Full text
any right to a rental or royalty computed by reference to the amount or value of production from an oil or gas well in that country, or from a natural accumulation of petroleum or natural gas in that country, if the payer of the rental or royalty has an interest in, or for civil law a right in, the well or accumulation, as the case may be, and 90% or more of the rental or royalty is payable out of, or from the proceeds of, the production from the well or accumulation,