Does anyone have a handle on pounds per square inch of pressure of the flow of oil (mud not heavy enough?) against the pounds per square of sea bed pressure, and then subsequent impact as the flow encounters considerably less pressure the closer to the surface the flow gets?
Update from comments in Oil Drum today:
Reservior quality oil is API 35 (right on edge between light & medium quality crude, few asphaltenes, which make the “best”, longest lasting tar balls) with lots of natural gas (3,000 GOS, 10,000 GOS is considered a gas well). The oil emulsifies with water easily, much better than most crude oils.
The reservoir pressure is 13,000 psi. (Temperature only 180 F from one report, unusually cold). 4 weeks ago the pressure was reported as 8,000 to 9,000 psi entering the BOP and just seawater pressure (@ 2,200 psi) + 400 psi exiting the BOP. This implies much more than just a frictional drop up 13,000′ of drill string, but some obstruction as well.
Since then sand entrained with the gas and oil has eroded the BOP and BP has stated that new observations of BOP pressures were “surprisingly lower” but gave no numerical data. OTOH, downhole, it is normal for wild wells to pull rocks as well as sand into the bore and clog things up.
However, this specific well has cased for production (later), which is designed to prevent being clogged up by produced rock and sand.
My GUESS is that the pressure drop downhole in the well bore is greater and drop across the BOP lower since Thad Allen leaked the pressure #s.
This also implies that the clogging the holes spewing that we can see does nothing, since they represent just a 400 psi drop. Raise that to 1,000 psi by reducing the size and that will feed back SLIGHTLY to the other, larger pressure drops.
One interesting observation is that the natural gas is dissolved in a super-critical fluid in the reservoir and begins to comes out of solution as it transits the BOP. Expanding gas is quite a force.
A major issue is inertia. Roughly 2 ft2 column coming up 13,000′ and a few feet/sec is quite a battering ram. Beyond that is a good sized reservoir. It has been sitting still for the last few million years, and now it begins to flow towards this new hole. Given the size (perhaps 100 million barrels) it will take months for all the oil to start flowing evenly towards the well. But that is another source of inertia which will continue to grow over time.
I am confused (me too) as to whether the Top Kill/Junk Shot is injecting mud & debris where the pressure once was seawater (@ 2,200 psi) + 400 psi or 8,000 to 9,000 psi.
I hope this helps a bit. I personally have very little hope for anything except the relief wells.