The oil and gas life cycle and its hazards

Oil and gas sites are among the most varied and most dangerous workplaces in either country. On a single day a worker might drive two hours on a gravel lease road, check pressures at a wellhead, gauge a tank of produced fluid, help a crew rig up a service unit and then wait in a truck while a pipeline is blown down. Each of those tasks carries a different mix of hazards: moving vehicles, high pressure, flammable and toxic gas, heavy rotating equipment, falls, cold and isolation. This course is the entry point to the oil and gas sites track. It gives workers, new supervisors, contractors and visitors the orientation they need to recognize those hazards, follow site rules and respond when something goes wrong.

HSE-103 introduced hazard recognition and risk assessment, and HSE-310 and HSE-311 covered industrial plants and process safety. This course applies those ideas to upstream sites (exploration, drilling, completion and production) and midstream sites (gathering, processing, compression and transmission). Three more courses in the track go deeper: HSE-331 covers drilling and well site hazards, HSE-332 covers facilities and pipelines, and HSE-333 covers permits to work and isolation in oil and gas. Where a topic belongs to one of them, this course introduces it and points ahead.

Why orientation matters here

Oil and gas work combines several features that make orientation unusually important. Sites are spread over large areas, often far from towns and medical help. Many workers move between sites and employers every week, so they meet new layouts, new equipment and new rules constantly. Most sites have several employers working side by side: the operator who holds the license or permit, a drilling or service contractor, specialist subcontractors, truck drivers and visitors. And the materials themselves, hydrocarbons under pressure, sometimes containing hydrogen sulfide, can injure many people at once if they escape.

An orientation is how a site closes the gap between general training and the specific hazards of that place on that day. It tells a newcomer where the hazards are, which rules apply, where to muster, who is in charge and how to raise a concern. Industry has standardized much of this. In Canada, Energy Safety Canada's Common Safety Orientation gives workers a common base of safety knowledge across the industry, and in the United States, basic orientation programs such as SafeLandUSA play a similar role. Lesson 3 explains how these industry programs fit with the site-specific orientation every site must still give.

From exploration to reclamation

The oil and gas life cycle runs from finding a resource to restoring the land after production ends. Each phase has its own sites, equipment, workforce and hazards. Knowing where a site sits in the life cycle is the first step in knowing what can hurt you there.

Workers often describe the industry in three parts. Upstream is exploration, drilling, completion and production. Midstream is gathering, processing, compression, transmission by pipeline and storage. Downstream is refining, petrochemicals and retail fuel. This track covers upstream and midstream sites; refineries and chemical plants are closer to the industrial track (HSE-310 to HSE-313), and retail fuel stations have their own course, HSE-350.

Conventional, unconventional and oil sands

The kind of resource changes the work. Conventional reservoirs are porous rock where oil or gas flows to a vertical well with little help. Unconventional resources, such as shale and tight formations, need long horizontal wells and hydraulic fracturing to produce. A typical modern pad in the Montney formation of Alberta and British Columbia or the Bakken of North Dakota holds several horizontal wells drilled from one surface location, with a production facility on or near the pad. Fracturing operations bring large crews, many trucks, high-pressure pumping equipment and huge volumes of sand and water to the site for a few weeks, after which the site settles into a quieter production phase with occasional visits.

Oil sands, found in northeastern Alberta, are produced in two ways. Surface mining digs out bitumen-bearing sand near the surface and processes it in large plants, so the hazards resemble those of large mines and heavy industry. In-situ operations, such as steam-assisted gravity drainage, inject steam through paired horizontal wells and bring heated bitumen to the surface, so they combine well site, high-temperature steam and process plant hazards. Offshore operations, off Newfoundland and Labrador and Nova Scotia and in the US Gulf of Mexico, add helicopter transport, marine hazards and living on an installation. They have separate regulators and specialized training, and this course mentions them only briefly.

Where workers are hurt and killed

Data from the United States show clearly where the serious risk lies. The National Institute for Occupational Safety and Health (NIOSH) maintains a database called Fatalities in Oil and Gas Extraction (FOG) that collects detailed information on worker deaths. Its report covering 2014 to 2019, published in 2023, counted 470 fatalities, of which 401 were traumatic injuries and 69 were cardiac deaths at work. Vehicle incidents were the most common type of fatal event, followed by contact injuries (being struck by, caught in or crushed by objects and equipment) and then explosions and fires. The program below works through the published percentages.

