Okla. Stat. tit. 12 § 655
Where the grounds for a new trial could not with reasonable diligence have been discovered before but are discovered more than ten (10) days after the judgment, decree, or appealable order was filed, or where the impossibility of preparing a record for an appeal, without fault of the complaining party, arose more than ten (10) days after the judgment, decree, or appealable order was filed, the application may be made by petition filed in the original case, as in other cases, within thirty (30) days after such discovery or occurrence; on which a summons shall issue, be returnable and served, or publication made, as in the beginning of civil actions, or service may be made on the attorney of record in the original case. The facts stated in the petition shall be considered as denied without answer, and the case shall be heard and summarily decided after the expiration of twenty (20) days from the date of service and not more than sixty (60) days after service, and the witnesses shall be examined in open court, or their depositions taken as in other cases; but no petition shall be filed more than one (1) year after the filing of the final judgment.
Okla. Stat. tit. 12, § 655