The video above is from the March 2013 iPad edition of National Geographic magazine.
 
Hydraulic fracturing, or fracking, is a drilling method used to extract petroleum (oil) or natural gas from deep in the Earth. In the fracking process, cracks in and below the Earth's surface are opened and widened by injecting water, chemicals, and sand at high pressure. 
 
Some resources extracted through fracking are called “tight oil” or “tight gas,” because these pockets of fossil fuels are tightly trapped in hard shale rock formations. By accessing tight oil and tight gas, the sophisticated technologies used in fracking are rapidly expanding petroleum and natural gas production in the United States. 
 
This video explains the technology of fracking using the example of the Iverson oil well, which drills into the Bakken shale formation near Williston, North Dakota. 
  • A handful of other nations are investing in hydraulic fracturing to extract petroleum and natural gas. 
    • Fracking is used to extract natural gas from the Montney shale formation in Alberta and British Columbia, Canada.
    • Fracking is used to extract natural gas from the Sichuan basin in China.
    • Fracking is used to extract petroleum from the Taranaki shale formation in New Zealand.
  • One of the most active sites of fracking for oil is the Bakken shale formation, stretching from western North Dakota and Montana through the southern part of the Canadian province of Saskatchewan.
  • Fracking is used to extract natural gas from the Marcellus shale formation in the northern Appalachian Basin, extending through the states of New York, Pennsylvania, Ohio, Maryland, West Virginia, and Virginia.
  • One of the first places hydraulic fracturing technology was used was the Barnett shale formation in northern Texas. 
extract
Verb

to pull out.

fossil fuel
Noun

coal, oil, or natural gas. Fossil fuels formed from the remains of ancient plants and animals.

fracking
Noun

process usually used to extract oil and natural gas in which fractures in the Earth's surface are opened and widened by injecting water, chemicals, and sand at high pressure. Also called hydraulic fracturing.

Noun

type of fossil fuel made up mostly of the gas methane.

Noun

fossil fuel formed from the remains of ancient organisms. Also called crude oil.

shale
Noun

type of sedimentary rock.

sophisticated
Adjective

knowledgeable or complex.

technology
Noun

the science of using tools and complex machines to make human life easier or more profitable.

tight gas
Noun

unconventional gas trapped in impermeable rock formations.

tight oil
Noun

petroleum trapped in often-impermeable rock formations.