Okay, I don't know whether this is a glitch/oversight in Gregtech or PFAA. PFAA worldgen creates four types of oil (listed in NEI as Light/Medium/Heavy/Extra Heavy Oil). They're translating to Gregtech liquids just fine (Light/Raw/Heavy/Very Heavy Oil, respectively), but the only recipes listed in NEI for dealing with Very Heavy Oil are ones to put it in and out of buckets/bottles. By comparison, the other three have a whole range of distillation and refining options (that I'm having a difficult time wrapping my head around, but that's another question entirely.)
Of course, the one PFAA oilfield I've found is of Very Heavy Oil. Is it *supposed* to be useless, or am I just missing something?