What is Oil and Gas Extraction?
Oil and gas extraction is a process that refers to the exploration and production of petroleum and natural gas from wells. Oil and gas extraction companies may operate oil and gas wells based on their own initiatives or act as a service provider on a contract or fee basis.
As classified under the North American Industry Classification System (NAICS) 211 of the United States Census Bureau, the oil and gas extraction subsector is part of the mining, quarrying, and oil and gas extraction sectors. The NAICS 211 classification states that industries under the oil and gas extraction subsector operate and/or develop oil and gas field properties. Such operation and development activities include:
- exploration for crude petroleum and natural gas;
- drilling, completing, and equipping wells;
- operating separators, emulsion breakers, desilting equipment, and field gathering lines for crude petroleum and natural gas; and
- other activities involved in the preparation of oil and gas up to the point of shipment from the producing property.
According to the US Environmental Protection Agency (EPA), the oil and gas extraction industry generates wastewater from the water extracted from the geological formations and from chemicals used during exploration, well drilling, and production of oil and gas. EPA promulgated the Effluent Guidelines and Standards for Oil and Gas Extraction, as stated in Part 435 of the Code of Federal Regulations (40 CFR Part 435). These regulations cover wastewater discharges from field exploration, drilling, production, well treatment, and well completion activities. Lastly, such guidelines are applicable to facilities that are organized into 5 subcategories: offshore, onshore, coastal, agricultural and wildlife water use, and stripper wells.
Oil and Gas Extraction Process
As per the Coloradans for Responsible Energy Development (CRED), the oil and natural gas extraction process involves 7 steps:
Step 1: Rig Site Preparation
To prepare for drilling, pads and access roads are built and traffic plans, noise barriers, and safety procedures are developed based on the relevant legislation.
Step 2: Drilling
The drill rig is transported to the location and then assembled. Afterward, the surface hole of the well is drilled down to 100 feet under the lowest aquifer and a steel casing is placed using cement. Upon reaching 1000 feet above from where the oil and natural gas is trapped, the surface hole is turned horizontal and out along the same rock bed.
Step 3: Cementing and Testing
The drill pipe should be taken out and the steel pipe pushed to the bottom upon reaching the target distance. Similar to the steel casing in Step 1, the well casing is also placed using cement. Before proceeding to the next step, ensure that thorough tests have been conducted to verify that the pipe is impermeable.
Step 4: Well Completion
A perforating gun is lowered into the ground and fired into the rock layer in the deepest part of the well to create holes that connect the rock holding the oil and natural gas and the wellhead. This step is crucial before drillers can tap the oil and natural gas.
Step 5: Fracking
Fracking fluid is pumped at high pressure through perforating holes to form cracks in the shale rock. Until the fracking of the wellbore’s lateral length is complete, repeat Step 4 and Step 5.
Step 6: Production and Fracking Fluid Recycling
After oil and natural gas flows up, the fracking fluid can be recovered and recycled.
Step 7: Well Abandonment and Land Restoration
While environmental conservation practices may vary per state, one example of a sensible oil and gas extraction process is seen in the state of Colorado. The Colorado law requires that the well must be permanently plugged and the land is returned to the way it was before the drilling operations started. Ultimately, the land can be used again for other purposes, leaving no sign that a well was once there.
This 7-step process aims to foster a practice of safe oil and gas extraction activities. Also, it’s recommended that a Spill Prevention, Control, and Countermeasure (SPCC) Plan is in place to prevent and mitigate the event of oil spills in navigable waters or shorelines.
OSHA Regulations on Oil and Gas Extraction Practices
The Occupational Safety and Health Administration (OSHA) lists the safety hazards and the other dangerous conditions that can result in fatalities for workers:
- Vehicle collisions
- Struck-by/caught-in/caught-between accidents
- Explosions and fires
- Falls
- Confined spaces
- Ergonomic hazards
- High-pressure lines and equipment
- Electrical and other hazardous energy
- Machine hazards
Further, the health hazards associated with oil and gas extraction activities include the following:
- Diesel Particulate Matter (DPM)
- Fatigue
- Hazardous chemicals
- Noise
- Silica
- Temperature extremes
- Hydrogen sulfide
- Hydrocarbon Gases and Vapors (HGVs) and low-oxygen environments
- Naturally Occurring Radioactive Material (NORM)
As per the US Bureau of Labor Statistics, about 386 fatal occupational injuries in the oil and gas extraction industry were recorded in 2016 to 2020. This data and the mentioned factors by OSHA are the main reasons why certain standards and regulations must be established and followed to keep workers safe and help employers determine and reduce the risks of hazard exposure in the workplace.
Thus, the General Duty Clause of the OSH Act requires employers to provide their employees with a safe workplace free from any recognized hazards that may lead to death or serious injury. Establishment and implementation of the guidelines and Standard Operating Procedures (SOPs) on the use of Personal Protective Equipment (PPE) are highly recommended.
Moreover, site preparation is the only aspect of oil and gas well drilling and servicing operations covered by OSHA’s Construction Standards (29 CFR 1926). Activities under this aspect include leveling the site, trenching, and excavation. Meanwhile, all other aspects of oil and gas well drilling and servicing operations are covered by OSHA’s General Industry Standards (29 CFR 1910). In cases when a serious hazard exists in the workplace that isn’t addressed by a certain OSHA standard, the General Duty Clause of the OSH Act applies by default.