What is hydraulic fracturing?

Hydraulic fracturing, informally referred to as “fracking,” is an oil and gas well development process that typically involves injecting water, sand, and chemicals under high pressure into a bedrock formation via the well. This process is intended to create new fractures in the rock as well as increase the size, extent, and connectivity of existing fractures. Hydraulic fracturing is a well-stimulation technique used commonly in low-permeability rocks like tight sandstone, shale, and some coal beds to increase oil and/or gas flow to a well from petroleum-bearing rock formations. A similar technique is used to create improved permeability in underground geothermal reservoirs.

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Why have some estimates of undiscovered technically recoverable oil or gas changed so much from previous estimates?

Petroleum geologists have long known that oil and gas resources were present in “tight” or impermeable formations such as shale. But there was no way feasible way to extract that oil and gas, so they were not “technically recoverable” and were not be included in USGS assessment results. Thanks to new technologies, oil and gas can now be extracted...

Where in the United States is hydraulic fracturing being used for oil and gas extraction?

Hydraulic fracturing is used in many established oil and gas producing regions of the country as well as some areas new to the petroleum industry. Maps of major shale gas, tight gas, and tight oil basins are available from the U.S. Energy Information Administration, although not all of the shale basins shown currently have production.

Who is responsible for monitoring the issues associated with hydraulic fracturing and protecting our environment?

Individual states regulate many aspects of oil and gas exploration and production. Federal land managers, such as the Bureau of Land Management (BLM), the U.S. Forest Service (USFS), and the U.S. Fish and Wildlife Service (USFWS) have some oversight of oil and gas activities on the lands they manage. This includes conducting environmental impact...

When did hydraulic fracturing become such a popular approach to oil and gas production?

Hydraulic fracturing in vertical wells has been used for over fifty years to improve the flow of oil and gas from conventional reservoirs. However, the current practice of horizontal drilling coupled with multiple applications of hydraulic fracturing in a single well was pioneered in the late 1980s and has continued to evolve. Since the final...

What is in the fluid injected into the ground during hydraulic fracturing?

In general, hydraulic fracturing fluid is composed of water, proppant (typically sand), and chemicals. A public website known as FracFocus has been established by industry that lists specific materials used in many, but not all, hydraulically fractured wells. Individual companies select a few chemicals to be used from hundreds that are available...

What is the USGS role related to hydraulic fracturing?

The USGS is a science research agency with no regulatory, land management, or enforcement powers. This includes: research and assessments on the location, quantity, and quality of unconventional oil and gas resources whose production could involve hydraulic fracturing. Resource assessments estimate the quantity of oil and gas that is yet to be...

How much water does the typical hydraulically fractured well require?

There isn’t really a “typical” fractured well because the amount of water used depends on the rock formation, the operator, whether the well is vertical or horizontal, and the number of portions (or stages) of the well that are fractured. In addition, some water is recycled from fluids produced by the well, so the net consumption might be smaller...

What environmental issues are associated with hydraulic fracturing?

The actual practice of hydraulic fracturing (or “fracking”) is only a small part of the overall process of drilling, completing, and producing an oil and gas well. Environmental issues that are specifically related to hydraulic fracturing include: water availability spills of chemicals at the surface impacts of sand mining for use in the hydraulic...

How does hydraulic fracturing affect the surface or landscape of an area?

An area undergoing production of oil or gas using hydraulic fracturing technology shares many features with areas where conventional oil or gas is being developed, including: Roads Pipelines Compressor stations Processing facilities. Features that are unique to areas in which hydraulic fracturing is used include: Fewer but larger drilling pads,...

How does hydraulic fracturing differ from traditional petroleum development methods?

In a conventional oil or gas field, where the oil or gas is in relatively porous and permeable rock (i.e. the pores are connected), the oil or gas can usually flow naturally from the reservoir rock to the wellbore. Nonetheless, a variety of techniques are often used to improve the flow of oil or gas, including hydraulic fracturing. Rock formations...

Can hydraulic fracturing impact the quality of groundwater or surface water?

Conducted properly, hydraulic fracturing (or “fracking”) has little possibility of contaminating water supplies. Properly constructed wells prevent drilling fluids, hydraulic fracturing fluids, deep saline formation waters, or oil and gas from entering aquifers. Carefully constructed and operated well sites have the ability to contain potential...

How and where do drillers dispose of waste hydraulic fracturing fluid?

Most of the water and additives used in hydraulic fracturing (or “fracking”) remain deep underground in the geologic formation from which the oil or gas is being extracted. But some of the fluid, mixed with water or brine from the formation, returns through the well to the surface and is referred to as “produced water”. After a well is brought on-...
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Date published: May 27, 2015

Hydraulic Fracturing (Frac) Sand Sources and Production in the United States

Newly released research from the U.S. Geological Survey describes U.S. hydraulic fracturing (frac) sand deposits and their locations, and provides estimates of frac sand production, consumption, and reserves. A companion map of producing and potential frac sand and resin-coated sand source units in the conterminous U.S. is also included.

Date published: January 27, 2015

Historical Hydraulic Fracturing Trends and Data Unveiled in New USGS Publications

Two new U.S. Geological Survey publications that highlight historical hydraulic fracturing trends and data from 1947 to 2010 are now available.

Date published: June 20, 2012

USGS Releases Unconventional Gas Estimates for Five East Coast Basins

Using a geology-based assessment method, the U.S. Geological Survey estimated a mean undiscovered natural gas resource of 3.9 trillion cubic feet and a mean undiscovered natural gas liquids resource of 135 million barrels in continuous accumulations within five East Coast Mesozoic basins, according to a new USGS report.  

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Image: Perforating Gun for Hydraulic Fracturing
March 14, 2016

Perforating Gun for Hydraulic Fracturing

Unused and spent perforating gun used in oil and gas drilling and hydraulic fracturing. The pipe on the bottom left, shows holes created by the explosive charges mounted inside the pipe.

Image: Hydraulic Fracturing Well Heads
March 14, 2016

Hydraulic Fracturing Well Heads

Well heads hooked up in preparation for a hydraulic fracturing operation at a drill pad in the Fayetteville Shale gas play of Arkansas.

Image: Hydraulic Fracturing Operation Underway
March 14, 2016

Hydraulic Fracturing Operation Underway

A hydraulic fracturing operation is underway at this drilling pad in the Marcellus Shale gas play of southwestern Pennsylvania.

Image: Hydraulic Fracturing Drill Site
March 14, 2016

Hydraulic Fracturing Drill Site

A typical drill pad in the Marcellus Shale gas play of southwestern Pennsylvania.

Image shows sand in a hand
December 31, 2015

Frac Sands in Hand

Frac sands used in unconventional oil and gas development.

Image: Drilling Rig for Shale Gas Development
February 28, 2013

Drilling Rig for Shale Gas Development

A drilling rig for shale gas development take at night from an overlook on Route 6 in Bradford County Pennsylvania.