Okla. Stat. tit. 57, § 354

Upon the commitment to imprisonment of any prisoner, the Pardon and Parole Board shall cause a continuing study to be made of the prisoner. When the prisoner has served the minimum sentence imposed, or as soon thereafter as he or she can be heard, the Pardon and Parole Board shall hear the application of the prisoner for parole, and shall make such recommendation to the Governor as, in its discretion, the public interest requires.