1. Production History - (Decline Curves and Water Rates) of the Field and/or Leases
2. Operators Reputation - Some just get it done better than others.
3. Reservoir Formation - Some Reservoirs have longer production histories than others
4. Commodity Price Risk - Gas, Oil, or both - is it sour, treated, etc.
5. Future Production and Development
6. Interest Type - Royalty, Overriding Royalty, Mineral Rights and Interest, Non-Participating Royalty Interest, or Working Interest.
7. Historical Cash Flows and Averages for: 12 months, 6 months, and 3 months.
8. Tax Rates - Tax Rates for Purchase and Severance may be too high, low, or non-existent pending your state of where the interest is located, which affects a properties value and offer rate.
Normally, the information above is used to calculate current reserves with a prediction of future reserves and cash flows. The objective is to offer fair market value while addressing risks and uncertainties that may be involved in future interests and commodities prices.