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

R. H. Morin; Denis R. LeBlanc; W.E. Teasdale

doi:10.1111/j.1745-6584.1988.tb00385.x

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

R. H. Morin·Denis R. LeBlanc·W.E. Teasdale

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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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Source-reported bounding extent: 41.6154423246811° to 42.16340342422401° latitude; -70.83984375° to -69.862060546875° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

R. H. Morin, Denis R. LeBlanc, W.E. Teasdale. 2006-03-21. A statistical evaluation of formation disturbance produced by well- casing installation methods. https://doi.org/10.1111/j.1745-6584.1988.tb00385.x

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