reply to post by StealthyKat
[atsimg]http://files.abovetopsecret.com/images/member/891d30fed366.jpg[/atsimg]
I do not know if they were injecting dispersant, they were sure expecting the seabed to heave and burst. I cannot see the coordinates clearly but I
think this is quite close to Well A, along the fault line. This place must have been blowing quite regularly for them to be ready to record the
event.
Looks like the ROV operators had been told under strict order not to tell but they certainly can show. So at least some of them want to leak out to
the world what BP doesn’t want to tell.
The overall picture here tells me that this area had blown so often, the clayey seabed sediment had been totally replaced by heavy drilling mud. If
you check the earlier seabed you can still see potholes. I will be writing on this "evolution of the seafloor features" shortly illustrating the first
natural seabed features to the current heavy loose seafloor.
As the top layer gets heavier, the "dispersed fluid (oil, gas, water, slurry and dispersant)" will have to accumulate till high pressure before
bursting. That's why you see a significant heave before the bubble burst. In an earlier video, the heave was hardly perceptible because the top layer
was less heavy and the sediment less cohesive.
This is a good video to illustrate. You know we can all learn a little bit of sedimentology from all this.
To your question, if the robot was injecting dispersant, no it is not the dispersant causing the seabed to swell and burst. But going back to my
earlier comments, it would be far more effective and economical for them to mix the dispersant inside the well or at least at a deeper level.
I would like to add that in natural seabed, once the top layer is breached, subsequent gas accumulation cannot build up the pressure. Thus you will
find smaller pockmarks within or at the sides of the first “bubble burst” or crater. The size of the crater (which we call pockmark) can be
between 10 to 150 m in diameter depending on the thickness, homogeneity and strength (or cohesiveness). In some odd cases, you will see not circular
but skewed pockmarks but that is another story. Subsequent gas will form pockmark clusters instead. Each pockmark within the cluster is about 3 to 15m
in diameter.
edit on 12-10-2010 by BK Lim because: (no reason given)