What are the common ownership interest types?

WI. Working Interest: The exclusive right granted to the lessee to explore for and to produce and own the oil and gas located under the lands covered by the oil and gas lease. The working interest owners bear all costs of exploration, development, and operation.

RI. Royalty Interest: Lessor’s share of production as set forth in the oil and gas lease ORRI.

ORRI.Overriding Royalty Interest: A percentage share of production or the value derived from production, which is free of all costs of drilling and producing and is created by the lessee or working interest owner and paid by the lessee or working interest owner.

Usually, the term of an ORRI is for the life of the oil and gas lease.