Hi mincdg,
Although it’s still in process (and I don’t work for them), mineraliq.com will (in the near future) be providing that service for free to mineral rights owners. They are connected with Enverus (EnergyLink.com), who provides the online check stub detail for numerous oil companies.
When it’s completed, you should be able to see how much your wells (and portfolio) is worth, and you’ll be able to sell to buyers with the highest offer. There’s no obligation to sell (obviously); it’s just a way for mineral owners to have a better view of their data, and to connect them in a closer way with any interested buyers.
MineraliQ still has some bugs and issues, but it can be a very helpful way to view your properties/wells, where they’re located on the map, what kind of activity is taking place nearby, etc. It’s worth taking a look!
I hope this helps!
Greg