This Article is applicable to all prisoners serving sentences of imprisonment for convictions of impaired driving under N.C. Gen. Stat. § 20-138.1  This Article does not apply to a prisoner serving a sentence of life imprisonment without parole.  A prisoner serving a sentence of life imprisonment without parole shall not be eligible for parole at any time. (1979, c. 760, s. 4; 1979, 2nd Sess., c. 1316, s. 41; 1981, c. 662, s. 3; 1993, c. 538, s. 21; 1994, Ex. Sess., c. 21, s. 2, c. 22, ss. 33, 34, c. 24, s. 14(b).)