| Title | Single-well interference slug tests to assess the vertical hydraulic conductivity of unconsolidated aquifers |
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| Author | Paradis, D ;
Lefebvre, R |
| Source | Journal of Hydrology vol. 478, 2013 p. 102-118, https://doi.org/10.1016/j.jhydrol.2012.11.047 |
| Image |  |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20100189 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | hydrogeology; geophysics; aquifers; groundwater; groundwater regimes; conductivity; hydraulic conductivity; hydraulics; hydraulic analyses; modelling; hydrostratigraphic units |
| Illustrations | plots; logs |
| Program | Groundwater Geoscience Aquifer Assessment &
support to mapping |
| Released | 2013 01 01 |
| Abstract | Meaningful understanding of flow and solute transport in general requires the knowledge of hydraulic conductivity and its anisotropy. Various field methods allow the measurement of the horizontal
component (Kh), but vertical hydraulic conductivity (Kv) is rarely measured, for lack of practical field tests. This paper proposes vertical interference slug tests, an adaptation of inter-well interference slug tests to a single well, for the
efficient field measurement of Kv. The test is carried out in a single well between a stress and an observation interval that are vertically isolated with a three-packer assembly. An instantaneous pressure pulse is induced in the stress interval and
resulting drawdowns are recorded in both the stress and the observation intervals. In a proof-of-concept field study, 12 vertical interference tests were carried out sequentially along a fully-screened well across a moderately heterogeneous and
highly anisotropic aquifer made up of littoral silts and sands. A direct-push method was used to install the well, which was completed without sand-pack to allow the natural collapse of sediments in the thin annular space around the screen.
Direct-push wells allow the measurement of in situ hydraulic properties of sediments and minimize well construction interferences with hydraulic tests. Drawdowns measured in stress and observation intervals of multiple tests were simultaneously
inverted numerically to reconstruct heterogeneous profiles of Kh, hydraulic conductivity anisotropy (Kv/Kh), and specific storage (Ss). Results were validated by comparison of observed versus predicted drawdowns and with field and laboratory
measurements of Kh and Kv made along the tested well. Results indicate that the profile of Kv values obtained with vertical interference slug tests follows a similar pattern with depth than the profile with lab measurements made with a permeameter on
soil samples collected in the same intervals as the interference tests, which demonstrates that vertical interference slug tests could provide an efficient method for the field measurement of well-scale Kv values. |
| GEOSCAN ID | 286260 |
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