Contractors, prime contractors and multi-employer sites

Few oil and gas sites are worked by a single employer. A typical pad during completion might have the operator's wellsite supervisor, a fracturing company, a wireline contractor, a coiled tubing unit, water transfer and trucking companies, rental equipment providers, a flowback crew, a security service and a steady stream of delivery drivers, each with its own supervisors and procedures. The NIOSH data in Lesson 1 showed that most fatalities were among contractors, especially well servicing workers. When work is split among many employers, hazards fall into the gaps between them: one crew's work endangers another, nobody is sure who is in charge, and everyone assumes someone else has checked. This lesson explains how the law assigns responsibility on multi-employer sites, how operators manage contractors and how workers can keep themselves safe in a crowded workplace.

HSE-221 Lesson 9 covered simultaneous operations and interfaces under permit systems, and HSE-230 covers field-level hazard assessment. HSE-406, Contractor Safety Management, will cover the management system side for safety professionals in depth. This lesson gives the orientation-level view that every worker and new supervisor on an oil and gas site needs.

Who is on site

It helps to know the roles you will meet:

• The licensee or operator: the company that holds the energy regulator's licence and controls the site. Its representative on location is often called the wellsite supervisor, consultant or company representative.
• The prime contractor: the party designated to coordinate health and safety for the whole site when two or more employers are present.
• Contractors: drilling, completion, servicing, construction, maintenance and trucking companies, each the employer of its own workers.
• Subcontractors and owner-operators: companies and self-employed people hired by contractors, often for short tasks.
• Suppliers and service providers: rental equipment companies, chemical suppliers and technicians who deliver and set up equipment.
• Visitors and regulators: landowners, inspectors, engineers and others who need orientation and escort.

How the law assigns responsibility

In Alberta, the Occupational Health and Safety Act requires a prime contractor on every oil and gas work site, and every construction site, where two or more employers or self-employed persons are working. The person in control of the work site, usually the licensee, must designate the prime contractor in writing and post its name where it can be seen; if nobody is designated, the person in control is treated as the prime contractor. The prime contractor must establish a system that ensures compliance with the law and cooperation between employers and workers, designate a person to oversee that cooperation and the health and safety committee duties for the site, inform everyone on site of known hazards and keep its own work free of uncontrolled hazards. Each employer, contractor and supplier keeps its own duties as well. British Columbia's Workers Compensation Act has a similar prime contractor requirement for multiple-employer workplaces, with the owner acting as prime contractor unless it designates someone else in writing, and Saskatchewan's law also places coordination duties on contractors and owners at multi-employer worksites.

Managing contractors: the life cycle

Good operators manage contractors through a life cycle rather than relying on a contract clause. Before work, they prequalify contractors by reviewing their safety program, training records, injury statistics and certifications such as a Certificate of Recognition (COR), which Energy Safety Canada administers for the oil and gas industry in Alberta; many use third-party prequalification services. They then plan each job with the contractor, agree how hazards at the interfaces will be controlled and confirm that workers have the required training. During the work, they orient contractor workers, hold coordination meetings, monitor performance and stop work when needed. After the work, they evaluate the contractor's performance and feed the results into future selection.

A key planning tool is the bridging document, which links the operator's safety management system with each contractor's. It records whose procedures apply to which activities (for example, the operator's permit system, the contractor's lifting procedures), who is responsible for gas monitoring, emergency response and incident reporting, and how differences between the two systems will be resolved. Without a bridging document, two crews on the same site may follow different rules for the same hazard.

New and short-service workers

Workers new to the industry, to a company or to a type of job are injured at higher rates than experienced workers. Many operators and contractors run short-service employee programs: new workers wear a distinctive hard hat colour or sticker for their first months, are assigned a mentor, are limited to a set number per crew and are not allowed to do certain high-risk tasks alone. If you are new, ask questions and say when you have not done a task before; if you are experienced, watch out for new crew members, explain why things are done and stop them before they step into a hazard.

