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By the USGS Appalachian Basin Province Assessment Team: Debra K. Higley, William A. Rouse, Catherine B. Enomoto, Michael H. Trippi, Timothy R. Klett, Tracey J. Mercier, Michael E. Brownfield, Marilyn E. Tennyson, Ronald M. Drake II, Thomas M. Finn, Nicholas J. Gianoutsos, Ofori N. Pearson, Colin Doolan, Phuong A. Le and Christopher J. Schenk. USGS Fact Sheet 2016–3085, November 2016.
Using a geology-based method, the U.S. Geological Survey estimated a mean of 464 million barrels of oil and 4.08 trillion cubic feet of gas — undiscovered, technically recoverable, continuous resources — in the Lower Mississippian Sunbury Shale and the Middle Devonian–Lower Mississippian Chattanooga Shale of the Appalachian Basin Province.
The five assessment units. Base: National Park Service. Map: USGS.
The assessment
In 2016 the USGS assessed the two shales across parts of Alabama, Georgia, Kentucky, Maryland, Mississippi, New York, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia. It rests on the Devonian Shale–Middle and Upper Paleozoic Total Petroleum System:
- Source rocks: how rich and mature they are, and how oil and gas were generated, adsorbed and moved.
- Reservoirs: type, distribution, porosity, permeability, brittleness.
- Traps and seals, and their timing.
Both shales are organic-rich marine shales, and their oil and gas are considered self-sourced. The USGS defined five continuous assessment units and quantified four. The fifth, the Chattanooga Plateau Shale Oil unit, is hypothetical: there were too few data.
Key inputs (calculated means): success ratios of 28, 28, 50 and 50 percent; well drainage areas of 147, 133, 127 and 87 acres; and average recovery per well of 0.052 million barrels of oil (Sunbury oil) and 0.086, 0.092 and 0.107 billion cubic feet of gas. Every unit's probability was 1.0.
The results
Fully risked means with F95–F5 ranges (F95 means a 95 percent chance of at least that amount):
| Assessment unit | Oil (MMBO) | Gas (BCFG) | NGL (MMBNGL) |
|---|---|---|---|
| Sunbury Shale Oil | 464 (104–1,012) | 1,237 (259–2,800) | 37 (7–88) |
| Sunbury Shale Gas | — | 1,098 (250–2,386) | 13 (3–30) |
| Chattanooga Plateau Shale Gas | — | 610 (102–1,552) | 15 (2–39) |
| Devonian Foldbelt Shale Gas | — | 1,139 (119–3,054) | 11 (1–32) |
| Total | 464 (104–1,012) | 4,084 (730–9,792) | 76 (13–189) |
MMBO: million barrels of oil. BCFG: billion cubic feet of gas. MMBNGL: million barrels of natural gas liquids.
The gas total, 4,084 billion cubic feet, is about 4.08 trillion cubic feet. Background on both shales: Milici and Swezey, USGS Open-File Report 2006–1237. More assessments: the USGS Energy Resources Program.
Sources
Based on Assessment of Undiscovered Oil and Gas Resources of the Mississippian Sunbury Shale and Devonian–Mississippian Chattanooga Shale in the Appalachian Basin Province, 2016, USGS Fact Sheet 2016–3085, U.S. Geological Survey; a work of the United States government in the public domain. The map and the input and results tables are taken from the fact sheet's PDF. The summary calls the gas total "4.08 trillion cubic feet of gas liquids"; it is gas.
Licenza: CC0 1.0 (pubblico dominio) · Tratto da pubs.usgs.gov
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