TOFD (Time-of-flight Diffraction)

Agreed reductions in oil production by member nations, typically OPEC (Organization of the Petroleum Exporting Countries) members, to stabilise prices. For subcontractors, these cuts often trigger project deferrals, reduced scope, and slower mobilisation schedules. Budget freezes from operators frequently follow, directly impacting field service award timelines.

The maximum depth reached by a drilling rig during well construction, measured from the surface to the bottom of the wellbore. For subcontractors, TD determines project scope, equipment requirements, and billing milestones as it marks the completion of the drilling phase.

A formal process where a client or prime contractor solicits bids from multiple subcontractors for a defined scope of work. Subcontractors submit priced proposals and are evaluated on cost, capability, and safety record. Winning a competitive tender typically requires balancing competitive pricing against maintaining viable margins.

A drilling schedule where wells are spaced consecutively with minimal downtime between completions. For subcontractors, it means sustained mobilisation of crews and equipment across multiple well sites. Expect extended contract durations but also compressed turnaround times between locations.

The slow, permanent deformation of metal components under sustained stress at elevated temperatures. Subcontractors must watch for creep in pressure vessels, piping, and structural welds during high-heat operations. Missed signs can lead to equipment failure, costly shutdowns, and liability exposure.

The date when equipment or a facility is officially commissioned and begins active operation. For subcontractors, this date often triggers billing milestones, warranty periods, or contract close-out requirements. Missing this date can result in penalties or delayed final payment.

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.