A statistical evaluation of formation disturbance produced by well- casing installation methods

Ground Water
By: , and 

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Abstract

Water-resources investigations concerned with contaminant transport through aquifers comprised of very loose, unconsolidated sediments have shown that small-scale variations in aquifer characteristics can significantly affect solute transport and dispersion. Commonly, measurement accuracy and resolution have been limited by a borehole environment consisting of an annulus of disturbed sediments produced by the casing-installation method. In an attempt to quantify this disturbance and recognize its impact on the characterization of unconsolidated deposits, three installation methods were examined and compared in a sand-and-gravel outwash at a test site on Cape Cod, Massachusetts. These installation methods were: 1) casing installed in a mud-rotary hole; 2) casing installed in an augered hole; and 3) flush-joint steel casing hammer-driven from land surface. Fifteen wells were logged with epithermal neutron and natural gamma tools. Concludes that augering is the most disruptive of the three casing-installation methods and that driving casing directly, though typically a more time-consuming operation, transmits the least amount of disturbance into the surrounding formation. -from Authors

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A statistical evaluation of formation disturbance produced by well- casing installation methods
Series title Ground Water
DOI 10.1111/j.1745-6584.1988.tb00385.x
Volume 26
Issue 2
Year Published 1988
Language English
Publisher Wiley
Contributing office(s) Toxic Substances Hydrology Program
Description 11 p.
First page 207
Last page 217
Country United States
State Massachusetts
Other Geospatial Cape Cod
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