California Code, Code of Civil Procedure - CCP § 1203.53

(a) The leasehold for oil or gas purposes to which the materials or services were furnished, or for which the labor was performed, and the appurtenances thereunto belonging, exclusive of any and all royalty interest, overriding interests and production payments created by an instrument recorded prior to the date such materials or services were first furnished or such labor was first performed for which lien is claimed; and

(b) All materials and fixtures owned by the owner or owners of such leasehold and used or employed, or furnished to be used or employed in the drilling or operating of any oil or gas well located thereon; and

(c) All oil or gas wells located on such leasehold, and the oil or gas produced therefrom, and the proceeds thereof, except the interest therein owned by the owners of royalty interests, overriding royalty interests and production payments created by an instrument recorded prior to the date such materials or services were first furnished or such labor was first performed for which the lien is claimed.