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Scientific Drilling The open-access ICDP and IODP journal

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Sci. Dril., 22, 29-33, 2017
https://doi.org/10.5194/sd-22-29-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Technical development
31 May 2017
Facility for testing ice drills
Dennis L. Nielson1, Chris Delahunty1, John W. Goodge2, and Jeffery P. Severinghaus3 1DOSECC Exploration Services, LLC, 2075 S. Pioneer Rd., Salt Lake City, UT 84104, USA
2Department of Earth and Environmental Sciences, University of Minnesota Duluth, Duluth, MN 55812, USA
3Scripps Institution of Oceanography, UC San Diego, 9500 Gilman Drive no. 0244, La Jolla, CA 92093, USA
Abstract. The Rapid Access Ice Drill (RAID) is designed for subsurface scientific investigations in Antarctica. Its objectives are to drill rapidly through ice, to core samples of the transition zone and bedrock, and to leave behind a borehole observatory. These objectives required the engineering and fabrication of an entirely new drilling system that included a modified mining-style coring rig, a unique fluid circulation system, a rod skid, a power unit, and a workshop with areas for the storage of supplies and consumables. An important milestone in fabrication of the RAID was the construction of a North American Test (NAT) facility where we were able to test drilling and fluid processing functions in an environment that is as close as possible to that expected in Antarctica. Our criteria for site selection was that the area should be cold during the winter months, be located in an area of low heat flow, and be at relatively high elevation. We selected a site for the facility near Bear Lake, Utah, USA.

The general design of the NAT well (NAT-1) started with a 27.3 cm (10.75 in.) outer casing cemented in a 152 m deep hole. Within that casing, we hung a 14 cm (5.5 in.) casing string, and, within that casing, a column of ice was formed. The annulus between the 14 and 27.3 cm casings provided the path for circulation of a refrigerant. After in-depth study, we chose to use liquid CO2 to cool the hole. In order to minimize the likelihood of the casing splitting due to the volume increase associated with freezing water, the hole was first cooled and then ice was formed in increments from the bottom upward. First, ice cubes were placed in the inner liner and then water was added. Using this method, a column of ice was incrementally prepared for drilling tests. The drilling tests successfully demonstrated the functioning of the RAID system. Reproducing such a facility for testing of other ice drilling systems could be advantageous to other research programs in the future.


Citation: Nielson, D. L., Delahunty, C., Goodge, J. W., and Severinghaus, J. P.: Facility for testing ice drills, Sci. Dril., 22, 29-33, https://doi.org/10.5194/sd-22-29-2017, 2017.
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Short summary
The North American Testing (NAT) was designed to test critical functions of a Rapid Access Ice Drill (RAID) at a site in northern Utah. The RAID was designed to rapidly drill in Antarctica through over 2500 m of ice and then take a core sample of the bedrock. The system has many innovative features that required field testing before the system was shipped to Antarcitca. The NAT facility consisted of a borehole where we froze a column of ice to test drilling and fluid circulation functions.
The North American Testing (NAT) was designed to test critical functions of a Rapid Access Ice...
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