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View Diary: Daily Kos Gulf Watchers ROV #275 - Cementing in Progress - BP's Gulf Catastrophe (314 comments)

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  •  Some clarification (14+ / 0-)
    1. Static kill will definitely pump cement all the way to the reservoir and fill the voids both below and above the relief well #1 intersection point.  That process has been described and demonstrated in detail. (see July 21 or 22 technical briefing video)
    1. The bottom kill would have filled exactly the same areas, but to get mud and cement up the well casing and DP above the intersection point they would have let the top flow (could capture with upper bop choke/kill lines, or just flow to GOM).  This is part of the reason why bottom kill was a more favorable option when the well was flowing.  The reservoir pressure + mud pressure from the bottom would force mud up the well.  Problem is, the mud volume would have to exceed the oil flow rate by a good margin to ensure more mud than oil going up.   Static kill is attractive because mud flow volume and thus total pressure can be kept low, while no oil flows to GOM.

    After they complete the cementing and it has set, then they'll have plugged at least the casing and the DP, all the way down to the reservoir.   The reason for continuing with the relief well is if they want to ensure that the annulus (void outside the casing) is also sealed rather than just left as a void.   It may already be filling with cement if there is communication between casing and annulus now.  If there is not, then they can drill through the annulus with relief well, and start pumping in cement to create an additional seal between annulus and casing.   They may simply drill through annulus anyway and if they hit cement, they know they're done.

    I suspect the second relief well will be abandoned where it sits now.  They've said that the relief wells are designed differently from a producer and thus cannot be turned into a producer, and there's no need for it to intersect MC252 if cementing from the top and relief well #1 go as planned.

    •  Thank you, daemn42 (10+ / 0-)

      You explained it a lot better than I did in the last ROV. :)

    •  If oil in annulus, as likely, RW's job is harder. (12+ / 0-)

      The question of where the mud and concrete would go coming in from the RW intercept point hasn't been clearly answered.

      What's in the annulus - likely oil since the DP was compromised at several points down to the reservoir (communicating with the annulus as they say) - needs to go somewhere as mud and concrete come in.

      If the annulus isn't sealed with concrete at the bottom where the well is in contact with the reservoir, then the reservoir would flow up it until it reaches a sealed point. That upward flow in the annulus could be into rock formations, or even all the way up the annulus to the surface.

      So, I'm hoping there is a way to have the RW concrete-seal the bottom of the annulus where it contacts the reservoir and would like to hear how that can be done.

      Kos created a site promoting a variety of views & communities; some [believe] they created dKos & it should conform to their image of it. MKSinSA 2/7/10

      by David PA on Thu Aug 05, 2010 at 03:12:00 PM PDT

      [ Parent ]

    •  Though with the capping stack (11+ / 0-)

      they could have modulated the flow, as opposed to pumping mad at a rate to overwhelm free flow. Which of course is moot now.

      •  True, and was probably another factor (9+ / 0-)

        in wanting to get the capping stack on there in the first place.   A bottom kill with a totally uncontrolled well has got to be tricky.

        And yes if we assume for the sake of argument that the annulus was in communication with the casing at some point and now is full of oil, but that the top kill and cementing doesn't fill that void, then there's a question of how to get the oil out, so they could pump cement in from the RW.   But since they intend to cement the casing all the way to the reservoir, that may seal the bottom against reservoir pressure.  In which case when they intercept with the RW, they could simply pump some volume of  oil out of the annulus, then cement back in.   Another possibility is that there's casing damage further up the well (above the cement plug) and pushing cement into the annulus from below will force oil back up to the BOP where they can relieve it.  Another "injectivity" test would answer that.  

        Basically when the RW intercepts the annulus they should see one of:

        1. Annulus at zero relative pressure with no oil, or cement (indicates no damage to casing or bottom seal ever occurred)
        1. Annulus at zero relative pressure with oil in it (indicates that casing or bottom seal was damaged but that cementing has sealed the bottom of the casing and bottom annulus seal against the reservoir pressure)
        1. Annulus full of oil and at high pressure.  (Indicates that cementing from casing failed to plug the bottom seal against the reservoir pressure)
        1. Annulus full of cement.  (Indicates that casing was damaged at possibly multiple depths, and communication between casing and annulus has allowed cement to fill that void)

        In cases 1, 2 and 3, I'd expect they'd try to find some way to push cement into the annulus void.

        •  Agreed (5+ / 0-)
          Recommended by:
          KenBee, CindyMax, David PA, Yasuragi, DawnN

          In cases 1, 2 and 3, I'd expect they'd try to find some way to push cement into the annulus void.

          but they've made that into a tricky proposition in cases 2 and 3 now that any such oil has nowhere to go, except possibly into fissures if they push hard enough to accomplish anything at all.

          I wonder if they can inject air to force the oil down. Is that what they would find in the annulus in case 1? Air?

          •  Actually (2+ / 0-)
            Recommended by:
            i m bobo, KenBee

            In case 2, they should be able to pull some oil out of the relief well and replace with cement.
            In case 3, there's communication from annulus to reservoir, so they can just push cement in, and it'll reach down and plug the communication point between annulus and reservoir.  

            •  If it's case 3, the most likely case, saying that (0+ / 0-)

              the well is killed now is not correct.

              If you push mud or cement in through the RW in the case 3 scenario you would have to increase the pressure in the annulus above the RW inception point before you could push cement down into the reservoir. There may be significant amount of risk in doing that.

              This is why cementing from the top was a bad idea because it removed the possibility of oil flow up the annulus, which would have made the process of pushing in mud or cement through the RW to seal the annulus to the reservoir much less risky.

              Kos created a site promoting a variety of views & communities; some [believe] they created dKos & it should conform to their image of it. MKSinSA 2/7/10

              by David PA on Thu Aug 05, 2010 at 10:10:04 PM PDT

              [ Parent ]

          •  and maybe back to using the second relief well (2+ / 0-)
            Recommended by:
            i m bobo, Yasuragi

            as the region Outside the casing can be flowed between them,....unless there is reservoir pressure, then perhaps that would be even more of a reason to use the second well...letting reservoir pressure outside there, with no real knowledge of how high the pressure goes would not be a safe well kill, right?

            Dam BP corner cutting weaselly mofos.

            great explanations y'all..I mean ya'll, thanks very much.

            Homer Simp here, forgot that the annulus is the outside of the casing, not between the casing and the drill pipe..or something.

            So do they cement outside first and then drill thru the casing to cement the insides? 1" steel, a mile down...wowee, that's some drill process.

            Crikey.

            Does this rec make my head look fat?

            by KenBee on Thu Aug 05, 2010 at 07:48:17 PM PDT

            [ Parent ]

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