Okla. Stat. tit. 17, § 17-511: Liability of owner or lessee - Liens

The obligation or liability of the lessee or other owners of

rights in the several separately owned tracts for payment of unit

expense shall at all times be several and not joint. At no time

shall a lessee or other owner of rights in a separately owned tract

be chargeable with, directly or indirectly, more than the amount

apportioned to its interest in such separately owned tract pursuant

to the plan of unitization.

Subject to such reasonable limitations as may be set out in the

plan of unitization, the operator shall have a first and prior lien

upon the leasehold estate in and to each separately owned tract and

the interest of the owners therein in and to the unit production and

equipment in possession of the unit, to secure the payment of unit

expense charged to such separately owned tract.