Cal. Public Resources Code § 3680

A person to whom another is indebted for expenses incurred in carrying on unit operations may, in order to secure payment of the amount due, fix a lien upon the interest of the debtor in the unit production as and when produced from the unit area by filing for record with the recorder of the county where the property or a portion thereof involved is located, an affidavit setting forth all of the following: (a) In general terms the kind of materials, tools, equipment, or supplies furnished or labor or services performed. (b) A description of the land involved, the name of the debtor, and his interest in the production from the unit area. (c) The amount which is still due and unpaid. (d) A statement that at least 20 days prior to the date of the affidavit such person gave written notice to the debtor by registered mail at his last known address, setting forth the information required under subdivisions (a), (b), and (c) of this section. Any such affidavit shall be filed for record not later than 90 days after the delivery of the property or the completion of the labor.