Hydraulic Fracturing Frequently Asked Questions
- What is hydraulic fracturing?
- Hydraulic fracturing, or frac’ing as it’s often called, is a technology used to stimulate the flow of hydrocarbons from new and existing oil and gas wells. It creates millimeter-thick fissures in the rock formation, providing a conductive path for hydrocarbons to flow into the wellbore. These new paths increase the rate that fluids can be produced from the reservoir formations, in some cases by many hundreds of percent.
- Is hydraulic fracturing a new technology?
- Over the past 60 years, hydraulic fracturing has been used for a wide variety of purposes, from stimulating the flow of water from water wells, to bringing geothermal wells into commercial viability. Frac’ing has been used in about one million wells during the past six decades in shale formations, such as the Marcellus Shale which is believed to be one of the world’s largest natural gas-bearing formations.
- How does the fracturing process work?
- Operators will drill a well in low permeability rock, such as shale. Then, to increase permeability to release hydrocarbons, the well is stimulated with high pressure fluids. In order to keep fractures from closing up, proppant comprised typically sand, is pumped into the fractured rock. Finally, the well begins to flow oil and gas until the fractured area is depleted.
- Why is hydraulic fracturing necessary?
- Without the recent and significant technological advancements made in horizontal drilling and in hydraulic fracturing, the oil and natural gas found in deep shale formations would be uneconomic and unrecoverable. The creation of small cracks, or fractures, in the shale allows the hydrocarbons trapped within the very dense rock formation to flow through the wellbore so that it can be collected at the surface.
- Does hydraulic fracturing cause earthquakes?
- The earth is naturally under tectonic stress and earthquakes happen all the time as a result of continental drift. Typically around the world there are more than 20 earthquakes with a magnitude greater than 2.5 every day and countless more at smaller magnitudes. Seismic events created by frac’ing are usually 10,000 times smaller in magnitude and therefore, are not typically felt at the earth’s surface. Rarely, the fluids from frac’ing may find their way into a pre-existing fault or fracture in the earth that is under stress, waiting to move. The fluids may “lubricate” the fault allowing it to release its pent up stress earlier than it would naturally, and most likely at a lower magnitude of event.
- What chemicals are used in frac’ing?
- Approximately 99.5% of the volume of materials used during the frac’ing of deep shale gas wells consists of water and sand. Other typical ingredients include a friction reducer, gelling agent and antibacterial agents.
- Are frac’ing chemicals dangerous?
- Frac’ing chemicals are no more dangerous than any industrial or household chemicals when used properly. However, they do require safe work practices, proper site preparation and attentive handling to ensure the safe management of chemicals, as well as the protection of the public, well site employees, contractors and the environment. Each chemical used during the frac’ing process has a Material Safety Data Sheet (MSDS), which is readily available at a central location for all personnel on the job site. The MSDS outlines the hazards associated with well site chemicals and the appropriate steps to protect the user and the environment. It is important to note that in deep natural gas shale drilling operations the targeted frac’ing zones are, on average, located an estimated 6,000 to 12,000 feet below the freshwater zones, and are separated by millions of tons of impermeable and nonporous rock formations thus making the potential for migration into freshwater zones a near scientific impossibility.
The website fracfocus.org has been formed by the industry to enable voluntary disclosure of fracturing fluids and material used by operators in their wells in the United States. Thousands of wells are now included in this database for access by the public.
- Why is there methane in well water in hydraulic fracturing areas?
- Methane is a natural hydrocarbon gas that is flammable and explosive in certain concentrations. It is produced either by bacteria or by geologic processes involving heat and pressure. Biogenic methane is created by the decomposition of organic material through fermentation, as is commonly seen in wetlands, or by the chemical reduction of carbon dioxide. It is found in some shallow, water-bearing geologic formations, into which water wells are sometimes completed. Thermogenic methane is created by the thermal decomposition of buried organic material. It is found in rocks buried deeper within the earth and is produced by drilling an oil and gas well and hydraulically fracturing the rocks that contain the gas.
- What constitutes contamination?
- The existence of fracturing-related fluids in a drinking water supply, found to reside there in sufficient quantities pursuant to activities directly related to hydraulic fracturing. No documented case of drinking water contamination has been credibly tied to hydraulic fracturing in the past 60 years.*
- How is hydraulic fracturing regulated?
- Before a well can be drilled, it must be approved by state officials and a permit-to-drill. Once approved, every step of the process is conducted in accordance with state requirements.
- Was hydraulic fracturing able to secure an exemption to regulation under the Safe Drinking Water Act?
- Frac’ing was never regulated under the Safe Drinking Water Act, therefore, it could never have been granted exemption. In 1974, the act was passed but never considered hydraulic fracturing to be included at the time. After three amendments to the act in 1980, 1986 and 1996, at no point was hydraulic fracturing considered for regulation under the Safe Water Drinking Act.
- Are states equipped with the expertise that’s needed to safely regulate the hydraulic fracturing process?
- Each state with hydraulic fracture operations has a team of highly qualified inspectors and scientists who oversee and guarantee execution of oil and natural gas extraction.
Well operators must work with state regulators, and comply with federal regulations. OSHA, Environmental Response, Compensation and Liability Act and the Toxic Substances Control Act all contain record keeping and reporting rules followed by energy producers. These regulations ensure all chemicals used in the extraction process are properly handled and stored, and that works and first responders are made aware of the substances they handle.*
*Provided by EnergyinDepth.org