Fossil fuels have long been the world’s primary energy source and extracting those fuels from the ground has always involved inherently hazardous operations. Recently, the development of horizontal drilling technology has led to the increased use of hydraulic fracturing, better known as “fracking,” as a more affordable means for tapping into less-accessible oil and natural gas deposits. Like other extraction methods, fracking creates a broad variety of hazards for workers.
Hydraulic fracturing involves drilling into underground formations that contain oil and gas. The term derives its name from the injection of large volumes of fluid, chemicals, and proppants to fracture the formations and allow the oil and gas to pumped out. Proppants are materials used to keep the fractures open, such as crystalline silica sand or ceramic-based engineered materials.
Fracking can take place nearly anywhere deposits of oil and gas can be found, but it’s most common in rural and remote areas. All the work occurs outdoors, so workers are exposed to temperature extremes and other weather-related conditions. No two sites are alike, and the terrain and condition of soil can affect the safety of people and equipment.
A major concern on jobsites for fracking is the level of noise created by the equipment used to drill holes, pump the fracking fluid, and recover the oil and gas. Vehicles supplying the site create additional noise and hazards for workers. Careful planning for equipment locations, material storage and handling, traffic patterns, and shade and drinking water is critical.
Rig-up and rig-down hazards
The petroleum production industry refers to the delivery of production equipment, setup, and connection of “iron” (the common term for connections) as “rig-up” and the dismantling of drilling sites as “rig-down.” Because fracking sites are rarely permanent, rig-up and rig-down create ongoing hazards for workers.
Here again, planning and hazard assessments for locations of equipment, storage areas, loading/unloading, and traffic patterns are of critical importance. The ground where work takes place should be appropriately compacted and checked after significant weather events to ensure it remains stable. Fall protection is needed for any work areas more than four feet above ground level, which can include drilling rigs and truck beds during equipment loading and unloading. Work areas and walkways should provide protection from slippery surfaces, hoses, and other equipment.
Fracking typically requires the use of unique tools known as perforating guns, which are most often pipes with numerous perforations. Typically, shaped explosive charges are placed in the perforations. The perforating gun is lowered into the bore and the charges are detonated to fracture the surrounding rock.
Because perforating guns use explosives, workers need specialized training for handling, loading, and unloading the guns. When retrieving a gun from the bore, workers should assume that the gun may still contain live explosives and should inspect the gun to make sure all the explosives have detonated properly before moving or storing the gun.
Blending and injection
The fluid used to create pressure in fracking wells is normally a mix of water, proppants, and chemicals. Proppants are selected for their ability to be easily transported to the fractures and their resistance to the intense crushing pressures below the earth’s surface. Crystalline silica sand, the most common proppant, can expose workers to silica dust, which has been linked to silicosis, lung cancer, and other diseases.
Steps must be taken to limit workers’ exposure to silica dust (and any hazardous chemicals) as they handle the sand and blend the fracking fluid, and to protect workers from exposure to fluid during the high-pressure injection process. Workers must also receive training in how to respond to a chemical exposure or spill.
When wells encounter the extreme pressure underground, they may become channels for debris ranging from water, to rocks and mud, to gases such as methane and hydrogen sulfide, and volatile organic compounds. Piping should be designed to handle this pressure, with additional consideration given to connections and other areas more likely to fail. Sometimes, the gases in a flowback are highly flammable, so it’s critically important to keep potential ignition sources such as hot engine pipes, radios, and cellphones at a safe distance.