RE: RE: volume29 May 2018 15:47
cjml
16) You mentioned the mechanics of how the gas in a super-critical phase is released and it has a second energy - can you explain that a bit more and maybe relate that to the recovery rates you mentioned above 25%?
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PaulB: If you look at EOG�s reports - and EOG are very clever - if you decompile them, then they�re much higher than what people say. We�re using 17% because that�s well within the range of what�s already been demonstrated. But the recovery factor ultimately is going to be a function of the stress-sensitive permeability. But with respect of the phase itself - it�s a super-critical fluid in other words it�s a gas - but when it gets down to this bubble point, then it starts to release liquids.
People in Eagleford didn�t think Eagleford could work because they thought that as soon as you start producing, the liquids would drop out in a near well-bore area and cause a perm block - and you�d never be able to get the oil out. And that�s a really great theory - but the problem is all that that pressure drop happens within a centimetre of where the fracture is. So that pressure drop is happening within that super-tight rock - and after that you�ve got thousands of psi of flowing pressure and it keeps it in that phase. And so what happens is that drop-out does happen but it happens inside the pore. And when it happens inside the pore, because of the surface chemistry of the pores the gas is adhered to the edges of the pore - and it forces out other things that haven�t gone to gas yet. So what it does is it squeezes it out. Because in volatile oil - which is basically a super-critical gas - there�s actually three different types of oil in volatile oil - there�s condensate, and there�s two types of volatile oil. The only way you can really understand it is if you get into the physics and you�re looking at Feccant(?) curves and all that. But there�s a big difference between our oil and condensate, because our oil has a much higher - it�s C15+. And again, the reason is, because when you get to wet gas, it�s much more mature - all that�s been cracked to the gas. But this hasn�t been cracked, because there hasn't been any cracking done yet. This is all about the kerogen kinetics. It�s just a different base and that�s why it�s been so poorly understood
http://88ewiki.wikidot.com/presentations:09092016-london-transcript
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