DEF (Diesel Exhaust Fluid)

The segment of the oil and gas industry involved in exploration and production (E&P). Includes drilling, completions, and well operations.

A structural anchor or connection point used to secure equipment, pipelines, or wellheads back to an existing infrastructure system, commonly referenced in subcontractor scopes of work when connecting new installations to live or existing lines. Subcontractors should confirm tieback specifications and isolation procedures clearly in their contracts, as this work often involves elevated risk and may require additional certifications or permits.

A floating offshore structure anchored by a deep vertical cylinder, used in deepwater oil and gas production. Subcontractors access it by crew boat or helicopter for maintenance, inspection, and equipment services. Mobilisation costs and offshore scheduling are key considerations when bidding work on spars.

The volume of crude oil a refinery processes over a set period, typically measured in barrels per day. Higher throughput means more maintenance, turnaround, and inspection work for subcontractors. Expect busier scopes and tighter schedules when a client ramps up processing capacity.

The construction and assembly of the above-water structures on offshore platforms, including decks, modules, and processing equipment, where subcontractors are typically engaged for specialised trades such as structural welding, pipefitting, electrical, and instrumentation work. For field service companies, topside scopes often involve strict offshore safety certifications, remote logistics, and milestone-based billing tied to fabrication progress.

The prime contractor hired by an owner to manage a project, responsible for awarding and overseeing subcontracts. As a sub, your contract, invoicing, and site access typically flow through the GC. They control your payment terms and schedule, making them your primary business relationship on site.

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