W. Va. Code § 11-1C-10
(a) As used in this section:
"Industrial property" means real and personal property integrated as a functioning unit intended for the assembling, processing and manufacturing of finished or partially finished products.
"Natural resources property" means coal, oil, natural gas, limestone, fireclay, dolomite, sandstone, shale, sand and gravel, salt, lead, zinc, manganese, iron ore, radioactive minerals, oil shale, managed timberland as defined in section two of this article, and other minerals.
(d) Within three years of the approval date of the plan required for natural resources property required pursuant to subsection (e) of this section, the State Tax Commissioner shall determine the fair market value of all natural resources property in the state and thereafter maintain accurate values for all such property.
(3) Property producing oil, natural gas, natural gas liquids.
(B) For the purposes of this subdivision:
(C)
(i) For all assessments made on or after July 1, 2022, the valuation of property producing oil, natural gas, natural gas liquids, or any combination thereof shall be calculated using a yield capitalization model. The yield capitalization model shall be composed of a working interest model and a royalty interest model. The summation of the working interest model and the royalty interest model shall represent the fair market value of the property.
(I) The working interest model shall be calculated as the sum of the working interest net proceeds income series for natural gas, oil, and natural gas liquids. The net proceeds income series shall be calculated as a terminating series of net proceeds discounted by applying a capitalization rate multiplier and a decline rate multiplier. The initial term of the terminating series of net proceeds shall be the net proceeds for that product multiplied by a six month capitalization rate multiplier and an eighteen month decline rate multiplier.
In each subsequent term of the net proceeds income series, the calculation shall use the value from the previous term and multiply that term by a capitalization rate multiplier and an applicable twelve-month decline rate multiplier.
(II) The royalty interest model shall be calculated as the sum of the royalty interest receipts income series for natural gas, oil, and natural gas liquids. The royalty interest receipts income series shall be calculated as a terminating series of royalty interest receipts discounted by applying a capitalization rate multiplier and a decline rate multiplier. The initial term of the terminating series of royalty interest receipts shall be the royalty interest receipts for that product multiplied by a six month capitalization rate multiplier and an 18 month decline rate multiplier.
In each subsequent term of the royalty interest receipts income series, the calculation shall use the value from the previous term and multiply that term by a capitalization rate multiplier and an applicable 12-month decline rate multiplier.