Oil fields

[Klaranth]

Marsufoman
I demand oil fields, i dont like having to sell each ores, add insanely rare oil fields to encourage players to explore the world for riches
frog
mars we have oil at home
Marsufoman
i demand proper oil fields
frog
ok what should oil be used for
Marsufoman
money
let us add oil barrels for easy transport

[SwissalpS]

frog
ok what should oil be used for
Marsufoman
money

and what do players use money for? To shortcut the game and not need to put in the actual effort.
To me the reasons of this proposal are contradictory. OP wants to encourage players to run/dig around creating massive amounts of mapblocks to find this insanely rare item only to sell it (presumeably to admin), which is exactly what OP opens up with by saying that they don't like selling ores.
Oil isn't an ore but from game mechanics it's the same to bundle oil into barrels as bundling mese crystals into blocks and then selling them to admin.

Now that mithril and silver aren't as rare as they used to be, I'm interested in the idea of another rare item, but if the only usage is to get money, I'm not interested anymore.

If we use the oil to burn in furnaces and digtrons, that sounds a lot like lava orbs:
very rare fuel.
Only that lava orbs can be obtained without the need of giving mapgen so much work and bloating the database size.

[OgelGames]

To make it worth adding oil and oil fields, there really needs to be a good use for it besides just burning or selling it.

Something like this: https://ftbwiki.org/Refinery_(PneumaticCraft)