Borehole Geophysics as Applied to Geohydrology

A large amount of geophysical data is recorded in water wells and test holes but interpretation is subject to significant uncertainties. The data are used in ground-water models; to evaluate potential waste disposal sites; the effects of ground- water contamination, and to guide aquifer development, including geothermal reservoirs. The development of quantitative log interpretation techniques to derive more accurate data and to evaluate the statistical uncertainities in the data will reduce costs in ground-water investigations. Project objectives are to evaluate presently available logging equipment and log intrepretation techniques and develop improved instrumentation and analytical techniques for specific ground-water problems such as: site selection and monitoring for disposal of radioactive, municipal, and industrial wastes; improve log derived data such as porosity; attempt to relate the log character of fractures to their hydraulic conductivity and to refine computer techniques for plotting hydraulic conductivity proflies from logs; develop the capability of making quantitative intrepretation of borehole gamma spectra; and to make a statistical analysis of the magnitude and sources of errors in log derived data. For additional information, see project's home page.

REPORTS PUBLISHED 2002-2003

Day-Lewis, F.D., Johnson, C.D., Paillet, F.L., and Halford, K.J., 2011, A Computer Program for Flow-Log Analysis of Single Holes (FLASH): Ground Water, v. 49, no. 6, p. 926-931. (on-line abstract of journal article)

Paillet, F.L., 2004, Discussion of "Implications of Observed and Simulated Ambient Flow in Monitoring Wells, by Alper Elci, Fred J. Molz III, and W. R. Waldrop, November-December 2001 issue, v. 39, no. 6: 853-862": Ground Water, v. 42, no. 1, p. 137-138

Paillet, F.L., Molz, F.J., and Elci, A., 2004, "Implications of Observed and Simulated Ambient Flow in Monitoring Wells," by Alper Elci, Fred J. Molz III, and W. R. Waldrop, November-December 2001 issue, v. 39, no. 6: 853-862": Ground Water, v. 42, no. 1, p. 137-139.

Benson, L., Kashgarian, M.; Rye, R., Lund, S., Paillet, F., Smoot, J., Kester, C., Mensing, S., Meko, D., and Lindstrom, S., 2002, Holocene multidecadal and multicentennial droughts affecting Northern California and Nevada: Quaternary Science Reviews, v. 21, p. 659-682. (on-line abstract)

Benson, L.V., Paillet, F.L., 2002, HIBAL: A hydrologic-isotopic-balance model for application to paleolake systems: Quaternary Science Reviews, v. 21, p. 1521-1539. (on-line abstract)

Paillet, F.L., Williams, J.H., Oki, D.S., Knutson, K.D., 2002, Comparison of Formation and Fluid-Column Logs in a Heterogeneous Basalt Aquifer: Ground Water, v. 40, no. 6, p. 577-585. (on-line abstract)

Williams, J.H., and Paillet, F.L., 2002, Using flowmeter pulse tests to define hydraulic connections in the subsurface: A fractured shale example: Journal of Hydrology, v. 265, p. 100-117. (on-line abstract)