Drilling Spread

A company that provides specialized services to oil and gas operators, such as drilling, completions, workover, transportation, or maintenance. Also called oilfield services (OFS).

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 that is drilled vertically to a certain depth then curved to run horizontally through a target formation, requiring subcontractors to mobilise specialised equipment and crews for extended-reach drilling, completions, and stimulation work that typically involves more complex logistics and longer on-site durations than conventional vertical wells.

The collection of drilling tools and equipment at the bottom of the drill string, including the drill bit, drill collars, stabilizers, and downhole motors. For drilling subcontractors, BHA configuration directly impacts drilling performance, tool wear rates, and operational efficiency.

An unmanned, tethered underwater robot used to inspect, survey, or perform work on subsea pipelines, wellheads, and structures — subcontractors providing ROV services typically require specialised operators and vessels, and should account for mobilisation costs and standby rates when bidding these scopes.

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.