In particular foreign private oil companies have a long history of not paying adequate royalties to the countries they operate in (which is the reason they get nationalized after popular revolts). Even the US govt sued Exxon in Alabama for systematically underpaying royalties (they lost, but whatever).
What do you think is a "fair" amount of royalties to pay?
In my opinion, whoever owns the land should get 100% of whatever income they can derive from it. If Shell wants to buy some land, they should own whatever oil they can suck up from under it.