Encyclopedia entry
Prospects for geosynthetic containment system at Marcellus formation shale-gas drilling projects
Geosynthetics, Vol.28(1), pp.41-44
WTI-Frankfurt-digital GmbH
Feb 2010
Abstract
The Marcellus Formation, also known as the Marcellus Subgroup of the Hamilton Group, Marcellus Member of the Romney Formation, or simply the Marcellus Shale, is a unit of marine sedimentary rock found in eastern North America. In April 2009, the U.S. Department of Energy estimated the Marcellus contains 262 trillion cubic feet of recoverable gas. State University of New York geology professor Gary Lash has calculated that more than 500 trillion cubic feet of natural gas may be contained in the Marcellus black shale beds that lie between New York state and West Virginia. The Marcellus shale formation is extremely thick in its central locations, e.g., about 900 ft in Pennsylvania, and it 'pinches' out in the west by the Cincinnati Arch and in the north by Canada. Unfortunately, a major factor in the recovery of gas from the formation is that it is deep. It is, for example, 5000 ft in most locations and drilling must go through the upper formations to reach the gas reserves. To capture the gas, two drilling technologies are used. One is horizontal drilling, with a vertical well reoriented to the horizontal so that it penetrates a maximum number of vertical rock fractures and extends a maximum distance within the gas-bearing rock. At least 4,000 new oil and gas wells were drilled in Pennsylvania in 2008, more than in any other state except Texas. Oil and gas wells generate about nine million gallons of wastewater per day in Pennsylvania, according to industry estimates used by the Department of Environmental Protection (DEP). By 2011, that figure is expected to rise to at least 19 million gallons. That's more than all of the state's combined waterways can safety absorb. Much of the wastewater is the by-product of the drilling process called hydraulic fracturing (or 'fracking'), which pumps at least a million gallons of water per well into the targeted formation to break the layers of rock and release the gas. When the water is depressurized and brought back to the surface, it can contain natural toxins accumulated during drilling, including cadmium and benzene. It can also contain small amounts of chemicals added to enhance drilling. At minimum, geomembrane - and possibly geosynthetic clay liner barrier - systems can provide for long-term detention of the waste brine. As seen in the aerial photograph above, a relatively small 'self-contained' enterprise consists of the drilling operation and ancillary equipment along with a surface impoundment. While each surface impoundment is quite small (typically about 2.5 acres or 1.0 ha), when multiplied by the number of wells there is a very large market for geosynthetics in this type of application.
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Details
- Title
- Prospects for geosynthetic containment system at Marcellus formation shale-gas drilling projects
- Creators
- Robert M Koerner
- Publication Details
- Geosynthetics, Vol.28(1), pp.41-44
- Publisher
- WTI-Frankfurt-digital GmbH
- Resource Type
- Encyclopedia entry
- Language
- English
- Academic Unit
- [Retired Faculty]
- Identifiers
- 991020546691704721