|Title||Borehole geophysical calibration facilities of the Geological Survey of Canada in Ottawa, Canada: an update|
|Author||Crow, H; Brewer,
K; Cartwright, T; Pugin, A J -M|
|Source||SAGEEP 2018, technical program; 2018 p. 1 Open
|Links||Online - En ligne|
|Alt Series||Natural Resources Canada, Contribution Series 20180213|
|Publisher||Environmental and Engineering Geophysical Society|
|Meeting||SAGEEP 2018 - Symposium on the Application of Geophysics to Environmental and Engineering Problems 2018; Nashville, TN; US; March 25-29, 2018|
Aquifer Assessment & support to mapping|
|Released||2018 03 01|
|Abstract||Calibration 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.
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.