Integrated Borehole Geophysical Logging for Characterization of the Naval Air Warfare Center, New Jersey

Overview

As part of its applied research initiatives, the USGS Office of Ground Water, Branch of Geophysics (OGW BG) assists in the planning and collection of geophysical logs at the USGS Toxic Substances Hydrology Program's Naval Air Warfare Center (NAWC) research site in New Jersey, where volatile organic compounds have contaminated bedrock. This is an ongoing applied research project conducted in collaboration with other USGS Toxic Substances Hydrology Program scientists.

Purpose & Scope

OGW BG applied geophysical logging research at NAWC is focused on the acquisition of comprehensive suites of standard and advanced borehole geophysical logs. The geophysical data are entered into a database accessible by USGS personnel involved in research at the NAWC site in order to support integrated, interdisciplinary research.

Methods & Activities

OGW BG has conducted a wide range of borehole geophysical surveys at the NAWC site since 2002.

Standard Logs

Ongoing borehole geophysical logging has included standard logs such as caliper, electromagnetic (EM) induction, conductivity/resistivity, fluid resistivity, and fluid temperature. Data are used to aide in the development of the site conceptual framework, in the design of straddle-packer hydraulic tests, and in well completion.

Optical-televiewer, Acoustic-televiewer, and Heat-pulse Flowmeter

Emphasis is being placed on integration of optical-televiewer (OTV), acoustic-televiewer (ATV), and heat-pulse flowmeter (HPFM) advanced logs with standard borehole logs using single-well and multi-well geophysical software. This integration allows for an improved, integrated analysis of all the logs. In this process, OGW BG scientists have worked to train USGS personnel from the New Jersey Water Science Center on techniques to acquire and analyze advanced logs.

Neutron, Sonic, and Spectral Gamma

[Photo: USGS scientist prepares borehole logging tool.]

Alton Anderson (USGS NY WSC) and John Williams (USGS OGW BG) prepare to conduct gamma spectral logging surveys at NAWC research site.

Additional work since 2002 has been directed toward obtaining estimates of formation porosity to support research on matrix diffusion and the application of borehole geophysical methods to support litho-typing of the gamma signatures used to develop the stratigraphic framework of the site. Logging methods used in these efforts include neutron, full waveform sonic, and spectral gamma as well as standard methods. Emphasis is being placed on logging of selected boreholes from which cores were extracted for laboratory physical property analysis. The information from these new and advanced tools is being used to identify and correlate unique lithologic signatures across fault boundaries and to correlate the geologic framework of the NAWC site to larger, basin-scale investigations.

Neutron logging of selected wells at the site in 2002 was conducted in collaboration with the USGS Borehole Geophysics Research Project.

Single-Hole Flowmeter Testing

Flowmeters were used to collect vertical flow profiles under ambient and stressed (pumped) conditions. The profiles indicate where water enters and exits the borehole. These flowmeter profiles, along with open-hole water-level data, were analyzed to determine the location, transmissivity, and head of discrete fractures, fracture zones, or bedding planes. These tests were conducted prior to installation of permanent or temporary well completions at NAWC. The results were used in the characterization of contaminant distribution and in the design of well completions and groundwater sampling plans.

Cross-Borehole Flow Testing Important for Understanding Hydraulic Connections

Cross-borehole flow tests were completed at the NAWC study area in 2005 to 2007 to provide insights into hydraulic connections in fractured and dipping mudstone and sandstone bedrock at the site. The combined use of cross-hole flowmeter logging and water-level monitoring proved to be crucial for characterizing hydraulics and fracture network connectivity in the contaminated fractured bedrock aquifer.

Results & Conclusions

Applied borehole geophysical research at NAWC is ongoing. Initial results and conclusions include the following:

Single-hole flowmeter logs should be collected under ambient and stressed conditions in order to characterize bedrock fractures and the flow regime. The transmissivity, head, and flow information determined from these tests are critical for characterizing contaminant distribution and for informing the design of well completions and groundwater sampling plans.
Cross-borehole flow testing results demonstrated the inadequacy of relying on open-hole water levels to determine interconnections in fractured-rock aquifers and illustrated the importance of flowmeter logging in studies of fracture connectivity. Application of cross-borehole flow tests at other contaminated fractured-bedrock sites could provide insights into hydraulic connections useful in the design and implementation of monitoring and remediation programs.
Integration of advanced logs such as OTV, ATV, and HPFM with standard borehole logs using single and multi-well geophysical software allows for an improved, integrated analysis of all the logs.
Multi-method geophysical surveys can support litho-typing of the gamma signatures used to develop the stratigraphic framework of a site by helping to identify and correlate unique lithologic signatures across fault boundaries and to correlate the geologic framework of the local site to larger, basin-scale investigations.

Photo Gallery

See a FY2002 field work photo gallery.

Support & Collaboration

This research was funded by the USGS Toxic Substances Hydrology Program.

Collaborators include:

Publications

Williams, J.H., Lacombe, P.J., Johnson, C.D., and Paillet, F.L., 2007, Cross-borehole flow tests and insights into hydraulic connections in fractured mudstone and sandstone, in Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 1-5, 2007, Denver, Colorado, Proceedings 2007: Denver, Colorado, Environmental and Engineering Geophysical Society, CD-ROM, p. 1140-1152.

Johnson, C.D., and Williams, J.H., 2006, Use of cross-hole flowmeter logging to characterize fracture connectivity and fracture flow during a pumping test at the NAWC site, West Trenton, New Jersey [abs.]: Geological Society of America Abstracts with Programs, v. 38, no. 7, p. 528, Paper no. 219-10.

Johnson, C.D., Williams, J.H., and Anderson, J.A., 2007, Use of single- and cross-hole flowmeter logging for investigations in contaminated fractured-rock aquifers [abs.]: Proceedings of the Northeast Section Annual Meeting, Durham, New Hampshire, March 12-14, 2007, Geological Society of America.

Related Sites

For more information:

For more information on this project, please contact John W. Lane, Jr. (Chief, USGS OGW Branch of Geophysics) or Carole Johnson (Hydrologist, USGS OGW Branch of Geophysics), or call the Branch of Geophysics at (860)487-7402.

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USGS Programs and Offices can learn more about geophysical equipment available for USGS use and training and support from OGW BG.