we don’t want to distract them by asking questions like that at a time like this” (I paraphrase) which is what Suttle said Friday when asked what pressure and what volume mud they were pumping during top kill are unhelpful and unacceptable.
To boil it down, does anybody out there in the offshore drilling industry fixing this fucking debacle really want to wear their “Ben dar, don dhat, talk to da hand” shirt?