Crane Mats

The date when drilling begins on a new well. Marks the start of drilling operations.

The ongoing process of ensuring pipelines remain safe, structurally sound, and compliant with regulatory standards. Subcontractors are frequently hired for inspection, maintenance, and repair work tied to integrity programmes. Scopes can include ILI (Inline Inspection), coating repairs, hydrotesting, and fitness-for-service assessments.

A network of underwater equipment — including wellheads, manifolds, flowlines, and control systems — installed on the seabed to extract and transport oil or gas to a surface facility, representing a specialised scope of subsea installation, inspection, and maintenance work that subcontractors must hold specific certifications and equipment to perform. For field service companies, contracts in this space typically involve saturation diving support, remotely operated vehicle (ROV) operations, or subsea engineering services under strict offshore safety and quality regimes.

A category of ongoing field service work covering routine inspections, preventive maintenance, and corrective repairs on infrastructure or equipment, often awarded to subcontractors through standing agreements or blanket contracts. For field service companies, IMR scopes provide a reliable stream of recurring work but typically require crews to mobilise quickly and hold multiple trade certifications to meet operator requirements.

A budgeting document used in oil and gas projects that outlines expected costs and seeks approval before work begins. Subcontractors often work under AFEs issued by operators.

A well stimulation service involving the high-pressure injection of fluids — such as fracturing fluid, cement, or acid — into a wellbore to improve production or complete the well; for subcontractors, it represents a specialised, equipment-intensive scope of work that typically requires certified operators, dedicated pump trucks, and close coordination with the primary operator on site.

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.