Shale Gas Geology

From the big, dizzy mountains that screen it To the deep, deathlike valleys below. 

Maybe but there s some as would trade it For no land on earth—and I m one. 

Geologists can read these layers of sedimentary rock like the pages of a 

A sedimentary rock is a clue to the past it is filled with memories of splendor and horror. 

To get even closer to the margin of understanding shale gas and hydraulic fracturing one must have a fundamental, foundational, basic knowledge of sedimentary geology. For this reason, this chapter presents very basic coverage of sedimentary geology. 

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Zhang, J.C. Nie, H.K. 2008 Geology Condition of Shale Gas Accumulation in Sichuan Basin. Natural Gas... 

Because natural gas bums cleanly, the nation s domestic natural gas resources, and the presence of supporting infrastructure, the development of domestic shale gas reserves will be an important component of the United States energy coffer for many years. Recent successes in a variety of geologic basins have created the opportunity for shale gas to be a strategic part of the nation s energy and economic growth (IPAMS, 2008). 

In order to grasp the information pertinent to the nature of geologic shale formations discussed in this text it is important to have an understanding of the geologic time scale. Table 5.1 is provided on the following pages to help the reader correlate the relationship between each shale gas formation discussed and where each resides within the spectrum of the geologic time scale. 

The New Albany Shale is an organic-rich geologic formations located in the Illinois Basin in portions of southern Illinois, southwestern Indiana, and northwestern Kentucky (IGS, 1986). Similar to the Antrim Shale, the New Albany Shale occurs at depths between 500 and 2000 feet (Table 5.8) and is a shallower, water-filled shale with a more CBNG-like character than the other gas shales discussed in this text. The New Albany formation is a Devonian- to Mississippian-age Shale bounded by limestone above (Rockford Limestone) and below (North Vernon Limestone) (Figure 5.8). The New Albany Shale is one of the largest shale gas plays, encompassing an area of approximately 43,500 square miles with approximately 80-acre spacing between wells. Similar to the Antrim Shale, the New Albany play has a... 

Natural Gas. Oil Shales, and Tar Sands. Natural gas is not fotmally defined as a component of crude petroleum, although natutal gas commonly exists in the same geological formations, often directly in contact with crude petroleum. However, a large percentage of natural gas wells are not associated with producing oil wells. See also Natural Gas. 

Fossil fuel resources a gaseous, liquid, or solid fuel material formed in the ground by chemical and physical changes (diagenesis, q.v.) in plant and animal residues over geological time natural gas, petroleum, coal, and oil shale. 

Substances consisting largely of hydrocarbons, derived from decay of organic materials under geological conditions of high pressure and temperature (metamorphism) include coal, petroleum, natural gas, peat and oil shale. 

Petroleum formed from the remains of microorganisms that lived in Earth s oceans millions of years ago. Over time, the remains formed thick layers of mudMke deposits on the ocean bottom. Heat from Earth s interior and the tremendous pressure of overlying sediments transformed this mud into oil-rich shale and natural gas. In certain kinds of geological formations, the petroleum ran out of the shale and collected in pools deep in Earth s crust. Natural gas, which formed at the same time and in the same way as petroleum, is usually found with petroleum deposits. Natural gas is composed primarily of methane, but it also has small amounts of alkanes having two to five carbon atoms. 

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