Supporting evidence for this is when a company drains an old field and comes back 10 or 20 years later to suck up any residue, they sometimes find that oil has seeped up into the empty spaces, filling up the previously-empty reservior with oil that is geologically younger than the previously-extracted oil. This is counter intuitive, since oil at a lower level should actually be OLDER than the oil on top of it. Wierd.
I don't profess to know anything about it except what I have just explained, and several old oil men have laughed loudly when I mentioned the theory to them. Still, it would be cool.
>>This is counter intuitive, since oil at a lower level should actually be OLDER than the oil on top of it. Wierd.<<
Unless the new stuff is seeping up from underneath.
But at this point, and to us lay people it is just, as you said, weird.
“I work in oil and gas. There is a theory called The Abiotic Theory that says oil is not created from fossils and dinosaurs and stuff, but rather earth processes.
Supporting evidence for this is when a company drains an old field and comes back 10 or 20 years later to suck up any residue, they sometimes find that oil has seeped up into the empty spaces, filling up the previously-empty reservior with oil that is geologically younger than the previously-extracted oil. This is counter intuitive, since oil at a lower level should actually be OLDER than the oil on top of it. Wierd.”
Oil/gas can migrate within/along reservoir layers, from high pressure, to low pressure areas.
Primary recovery doesn’t “drain” a reservoir. It takes perhaps 5 - 15%.
Water, natural gas, air injection, (secondary recovery) augments this process by increasing pressure, and fluid movement/migration.
Seconday recovery may yield total production of up to 50% of the original oil in place.
Tertiary recovery might get another 15%, leaving 35% that is never recovered.
* disclosure - my knowledge is from technology 35 years ago. I worked in secondary recovery and reservoir engineering, with post grad. level engineers and geologists.
http://en.wikipedia.org/wiki/Abiogenic_petroleum_origin