Welcome to the forum. Your royalties will depend upon your net mineral acres. the size of the drilling unit spacing.your royalty and how your acreage or feet of perforation contribute to the well, price of products and volume produced. In Oklahoma, the equation is net mineral acres/actual spacing acres x royalty x percentage of perforations in your section. Texas is a similar but depends upon if you have a allocation well or a pooled well. If your lease says 80 acres on it, that may be a gross acreage and not your net acres.
For OK, an example of 80 acres at 20% royalty and 1280 spacing would give the following decimal.
80/1280 x .20 x 1.0 =0.0125. That decimal is multiplied against the operator’s gross sales receipts every month (minus any taxes or deductions your lease allows). The well volume declines over time, so the early months have the highest volumes.