As well as I can remember, when they were building a new bridge years ago on a highway over the inland islands here in California, I was driving a cement truck at the time. And they had to ‘pour’ cement pillars for the new bridge, A solid frame with rebar on the interior was built for the pillars, then when we arrived at the site with ready mix cement, and before they started pouring the cement, we added so much water to the ready mix it was at almost to a point of being liquid. itself, not including the water that was inside the framework of the pillar form. The forms were about 200ft or better from riverbed to the top.
This was the formula that was used to get cement to the complete bottom of the riverbed that it needed to settle on, As the form filled to about the half way point, the consistency of the ready mix was increased so that the weight would push down and make the thinner slump to solidify, Thus. making a strong pillar for the bridges weight. I don’t see any reason that they could not apply the same principal to pouring cement into the ‘straw pipe’ on the oil leak and sealing it off in the same manner, But, that’s just my opinion. Maybe they have already thought of that, or have tried it . Instead of trying to build a dome to cover the leak and and siphon it into a pipe to bring it to the surface to a waiting ship .
Now try to do that with no “bottom” at the bottom of the pillar… . just a huge cavern. There lies the problem. While they had the well intact, they could put tools down in the well to block the flow, inject whatever they wanted at a specific place. But now they have a straw open on both ends, and no way to put their finger on either end. Someone from BP described it after my prior post as “a tug of war with very high pressures”. Keep in mind what made this blow in the first place – methane leaked in through the casing (current suspiciion) – as they withdrew the mud, the pressure on the methane dropped and it changed form explosively (liquid to gas? ) and went from 30 degree water on the outside to 80 degree… The sudden pressure change caused it to expel all of the mud out the top of the well and then the gas ignited. Nothing about that situation has changed. If they misjudge and the same thing happens, things could get very ugly. They’ve said that if this fails, it could end up making things worse. One scenario I’ve heard is that the BOP might be blown off the well casing, then leaving no impediment to a non-stop flow until the well loses pressure. The very similar one in Mexico in 1979 back leaked for 8 months – and it was only in 170 feet of water…
uh-oh…… the update is that they have now got the well close to balanced with the weight for the mud vs the pressure from below – they are doing the “junk shot” in this configuration to try to inject “stuff” upward into the BOP so that one end of that straw is closed.
The uh-oh is the ship on the surface ran out of mud. A second ship is “on the way” with more. I hope the LA Times just misunderstood what they were being told. Unless there is a physical block in the way, even though the pressure may be even, the mud is going to continue to sink into the oil cavern (during the blowout, one of the signs of trouble was a sudden flow of mud going down the casing into the well). To keep the pressure balanced, you have to keep pumping in more mud to make up what you’re losing out the bottom. While that space is under pressure and isn’t infinite in size, the mud will never “full” it up in the quantities they are using. They have to get a plug in place while mud is still sinking.
If they pump in concrete and it doesn’t get enough of a grip on the casing, when they stop pumping the mud in, the concrete could still rocket up the shaft and hit the BOP. Remember that the pipe gets bigger as you get closer to the surface – think ice cream cone. I’m loking at the ROV video, and it doesn’t look much different than it did this morning. It’s possible I’m seeing mud coming out the BOP instead of oil/gas, but I wouldn’t bet on it.
NY Times reports they have temporarily suspended the Top Kill – too much mud is leaking out (the story doesn’t say if it is out the top or the bottom – but I suspect the bottom for the reasons above)…. As the mud goes down, it’s going to pick up momentum… and start drawing the mud above it downward…. like lowering a long rope off a cliff – the further down it goes the more weight it has wanting to go down….. if you stop pumping in the mud, it doesn’t stop what is already in the pipe from continuing to head down.
I strongly suspect by tomorrow they will be on plan “B” – cutteg off the riser pipe. Get a nice level round opening, and then reconnect a new riser or put a new valve on the top.
Two related thoughts – bringing in “experts” who are used to fighting oil fires above ground was probably a bad idea. They’re applying what they know to a situation they don’t understand. 5,000 feet of hydrostatic pressure is not insignificant.
Thinking through my above scenario, my suspicion about the failure of the BOP – if a large chunk of concrete went upwards as it gave way, it strikes me as likely the ram failed (in part) due to there being concrete in the way. It was desiged to cut through the pipe, concrete inside might not have been expected….
One loose end was that the day after this, John Batchelor had heard a rumor that the reason for the failure was that there were tools in well being used to set the concrete, and the ram jammed because it was designed to cut an empty pipe…
We live in interesting times.
Our President is acting like a puppy who pooped on the carpet. The more people try to put his nose in the mess, the more he reacts with “What? I didn’t do this….”