Mineral Leases in Osage County: Value and Market

I have three oil and gas leases in Osage County, each of 160 acres. How are such leases valued? I am away that there is a link to “Mineral Auction” on this site, but I need to understand what the lease is worth for allocation in my will, and to decide how to sell one or more if it proves simpler and less prone to disputes among heirs. Any ideas? Recommendations? Wisdom I should acquire?