I just want to be clear that this is a map I made using the ITG information as a base map. I would be happy to discuss my findings.
Awesome conversation on this subject! A matter of physics. Gas flows very freely, little weight (mass). Doesn't take much pressure to move. Oil, thicker and has weight (mass again). Try to move it through too much pipe, no flow. In other words, when the resistance to flow and the weigh of the oil equal the pressure, it stays put. It won't flow. With water at about 0.33 lbs per foot of depth, oil being lighter at, lets say, 0.3 lbs per foot, a well 10,000 feet deep and with 10,000 psi will push the 3,000 lbs of the weigh of the oil (10,000 ft X 0.3 lbs) to the surface if the pipe is large enough to overcome the resistance to flow. Trouble is, the oil is shallow and the pressure not high enough to overcome the weight, let alone the resistance to flow. Ok, use artificial lift. That is exactly what GE is working on in a research lab out in TX or OK, somewhere... Conventional lift on a horizontal? Sucker rod scraping on the side of a 90 degree turn? Good luck! A couple of things I can think of might help. Ultrasonic vibrations make liquids flow with less resistance. This might work where the pressure is greater than the weight but the oil won't flow due to the resistance. But, if the drillers can connect a vertical to the horizontal at a point not higher than the average horizontal depth, AND use ultra sound, they could use a conventional artificial lift successfully. They will figure it out. I have no doubt about that!
Pressure is only part of the story. As you proceed down the API scale toward the oiler end of the spectrum, the CH molecules simply become larger than the pore spaces through which they need to travel. At the molecular level, if the rock is too tight, no amount of pressure will move a square peg thru a round hole.
Let me throw this at you