Oregon Revised Statutes Public Lands § 274.840

In the event production on the leasehold shall cease at any time or from time to time, before or after the expiration of the primary term of the lease, the lease shall nevertheless continue in full force and effect if the lessee shall, within six months after the cessation of production or within such longer period of time as the Department of State Lands may authorize, commence and thereafter prosecute with reasonable diligence drilling, deepening, repairing, redrilling or other operations for the restoration of production of oil, gas or sulfur from the leased lands.