IEA (International Energy Agency)

Underground storage facilities carved out of salt formations or rock, used to hold large volumes of natural gas, crude oil, or other hydrocarbons. Subcontractors handle construction, maintenance, inspection, and integrity testing at these sites, often needing confined-space and geotechnical certifications. Injection and withdrawal seasons create predictable maintenance windows, helping field service companies plan mobilisation.

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.

To create precisely spaced holes or openings in oil well casing and cement at a target formation depth, allowing hydrocarbons to flow into the wellbore; subcontractors providing perforating services typically work under wireline or coiled tubing crews and must coordinate closely with the operator's completion schedule.

The formal handover point where ownership or responsibility for a measured quantity of oil, gas, or other product moves from one party to another — typically triggering billing, invoicing, or contractual obligations for subcontractors involved in metering, transport, or handling operations. Field service crews working custody transfer points must ensure measurements are accurate and fully documented, as discrepancies can directly affect client invoices and liability.

Provincial agencies in Canada that provide workplace injury insurance. Contractors must maintain WCB coverage and good standing to work on most sites.

The straight-line vertical distance from surface to a specific point in a wellbore, regardless of how the well is drilled — subcontractors working on directional or horizontal wells need to reference TVD (not measured depth) when scoping equipment reach, calculating hydrostatic pressures, or verifying work zone depths on service orders.

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.