________________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Nick Arnett Sent: Monday, May 03, 2010 9:11 AM To: Killer Bs (David Brin et al) Discussion Subject: Re: On Listmail
On Sun, May 2, 2010 at 10:49 PM, Doug Pensinger <[email protected]> wrote: If anything good is to come out of this disaster, its that we'll be taking a closer look at offshore drilling, and that nobody will even be suggesting that we rape the California coast for a few buckets of oil. I've seen people seriously speculating that anti-drilling people, perhaps directed by the White House, sabotaged the platform, to cause the spill, so that drilling would slow down or stop. There is no end to the conspiracy. >On a more rational note, DB commented that every well should have a deadman switch, so to speak - a device that shuts off the flow if it doesn't continuously receive a signal. Maybe I'm naive, but it >seems to me that something like that would be in place if it were practical. Anybody know? I do. I happen to know a decent amount about the rules and regulations concerning this. They are quite strict, and cover everything folks could think of. If what I'm hearing from a _very_ well placed source on what is known about what happened is right, this will turn out to be a black swan event. Reasons for it are speculative right now, and I won't say one way or the other in a list that turns up in Google searches who I think might have done something wrong, but we do know some things. >From what I've heard, there were two independent cutoffs; either one of which should have been sufficient. They are a mile below the water, so the explosion at the surface is not the likely cause for them not tripping. My memory of blowout prevention is that there are two means of the cutoffs being triggered; one automatic, and one switched. The switch has been pulled a zillion times, both remotely and from subs right at where the well comes out of the ground. No dice. I have heard that the bottom casing came out at the surface. The casing is the steel pipe that's cemented into place in the borehole to allow the pumping of oil from the horizontal section of the well (I haven't read, but would bet $100 to $1 that this well was highly deviated and if not horizontal at the bottom, it wasn't only because the producing bed was tilted and it was following the tilt....so call it horizontal. So, whatever happened is something my source said he would have bet his house would be impossible: casing pushed to the surface by gas pressure. First, the casing should have been held in place by the cement (think of pulling rebar out of a piece of concrete from a chuck of, say, a collapsed bridge). Second, the casing is torqued together, and the gas pressure isn't a torquing pressure, so I'd guess tons of casing would have had to make it to the surface. Under those conditions, I can imagine damage to the cut-offs. No one could have envisioned, after already drilling the well and measuring all the downhole pressures, that during well changeover, there'd be enough pressure to push that much drill pipe out....and that the drill pipe wouldn't be held by the cement. 11 people died. Most lived, so the problem wasn't that the cutoff could not be triggered because the guy who could do it died. In fact, both cutoffs were triggered repeatedly, and neither worked. No one knows for sure, but I'd put money on both cutoffs being damaged, not by the gas, but by the casing going up. BTW, I bet the rig was running intrinsically safe. The rules for running that way are very strict; a normal computer is not intrinsically safe; a 6 volt battery isn't, etc. Making an intrinsically safe computer requires an air tight box, so any possible spark from the computer couldn't reach the open air. IIRC, the biggest voltage/amperage allowed would be far below the threshold for the smallest spark possible. But, push casing 6 miles up through earth and ocean and have it break and fall on the rig, and you have a spark, and that's all she wrote. But, having this happen boggles the mind. Dan M. _______________________________________________ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
