How does shale fracking work?
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.
What is Devonian shale?
Black shales of Devonian age in the Appalachian basin are a unique rock sequence. The high content of organic matter, which imparts the characteristic lithology, has for years attracted considerable interest in the shales as a possible source of energy.
How is shale gas produced by fracking?
For shale gas, hydraulic fracturing of a reservoir is the preferred stimulation method (see graphic below). This typically involves injecting pressurized fluids to stimulate or fracture shale formations and release the natural gas. Sand pumped in with the fluids (often water) helps to keep the fractures open.
How did the Devonian Chattanooga shale form?
I suggest that the Chattanooga Shale, as found in Tennessee, originated as a volcaniclastic deposit which mixed with organic debris. Conant and Swanson (1957, p. 19) identify the organic constituents as marine algae and coalified driftwood of a species known to exist in Devonian time.
How long does it take to drill a fracking well?
Fracking takes about two to three days in what is roughly a 10- to 14-day process of drilling and completing a well.”Fracking is one of the important parts of this,” said Leen Weijers, vice president of technology and sales for Liberty Oil Field Services, a private contractor that fracs wells for oil and gas …
How far horizontally does fracking go?
Horizontal drilling can extend more than 1 mile (1.6 km) from the vertical well bore, according to Texas A&M University’s publication “Hydraulic Fracturing and your Private Water Well.”
What makes the Chattanooga Shale so black?
Extremely fine-grained quartz is the major constituent of the black shale beds of the Chattanooga and probably makes up about 20 to 25 percent of the rock.
Why is the Chattanooga Shale black in color?
The most conspicuous lithologic feature of the organic-rich Devonian shales is the dark color, the principal cause of which is the organic carbon content of the shale. To a lesser extent, and in part dependent on the organic carbon content, iron in the reduced state can contribute to the dark color (Potter et al.
How long will fracking oil last?
Fracking is a temporary process that occurs after a well has been drilled and usually takes only about 3-5 days per well. Sometimes, wells are re-fracked to extend their production, but the energy each well can produce may last for 20 to 40 years.
How do you get oil out of shale?
Ex SituDuring the ex situ process, oil shale is first extracted from the earth by surface or underground mining. The rock is crushed, and then retorted (heated) to release the shale oil. The shale oil is then refined of impurities, such as sulfur. In Situ In situ is a new, experimental method of extracting shale oil.
How deep do they drill when fracking?
In simplified terms, the fracking process starts with a well that is drilled vertically or at an angle from the surface to a depth of 1 to 2 miles (1.6 to 3.2 kilometers) or more, according to the U.S. Environmental Protection Agency (EPA).
How far down do they drill for fracking?
“The drilling comes first and then the fracking.” Wells are drilled straight down to depths ranging from 6,000 feet to more than 14,000 feet, cutting through dozens of geological layers, including pockets of drinking water.