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Industry Glossary Term

Kelly Bar

A heavy, telescoping steel rod that transmits rotary torque from a drill rig to the auger or cutting tool. Subcontractors operating foundation or piling rigs must inspect kelly bars regularly for wear and cracking. Damage affects drilling performance and can cause costly downtime on tight project schedules.

Related Terms

Alternative Delivery Models

Industry

Contracting arrangements beyond traditional lump-sum or day-rate structures, such as alliance, integrated project delivery, or performance-based contracts. These models shift how subcontractors are engaged, paid, and held accountable for outcomes. Understanding them helps field service firms assess risk, pricing strategy, and scope responsibilities before signing.

Reservoir Characterization

Industry

The process of mapping and analysing an underground reservoir's size, rock properties, and fluid content. Subcontractors use this data to understand scope for drilling, completions, and intervention work. It directly influences crew requirements, equipment specs, and contract duration.

Frac Campaign

Industry

A scheduled series of hydraulic fracturing operations across multiple wells or stages within a defined period, representing a concentrated burst of work that subcontractors must plan for with adequate crew, equipment, and supply chain capacity. For field service companies, winning a spot in a frac campaign can mean weeks of steady, high-volume work but also demands tight mobilisation timelines and the ability to scale up quickly.

Master Service Agreement (MSA)

Industry

A contract between an operator and a service company that establishes the general terms and conditions for all future work. Individual jobs are then executed under work orders or AFEs referencing the MSA.

BHA (Bottom Hole Assembly)

Industry

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.

Subsea Tieback

Industry

A pipeline or flow line system that connects a new offshore wellhead or satellite field back to an existing production facility or platform, allowing operators to develop remote reserves without building standalone infrastructure. For subcontractors, tiebacks often involve specialised subsea installation, inspection, and maintenance scopes that require certified divers, ROV crews, or subsea engineering support.

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