Unless the context otherwise requires, the definitions set forth in this section shall govern the construction of this chapter.
§ 1203.51.Definitions
Title 4. Of the Enforcement of Liens · Chapter 2.5. Oil and Gas Liens · Last amended 1995 · Last verified July 29, 2026
In one sentenceSection 1203.51 defines eleven terms used throughout the Oil and Gas Lien Act, including who counts as an owner, what counts as material, and how labor differs from services, drilling, operating, and construction.
Full Text of § 1203.51
(a) "Person" means an individual, corporation, firm, partnership, limited liability company, or association.
(b) "Owner" means a person holding any interest in the legal or equitable title or both to any leasehold for oil or gas purposes, or his or her agent and shall include purchasers under executory contract, receivers, and trustees.
(c) "Contract" means a contract, written or oral, express or implied, or partly express and partly implied, or executory or executed, or partly executory and partly executed.
(d) "Material" means any material, machinery, appliances, buildings, structures, casing, tanks, pipelines, tools, bits, or other equipment or supplies but does not include rigs or hoists or their integral component parts except wire lines.
(e) "Labor" means work performed in return for wages.
(f) "Services" means work performed exclusive of labor, including the hauling of material, whether or not involving the furnishing of material.
(g) "Furnish" means sell or rent.
(h) "Drilling" means drilling, digging, shooting, torpedoing, perforating, fracturing, testing, logging, acidizing, cementing, completing or repairing.
(i) "Operating" means all operations conducted on the lease in connection with or necessary to the production of oil or gas, either in the development thereof or in working thereon by the subtractive process.
(j) "Construction" means construction, maintenance, operation, or repair, either in the development thereof or in working thereon by the subtractive process.
Plain-English Summary
Because the Oil and Gas Lien Act uses several words in a specialized way, this section pins down their meaning before the operative sections rely on them. "Owner" is defined broadly — anyone holding legal or equitable title, or both, to a leasehold for oil or gas purposes, including that person's agent, and reaching purchasers under an executory contract, receivers, and trustees. "Contract" is defined just as broadly, covering written or oral, express or implied, executed or executory agreements in any combination.
"Material" covers equipment and supplies used in oil and gas work — machinery, casing, tanks, pipelines, tools, and the like — but pointedly excludes drilling rigs and hoists, except for their wire lines. "Labor" means work performed for wages, while "services" means work performed apart from labor, including hauling material whether or not that hauling also involves furnishing the material. "Furnish" means to sell or rent.
The remaining definitions describe the kinds of oilfield activity the Act covers: "drilling" spans everything from drilling and digging to fracturing, testing, and cementing; "operating" covers operations connected to producing oil or gas; and "construction" covers maintenance, operation, or repair connected with that production. Finally, "original contractor" identifies the person for whose benefit § 1203.52 grants a lien — the party at the top of the contracting chain that § 1203.54's subcontractor lien later builds on.
Frequently Asked Questions
Does "material" under this chapter include a drilling rig?
No. Section 1203.51(d) expressly excludes rigs and hoists from the definition of material, except for their wire lines.
Who counts as an "owner" of a leasehold under the Oil and Gas Lien Act?
Anyone holding legal or equitable title, or both, to a leasehold for oil or gas purposes, or that person's agent, including purchasers under an executory contract, receivers, and trustees.
What's the difference between "labor" and "services" in this chapter?
"Labor" means work performed in return for wages. "Services" means work performed apart from labor, including hauling material, whether or not that work also involves furnishing the material.
What does "furnish" mean under this chapter?
To sell or to rent, as § 1203.51(g) defines it.
Who is the "original contractor" referenced throughout this chapter?
Amendment History
Amended by Stats. 1994, Ch. 1010, Sec. 62. Effective January 1, 1995.
Source & verification. Section text is reproduced verbatim from
the Deering's California Codes Annotated / vLex. Enacted by the California Legislature.
Last verified July 29, 2026.
· Official source
Also known as: oil and gas lien act definitions californiaoriginal contractor definition california oil and gas lien