Hydraulic fracturing is a technique used to harvest natural gas in shale deposits found thousands of feet below the surface. The practice is known as “fracking.” It’s generally permitted in most states, however, some have banned or placed moratoriums on fracking due to ongoing environmental concerns.
Over the last two decades, fracking has contributed substantially to the oil and gas industry. This is partially attributed to advances in fracking technique, namely slickwater and horizontal drilling. Because fracking remains somewhat controversial, it’s imperative that licensed engineers understand the process and its implications.
This article provides an overview of hydraulic fracturing, environmental considerations, and the role of professional engineers (PE).
What is Hydraulic Fracturing?
Hydraulic fracturing is a well stimulation technique that creates cracks, or fractures, in shale and other “tight” rocks—impermeable rock formations that lock in fossil fuels. Fractures are created using high-pressure injections of fracturing fluids, a mix of water, sand, and chemicals formulated to break open the rock and hold it open while collecting natural gas.
Interestingly, fracking is not new. It was discovered by an accidental observation made by Colonel Edward A.L. Roberts at the Battle of Fredericksburg during the Civil War. Colonel Roberts observed the impact made by artillery in narrow, water-filled channels. After the war, he designed an “exploding torpedo” that was lowered into oil wells and detonated.
Water was pumped into the shattered rock, which caused oil flows to increase by as much as 1200%! Eventually, explosives were replaced by high-pressure blasts of liquids, giving the technique its name, hydraulic fracking.
In the early part of this century, slickwater was created, which is a mixture of water, sand, and chemicals that make the fluid less viscous. Another big break in fracking came from horizontal drilling, which increases the production of each well and reduces the number of drilling holes required to access the oil reserves.
The Professional Engineer’s Role in Hydraulic Fracturing
Oil exploration in general requires a lot of input. Hydraulic fracturing is no different. Mechanical engineers are hired to assist with the machinery used to drill and extract gas from shale deposits. Civil engineers assess foundation structures, water retention ponds, egress and ingress for heavy machinery and loaded tanker trucks. PEs are involved in designing, executing, and monitoring the fracking process to optimize oil and gas extraction.
Here are just a few considerations requiring the expertise of Professional Engineers:
- Geotechnical and Geological Factors: Geotechnical engineers understand subsurface conditions, including fault lines, bedding planes, and soil stability, which are crucial for predicting fracture behavior and ensuring safe operations. Engineers must evaluate how geological features influence fracture paths and containment.
- Rock Formations and Reservoir Characteristics: The type, porosity, and permeability of rock formations directly affect how fluids flow and fractures split. Reservoir modeling helps engineers optimize fracturing strategies for maximum oil and gas extraction.
- Stress Analysis and Fracture Propagation: Stress analysis is essential to predict the direction and extent of fracture growth to ensure fractures reach target zones without compromising nearby environmental formations, structures, or infrastructure.
- Fluid Dynamics and Chemical Engineering: Chemical engineers apply fluid dynamics to optimize the transport of fracturing fluids through complex wellbores and rock layers to enhance fracture efficiency and minimize environmental impact.
- Composition of Fracturing Fluids and Proppants: Fracturing fluids typically include water, sand (proppants), and chemical additives to reduce friction, prevent microbial growth, and carry proppants deep into fractures. The right combination improves fracture stability and hydrocarbon flow.
- Flow Mechanics and Pressure Control: Fluid flow rates and pressure are critical to initiate and maintain fractures without damaging the well or surrounding structures. Engineers use pressure modeling to ensure safe and effective fracturing.
- Structural and Mechanical Engineering: Mechanical integrity of the well and surrounding infrastructure under high-pressure conditions needs to be carefully designed. Structural engineers assess loads and stresses to prevent equipment failure and ensure long-term stability.
- Well Integrity and Casing Design: Well casing design protects groundwater and ensures zonal isolation during and after fracturing. Engineers select materials and layering techniques to withstand high pressures and corrosive environments.
- Equipment and Infrastructure Considerations: Hydraulic fracturing requires high-pressure pumps, blending units, storage tanks, and transport logistics that need to function seamlessly. Engineers evaluate site-specific needs to design infrastructure that supports safe, efficient operations.
Environmental and Regulatory Considerations
Hydraulic fracturing is regulated by state and federal law. Under federal regulations, fracking operations must comply with the Clean Water Act, Clean Air Act, Safe Drinking Water Act, Resources Conservation and Recovery Act, and Comprehensive Environmental Response, Compensation, and Liability Act.
In addition, any fracking taking place on Bureau of Land Management (BLM) lands needs to comply with permitting and environmental protections. On July 15, 2015, the BLM issued its final hydraulic fracturing rule to establish consistent requirements designed to prevent problems before they occur and safeguard the environment.
Lastly, most states have their own laws regarding fracking. States are often also responsible for promulgating federal regulations, such as the Clean Water Act. Fracking poses seismic activity risk. However, not from the process itself, but from the disposal of wastewater generated during the process.
Wastewater is injected into deep wells, which can apply pressure to existing fault lines, potentially leading to earthquakes. This becomes a concern for many states with known earthquake risk.
Other considerations with hydraulic fracturing include water usage and management and groundwater contamination risk. Water management includes water intake and disposal. Most wastewater is managed through storage, treatment, or deep-well injection. Fracking operations also reuse wastewater.
While groundwater contamination is one of the biggest concerns in hydraulic fracturing. Other environmental concerns include using up water resources, especially in desert or arid parts of the U.S., and ecosystem changes. Extracting so much water to use in fracking operations can impact freshwater ecosystems and aquatic life.
Continuing Education and Professional Development
Oil and gas exploration is big business. According to the Bureau of Labor Statistics, petroleum engineers earn a median annual salary of $163,170 compared to civil engineers who earn a median annual salary of $101,160. The requirements to become a petroleum engineer are the same as other engineering specialties—earn a four-year engineering degree, become licensed, and gain work experience and certifications in petroleum engineering. Petroleum engineers work in drilling, production, reservoir design, and other specialties within the niche.
If this is a field that interests you, consider McKissock’s continuing education course in Hydraulic Fracturing. The course explores hydraulic fracturing in the United States and provides an overview of hydraulic fracturing, its benefits, drawbacks, and impacts on people and the environment. Additionally, you will learn about geological formations, porosity, shale, and permeability.
Connect with McKissock today to learn about all of our online Professional Engineering continuing education courses!
