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TitleBorehole geophysical calibration facilities of the Geological Survey of Canada in Ottawa, Canada: an update
 
AuthorCrow, HORCID logo; Brewer, K; Cartwright, T; Pugin, A J -M
SourceSAGEEP 2018, technical program; 2018 p. 1 Open Access logo Open Access
LinksOnline - En ligne
Image
Year2018
Alt SeriesNatural Resources Canada, Contribution Series 20180213
PublisherEnvironmental and Engineering Geophysical Society
MeetingSAGEEP 2018 - Symposium on the Application of Geophysics to Environmental and Engineering Problems 2018; Nashville, TN; US; March 25-29, 2018
Documentserial
Lang.English
Mediaon-line; digital
File formatpdf
ProgramGroundwater Geoscience, Aquifer Assessment & support to mapping
Released2018 03 01
AbstractCalibration sites provide important opportunities for the standardization of downhole instrument response. Using quantitative physical properties from borehole cores, calibration adds value to projects by allowing for data consistency from hole-to-hole, system-to-system, and importantly, over time. The Geological Survey of Canada (GSC) maintains the Bells Corners Calibration Facilities near Ottawa, Canada, which is open to all members of the logging community. An effort is underway to update petrophysical core measurements, maintain standardization for traditional instruments, and conduct logging with newly developed downhole instruments so that sites remain relevant to members of the groundwater, geotechnical, and mineral exploration sectors.
Work will be presented from two Ottawa-area GSC borehole calibration sites, drilled in distinctly different geological settings. In the late 1970's and early 1980's, the GSC developed quantitative borehole calibration facilities, consisting of model calibration boreholes for gamma-ray spectral logging probes with known concentrations of potassium (K), uranium (U), and thorium (Th), and six deep test boreholes drilled in Palaeozoic sedimentary (sandstone, dolomite, shale) and Precambrian (granitic) bedrock. The boreholes were continuously cored, range in depth from 120 - 300 m, and were sited within a 10 to 100 m triangular configuration for cross-hole capabilities.
In 2014, the GSC sampled and cased a 75-m borehole in a thick sequence of fine-grained, post-glacial sediment in a region prone to sensitive clay landslides. The wide range of geophysical and geotechnical properties measured during core testing and geophysical logging has led us to consider the borehole as a valuable calibration site, supporting ongoing geotechnical and hydrogeological studies at the site.
Summary(Plain Language Summary, not published)
Calibration sites provide important opportunities for the standardization of downhole instrument response. Using quantitative physical properties from bedrock cores and constructed model boreholes, calibration adds value to projects by allowing for data consistency from hole-to-hole, system-to-system, and importantly, over time. The Geological Survey of Canada maintains a facility for calibrating and testing borehole geophysical instruments and downhole gamma-ray spectrometers near Ottawa, Canada, which is open to all members of the logging community. This news article for FastTIMES, an electronic newsmagazine for the near-surface geophysical sciences, describes the facility and efforts to maintain the site for ongoing calibration and research initiatives.
GEOSCAN ID311285

 
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