Decimal interest

I inherited mineral rights from my mother in 2021 in Ellis county Oklahoma. I received two division orders today and the decimal interest on the orders is not the same as my mom’s was. Should it be? Any help is appreciated.

Are they for the same wells? Same unit?

Different wells. I was comparing to documents from 2011.

The division order decimal interest is derived by dividing your net mineral acres by the gross acres in a unit times the royalty interest set out in your lease. Your mother’s division order interest was most likely in 40, 160 or 640 acre units. Most wells drilled in Ellis County today are being drilled on larger units (1280 acres or more). Therefore the interest you are seeing is most likely smaller than the ones set out on your mother’s devision orders.

Do you know if the allocation values on her sections were 100%? Are they for same section? If so, a deeper well could be allocated differntly if its part of a multi unit well? Are you factoring in her OGL royalty? For example, 10 acres in a 640 acre unit would be 0.015625% interest, but then you have to factor in the lease royalty, so say its a 3/16th or 0.1875 x 0.015625= 0.002929%

Thank you both. Both of your answers have made this make sense!