Cal. Pub. Resources Code § 3330
When unit expenses incurred by a unit operator on behalf of the unit have not been paid, the unit operator may, in order to secure payment of the amount due the unit operator, fix a lien upon the interest of the debtor in all drilling and production equipment of the debtor on the premises and upon his allocated portion of 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 (1) in general terms the kind of materials, tools, equipment or supplies furnished, labor or services performed, or expenditure incurred, and (2) a description of the land involved, the name of the debtor and his interest in the production from the unit area, and (3) the amount which is still due and unpaid, and (4) a statement that at least 20 days prior to the date of the affidavit the unit operator gave written notice to the debtor by registered mail at his last known address, setting forth the information required under subdivisions (1), (2) and (3) above. 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 or the incurring of the expenditure. The lien shall not be construed as constituting a lien upon real property as such, except as to the recoverable oil and gas lying thereunder, but otherwise shall be of the same nature and subject to foreclosure in the same manner and within the same time as mechanics' liens. In any case where a unit operator is in possession of the production which is subject to the lien, he may sell such production or so much thereof as may be necessary to satisfy said lien; provided, that he shall hold or arrange for the holding of the proceeds of such sale for appropriate distribution upon the determination of the controversy.
Ca. Pub. Res. Code § 3330