Amending my answer for the interest based upon the new law.
D. 1. Except as otherwise provided in paragraph 2 of this subsection, where proceeds from the sale of oil or gas production or some portion of such proceeds are not paid prior to the end of the applicable time periods provided in this section, that portion not timely paid shall earn interest at the rate of twelve percent (12%) per annum to be compounded annually, calculated from the end of the month in which such production is sold until the day paid. 2. a. Where such proceeds are not paid because the title thereto is not marketable, such proceeds shall earn interest at the rate of (i) six percent (6%) per annum to be compounded annually for time periods prior to November 1, 2018, and (ii) the prime interest rate as reported in the Wall Street Journal for time periods on or after November 1, 2018, calculated from the end of the month in which such production was sold until such time as the title to such interest becomes marketable or the holder has received an acceptable affidavit of death and heirship in conformity with Section 67 of Title 16 of the Oklahoma Statutes, or as set forth in subparagraph b of this paragraph. Marketability of title shall be determined in accordance with the then current title examination standards of the Oklahoma Bar Association.