What is vitrinite reflectance?
What is vitrinite reflectance?
Vitrinite reflectance is the proportion of incident light reflected from a polished vitrinite surface. Vitrinite is a maceral (an organic component) of coal. As vitrinite is heated in the earth during burial, it systematically changes its reflective properties.
Where is the Marcellus Shale located?
The Marcellus Middle Devonian-age organic-rich formation, also known as Marcellus Shale, extends in the subsurface from New York State in the north to northeastern Kentucky and Tennessee in the south and is the most prolific natural gas-producing formation in the Appalachian basin.
How was Marcellus Shale formed?
How did the Marcellus Shale form? About 390 million years ago, what is now western Pennsylvania was part of a large inland sea. Biological matter and organisms dropped to this sea floor over time and mixed with sediments brought into the sea by rivers from the surrounding landmass.
How deep is the Marcellus Shale in WV?
The Marcellus Shale natural gas deposits are located at depths of 3,000 feet in Ohio dipping to more than 9,000 feet in depth eastward near the Virginia border, and the average depth of Marcellus Shale wells in West Virginia is 5,300 feet (Figure 2).
How is vitrinite reflectance used as an indication of maturity of source rocks?
The key attraction of vitrinite reflectance in this context is its sensitivity to temperature ranges that largely correspond to those of hydrocarbon generation (i.e. 60 to 120 °C). This means that, with a suitable calibration, vitrinite reflectance can be used as an indicator of maturity in hydrocarbon source rocks.
How does Marcellus Shale impact the environment?
Marcellus Shale and the Impact on the Environment Exploring, drilling, and extracting natural gas within the Marcellus Shale area can potentially impact Pennsylvania’s surface and groundwater, soils, and wildlife habitats.
What are the issues surrounding the Marcellus Shale?
One concern is that hydraulic fracturing or faulty well construction might damage groundwater and drinking water wells by introducing chemicals, natural gas,7 and other contaminants into aquifers. A second issue is the potential contamination of water wells from surface activities related to gas production.
What is the difference between kerogen and bitumen?
Kerogen—the organic matter that is solid and insoluble in organic solvents—is a key component of organic-rich mudstones. Kerogen is consumed during thermal maturation, whereas bitumen is an intermediary formed at low maturity from kerogen and consumed at higher maturities in formation of oil and gas.
How does kerogen affect the creation of oil and gas?
Kerogen is a waxy, insoluble organic substance that forms when organic shale is buried under several layers of sediment and is heated. If this kerogen is continually heated, it leads to the slow release of fossil fuels such as oil and natural gas, and also the non-fuel carbon compound graphite.