# Shares of 470 oil and gas extraction fatalities, 2014 to 2019,
# from the NIOSH FOG surveillance report (percentages as published).
total = 470
shares = [
    ("Vehicle incidents", 26.8),
    ("Contact injuries", 21.7),
    ("Explosions", 14.5),
    ("Fires", 12.8),
    ("Falls", 4.9),
    ("Harmful substance exposures", 3.4),
]
listed = 0
for name, pct in shares:
    n = round(total * pct / 100)
    listed += n
    bar = "#" * round(pct)
    print(f"{name:28} {pct:5.1f}%  about {n:3d}  {bar}")
print(f"{'Other events (incl. cardiac)':28} {100 - sum(p for _, p in shares):5.1f}%  about {total - listed:3d}")
print(f"Explosions and fires together: {14.5 + 12.8:.1f}% of deaths")

Vehicle incidents             26.8%  about 126  ###########################
Contact injuries              21.7%  about 102  ######################
Explosions                    14.5%  about  68  ##############
Fires                         12.8%  about  60  #############
Falls                          4.9%  about  23  #####
Harmful substance exposures    3.4%  about  16  ###
Other events (incl. cardiac)  15.9%  about  75
Explosions and fires together: 27.3% of deaths

Several patterns stand out. More than a quarter of deaths happened on the road or in vehicles, far from the wellhead. Contact injuries, mostly involving heavy equipment, pipe and rotating machinery, were the next largest group. Explosions and fires together accounted for roughly as many deaths as vehicles. The same report found that about 60 percent of the deaths were workers of well servicing companies, and fewer than 20 percent were employees of drilling contractors; employees of the operating companies themselves were a small share. In other words, the people most at risk are usually contractors doing hands-on work. The US Bureau of Labor Statistics counted 65 fatal work injuries in oil and gas extraction and its support activities in 2024. Activity remains high: according to the Energy Information Administration, US crude oil production averaged a record of about 13.6 million barrels per day in 2025, with roughly half coming from the Permian Basin of Texas and New Mexico.

Comparable national data for Canada are spread across provincial workers' compensation boards and regulators, but the pattern is similar: motor vehicle incidents, struck-by and caught-between injuries, falls, and fires and explosions dominate serious incidents in the upstream industry. Lesson 2 maps the regulators who collect and publish that information.

Thinking in energy

A useful way to scan any site is to ask what forms of energy could be released and reach a person. Energy Safety Canada's Common Safety Orientation teaches hazard recognition with an energy wheel, and many US companies use similar tools. The energy forms are gravity, motion, mechanical, electrical, pressure, temperature, chemical, biological, radiation and sound. An oil and gas site usually has all ten at once: a tank top (gravity), a haul truck (motion), a pump jack (mechanical), a motor control panel (electrical), a pressurized separator (pressure), a line heater (temperature), crude oil and sour gas (chemical), insects and wildlife (biological), naturally occurring radioactive material in old scale (radiation) and a compressor (sound).

Energy thinking connects directly to the most serious outcomes. Incidents that kill or permanently injure people almost always involve a large, uncontrolled release of energy: a vehicle at highway speed, a pressurized line that parts, a heavy load that falls, a gas cloud that ignites. Many companies and industry associations have adopted short lists of life-saving rules aimed at these high-energy hazards, such as rules on bypassing safety controls, confined space entry, driving, energy isolation, hot work, line of fire, safe mechanical lifting, work authorization and working at height. The updated Common Safety Orientation released in October 2025 teaches the energy wheel alongside ten life-saving rules. Learn the rules your site uses; they mark the places where a single mistake is most likely to be fatal.

The Pinecrest pad: our running example

Throughout this course, examples use an invented site: the Pinecrest pad and battery, operated by an invented company, Larchwood Resources, about 40 miles (64 km) south of Watford City, North Dakota. The pad holds eight horizontal wells producing oil and associated gas from the Bakken formation. The associated gas contains about 0.5 percent hydrogen sulfide (5,000 ppm) in the raw stream. A small tank battery beside the pad has an inlet separator, a heater-treater, a compressor, four 400 bbl (64 m³) production tanks for oil and water, a flare stack and a pipeline riser where the gathering line leaves the site. A gravel lease road joins a state highway 9 miles (14 km) away. Contractors visit for well servicing, trucking, maintenance and pipeline work. All figures, people and incidents at Pinecrest are invented for teaching.