FPSO (Floating Production, Storage and Offloading Unit)

Occupational Safety and Health Administration. The US federal agency responsible for workplace safety regulations. Compliance with OSHA standards is required for contractors working in the United States.

A safety and compliance management system used by some operators to pre-qualify and manage contractors working on their sites.

The upstream segment of the oil and gas industry covering the search for and extraction of hydrocarbons, representing the primary client base that hires field service subcontractors for drilling, completions, well servicing, and site construction work. Understanding whether a client operates in E&P helps subcontractors anticipate project cycles, budget timing, and the boom-and-bust demand patterns that directly affect contract volumes and payment schedules.

A well drilled in an unproven or lightly tested area to determine whether hydrocarbons are present, often representing shorter-term, high-mobilisation contracts for subcontractors with less predictable follow-on work than development drilling programmes.

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.

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.