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Basalt-flow imaging using a high-resolution directional borehole radar

By:
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DOI: 10.1117/12.462208

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Abstract

A new high-resolution directional borehole radar-logging tool (DBOR tool) was used to log three wells at the Idaho National Engineering and Environmental Laboratory (INEEL). The radar system uses identical directional cavity-backed monopole transmitting and receiving antennas that can be mechanically rotated while the tool is stationary or moving slowly in a borehole. Faster reconnaissance logging with no antenna rotation was also done to find zones of interest. The microprocessor-controlled motor/encoder in the tool can rotate the antennas azimuthally, to a commanded angle, accurate to a within few degrees. The three logged wells in the unsaturated zone at the INEEL had been cored with good core recovery through most zones. After coring, PVC casing was installed in the wells. The unsaturated zone consists of layered basalt flows that are interbedded with thin layers of coarse-to-fine grained sediments. Several zones were found that show distinctive signatures consistent with fractures in the basalt. These zones may correspond to suspected preferential flow paths. The DBOR data were compared to core, and other borehole log information to help provide better understanding of hydraulic flow and transport in preferential flow paths in the unsaturated zone basalts at the INEEL.

Additional Publication Details

Publication type:
Conference Paper
Publication Subtype:
Conference Paper
Title:
Basalt-flow imaging using a high-resolution directional borehole radar
DOI:
10.1117/12.462208
Volume
4758
Year Published:
2002
Language:
English
First page:
13
Last page:
18
Number of Pages:
6
Conference Title:
9th International Conference on Ground Penetrating Radar
Conference Location:
Santa Barbara, CA
Conference Date:
29 April 2002 through 2 May 2002