AAPG Bulletin; May 2006; v. 90; no. 5;
p. 715-734; DOI: 10.1306/10170505030
© 2006 American Association of Petroleum Geologists (AAPG)
Analysis of light hydrocarbons in soil gases, Lost River region, West Virginia: Relation to stratigraphy and geological structures
William Harbert1,
Victor T. Jones2,
John Izzo3 and
Thomas H. Anderson4
1 Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260; harbert{at}pitt.edu
2 Exploration Technologies, Inc., 7755 Synott Road, Houston, Texas 77083
3 Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
4 Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
W. Harbert received an M.S. degree in exploration geophysics and a Ph.D. in geophysics from Stanford University, followed by a National Research Council postdoctoral study at the U.S. Geological Survey. His research includes environmental geophysics work to detect polluted subsurface water and mine voids in close collaboration with the National Energy Technology Laboratory at the U.S. Department of Energy. His research activities resulted in his being chosen by the governor of Pennsylvania to serve on the Governor's Commission Investigating Mine Voids and Mine Safety.
Victor T. Jones obtained his Ph.D. in physics at Texas A&M University in 1969. Jones, an internationally recognized leader in surface geochemical methods, has more than 30 years of experience in research, management, execution, and interpretation of geochemical programs pertaining to petroleum and minerals exploration and environmental assessments. He has designed geochemical exploration programs for field operations onshore and offshore throughout the world and has generated more than 100 proprietary geochemical interpretation reports on the geochemistry of domestic United States and international basins. Jones has developed new instruments for the measurement of benzene and toluene by second-derivation spectroscopy for mud logging and has extensive experience in the use of mercury as a volatile pathfinder for mineral deposits, including silver and gold. Additionally, Jones has directed over 200 environmental impact evaluations using geochemical methods.
John Izzo completed his B.S. degree at Duquesne University and an M.S. degree in geology at the University of Pittsburgh. He is presently employed as a geoscientist at the RJ Lee Group in Monroeville, Pennsylvania.
Thomas H. Anderson is a professor at the University of Pittsburgh with interests in structural geology and tectonics. He received his B.A. degree from Franklin and Marshall College and an M.A. degree and a Ph.D. in geology from the University of Texas at Austin. Subsequently, he worked as a research fellow at Caltech, where he applied U-Pb isotopic analyses of zircon to define regional magmatic domains in northwestern Mexico. Currently, his research focuses on the Appalachian and Cordilleran mountain belts of North America.
Analyses of 471 near-surface soil-gas samples for light hydrocarbons, C1–C4, C2L, C3L, and H2 from the Lost River gas field in Hardy County, West Virginia, reveal sites or clusters of sites containing anomalously high concentrations of light hydrocarbon gases, which occur directly over the faulted, eastern limb of the Whip Cove anticline. Compositional changes in the soil-gases data clearly define major changes in the maturity and locations of potential source beds. Grids placed on botanically defined anomalies confirm a possible correlation between these two independent indicators. Statistical analysis shows that samples from 45 sites contain anomalously large concentrations of light hydrocarbons in the soil-gas constituents. Large concentrations, coupled with high saturate-to-olefin ratios, further confirms that this active seepage is near macroseep levels. Variations in soil-gas compositional trends separate the soil-gas data into two domains, with oilier compositions to the west and gassier compositions to the east. Although the composition of the shallow soil gases above the Lost River gas field are oilier than the reservoir gases, they occur directly over the eastern, faulted limb of the producing anticlinal structure, suggesting that the dry gases from the Oriskany reservoir are probably mixed with oilier gases from organic-rich strata among Devonian shales. The eastern anomalies are much gassier and are very similar to the Oriskany gases produced by the Lost River gas field. The eastern anomalies directly overlie near-vertical beds of Devonian and older age formations that are likely conduits for deeper, mature thermal gases.
Copyright © 2009 by American Association of Petroleum Geologists (AAPG)
