Legacy Well

A well drilled in an unproven area to determine whether hydrocarbons are present, typically representing higher-risk, shorter-duration work for subcontractors with less certainty of follow-on contracts compared to development drilling programmes. Field service companies should account for the speculative nature of these projects when negotiating mobilisation costs and contract terms.

An intergovernmental organisation that publishes global energy outlooks and demand forecasts, which subcontractors and field service companies use to anticipate shifts in upstream and downstream activity levels that may affect project pipelines and contract opportunities.

Offshore operating zones typically under 500 feet of water depth. For subcontractors, these sites use jack-up rigs and barges rather than deepwater vessels. Crew access, equipment requirements, and mobilisation costs differ significantly from deepwater scopes.

The collection of drilling tools and equipment at the bottom of the drill string, including the drill bit, drill collars, stabilizers, and downhole motors. For drilling subcontractors, BHA configuration directly impacts drilling performance, tool wear rates, and operational efficiency.

A company that provides specialized services to oil and gas operators, such as drilling, completions, workover, transportation, or maintenance. Also called oilfield services (OFS).

A contract between an operator and a service company that establishes the general terms and conditions for all future work. Individual jobs are then executed under work orders or AFEs referencing the MSA.

What Is an AFE in Oil and Gas and How Does It Affect Subcontractor Payments?

An AFE (Authorization for Expenditure) controls every dollar spent on an oilfield project. Learn how it affects your billing, change orders, and cash flow as a subcontractor.