Coordinating on the day

On a busy site, coordination happens through a few routine tools:

• A daily coordination or pre-job meeting where all crews share their plans for the day, identify conflicts and agree on controls.
• Field-level hazard assessments or job safety analyses for each task, reviewed when conditions change (HSE-230).
• A permit system that controls hazardous work and shows who is working where (HSE-221 and HSE-333).
• A simultaneous operations (SIMOPS) plan when different operations, such as production and completion or crane lifts and hot work, happen close together.
• Shift handovers that pass on the state of work, permits and isolations.
• Stop work authority, which allows any worker to stop a task they believe is unsafe, without fear of reprisal.

Stop work authority deserves emphasis. It only works if people use it and supervisors back it. On a multi-employer site, a worker from one company may see a hazard created by another company's crew. Stopping the work and raising the concern is the right thing to do, and most operators make clear that stop work authority extends across company lines. The right to refuse unsafe work under OHS law, explained in HSE-101, protects workers who refuse work they believe endangers them.

Visitors and escorts

Visitors such as engineers, sales representatives, landowners, auditors and new managers often know little about oil and gas hazards. Most sites require every visitor to sign in, receive at least a short orientation covering alarms, muster points, wind direction and restricted areas, wear the required PPE and a gas monitor where H2S may be present, and stay with a trained escort. The escort is responsible for keeping the visitor out of red zones and hazardous areas and for leading them to safety in an emergency. Inspectors from regulators also sign in and receive orientation, although they have legal powers to enter and examine the site.

Incidents on multi-employer sites

When something goes wrong on a site with many employers, reporting and investigation must not fall into the gaps. Every injury, near miss and dangerous occurrence should be reported to the worker's own supervisor and to the coordinating party for the site, whatever company the worker belongs to. Legal reports to the OHS regulator are usually the duty of the injured worker's employer, and some events must also be reported by the operator to the energy regulator. Investigations work best when they involve all the employers whose work contributed, so that each can fix its part, and when lessons are shared across crews and companies rather than kept within one. A contractor that hides incidents to protect its standing with the operator puts everyone on the site at risk; operators that punish contractors for honest reporting encourage exactly that.

Communication is a recurring cause of multi-employer incidents. Crews may use different radio channels, different terms for the same equipment and, sometimes, different working languages. Sites reduce the risk by agreeing a common radio channel for emergencies, using plain language rather than company jargon in coordination meetings, confirming instructions by repeating them back and making sure every worker can understand alarms and emergency instructions.

Measuring contractor safety

Operators compare contractors using injury statistics. The total recordable injury frequency (TRIF) counts injuries that need medical treatment beyond first aid, lost time or restricted work, per 200,000 hours worked, which is roughly 100 workers working for a year. Lost-time injury frequency counts only injuries that cause time away from work. Statistics from small contractors swing widely from year to year, so operators look at trends and at leading indicators such as training completion, inspections and near-miss reporting as well. The program below calculates these rates for three invented contractors bidding for work at Pinecrest.

# Invented contractor data: name, hours worked, recordable injuries, lost-time injuries, COR held
bids = [("Contractor A", 410_000, 3, 1, True),
        ("Contractor B", 95_000, 2, 1, True),
        ("Contractor C", 260_000, 1, 0, False)]
for name, hours, rec, lti, cor in bids:
    trif = rec * 200_000 / hours
    ltif = lti * 200_000 / hours
    flags = [] if cor else ["no COR: review program before award"]
    if hours < 200_000:
        flags.append("small sample: look at 3-year trend")
    print(f"{name}: TRIF {trif:4.2f}, LTIF {ltif:4.2f}", "; ".join(flags))

Contractor A: TRIF 1.46, LTIF 0.49 
Contractor B: TRIF 4.21, LTIF 2.11 small sample: look at 3-year trend
Contractor C: TRIF 0.77, LTIF 0.00 no COR: review program before award

No single number decides a contract. Contractor B's rates look worst, but its small number of hours means one or two injuries swing the rate widely, so its three-year trend and program matter more. Contractor C has the best rate this year but raises a different question that needs a closer look at its program. Numbers start a conversation about how each contractor manages its hazards; they do not end it.