California Code, Code of Civil Procedure - CCP § 1203.59

Anything in this chapter to the contrary notwithstanding, any lien claimed by virtue of this chapter, insofar as it may extend to oil or gas or the proceeds of the sale of oil or gas, shall not be effective against any purchaser of such oil or gas until written notice of such claim has been delivered to such purchaser. Such notice shall state the name of the claimant, his address, the amount for which the lien is claimed, and a description of the leasehold upon which the lien is claimed. Such notice shall be delivered personally to the purchaser or by registered letter or certified mail. Upon receipt of such notice the purchaser shall withhold payments for such oil or gas runs to the extent of the lien amount claimed until delivery of notice in writing that the claim has been paid. The funds so withheld by the purchaser shall be used in payment of the lien judgment upon foreclosure. The lien claimant shall within 10 days give notice in writing that the claim has been paid.