scholarly journals Simulation assessment of the direct-push permeameter for characterizing vertical variations in hydraulic conductivity

2008 ◽  
Vol 44 (2) ◽  
Author(s):  
Gaisheng Liu ◽  
Geoffrey C. Bohling ◽  
James J. Butler
Keyword(s):  
Hydraulic Conductivity ◽  
Direct Push ◽  
Vertical Variations

Direct Push Technology and Application to Vertical Profiling of Hydraulic Conductivity in Unconsolidated Formations

2003 ◽  
Author(s):  
Wesley McCall ◽  
Thomas M. Christy ◽  
James J. Butler
Keyword(s):  
Hydraulic Conductivity ◽  
Test Data ◽  
Small Diameter ◽  
Cost Effective ◽  
Depth Interval ◽  
Contaminant Migration ◽  
Slug Tests ◽  
Monitoring Wells ◽  
Direct Push ◽  
Vertical Profiling

Direct push (DP) methods provide a cost-effective alternative to conventional rotary drilling for investigations in unconsolidated formations. DP methods are commonly used for sampling soil gas, soil and groundwater; installing small-diameter monitoring wells; electrical logging; cone penetration testing; and standard penetration tests. Most recently, DP methods and equipment for vertical profiling of formation hydraulic conductivity (K) have been developed. Knowledge of the vertical and lateral variations in K is integral to understanding contaminant migration and, therefore, essential to designing an adequate and effective remediation system. DP-installed groundwater sampling tools may be used to access discrete intervals of the formation to conduct pneumatic slug tests. A small-diameter (38mm OD) single tube protected screen device allows the investigator to access one depth interval per advancement. Alternatively, a larger diameter (54mm OD) dual-tube groundwater profiling system may be used to access the formation at multiple depths during a single advancement. Once the appropriate tool is installed and developed, a pneumatic manifold is installed on the top of the DP rod string. The manifold includes the valving, regulator, and pressure gauge needed for pneumatic slug testing. A small-diameter pressure transducer is inserted via an airtight fitting in the pneumatic manifold, and a data-acquisition device connected to a laptop computer enables the slug test data to be acquired, displayed, and saved for analysis. Conventional data analysis methods can then be used to calculate the K value from the test data. A simple correction for tube diameter has been developed for slug tests in highly permeable aquifers. The pneumatic slug testing technique combined with DP-installed tools provides a cost-effective method for vertical profiling of K. Field comparison of this method to slug tests in conventional monitoring wells verified that this approach provides accurate K values. Use of this new approach can provide data on three-dimensional variations in hydraulic conductivity at a level of detail that has not previously been available. This will improve understanding of contaminant migration and the efficiency and quality of remedial system design, and ultimately, should lead to significant cost reductions.

Multi-scale integrated characterization of heterogeneous hydraulic and thermal properties of a deltaic aquifer

2020 ◽  
Author(s):  
Jean-Marc Ballard ◽  
Cynthia Lee ◽  
Nataline Simon ◽  
Jerome de la Bernardie ◽  
Daniel Paradis ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Hydraulic Conductivity ◽  
Fiber Optics ◽  
Tracer Test ◽  
Future Application ◽  
Quebec City ◽  
Aquifer Characterization ◽  
Characterization Methods ◽  
Direct Push ◽  
Groundwater Flux

<div>Historically, heat and temperature observations have been occasionally used to help understand aquifer systems or constrain numerical flow models. However, the development of fiber optics (FO) as part of the Distributed Temperature Sensing (DTS) technology has spun a renewed interest in the use of heat as a groundwater tracer. Recent studies have shown the possibility to carry out an active heat tracer test using fiber optics and heating cables installed by direct push and to invert the resulting thermal responses to estimate a vertical profile of groundwater fluxes. However, a better understanding of how FO-DTS results compare to other aquifer characterization methods is needed to guide its future application and integration into a practical workflow. The objective of this study was thus to compare the information provided by FO-DTS with other direct and indirect measurements used to characterize the heterogeneity of granular aquifers at multiple scales. </div><div>The multiscale integrated characterization was carried out at a heterogeneous deltaic aquifer located north of Quebec City, Canada. This aquifer has been the object of a complete hydrogeological characterization and thus provides a wide range of existing data against which the acquired data can be compared. This communication will focus on the multiscale methodology for the granular aquifer characterization including FO-DTS measurements. Based on an existing numerical hydrogeological model, three sites with a range of horizontal groundwater fluxes were selected for active FO-DTS heat tracer experiments. At one of the sites, direct push monitoring wells were also installed downstream to measure the hydraulic conductivity of the hydrofacies and the arrival of the thermal front from the heat tracer test. A previous study established a relationship between the hydrofacies of the deltaic aquifer to cone penetration test (CPT) response. As such, each FO cable and monitoring well direct-push installation was preceded by a co-located CPT. Soil cores were also taken for laboratory measurements of hydraulic and thermal properties. </div><div>The vertical profiles of groundwater fluxes from FO-DTS were found to correlate well with the relative magnitude of permeability of the hydrofacies identified with CPT profiles. FO-DTS could thus provide a qualitative or quantitative proxy for hydraulic conductivity and allow the recognition of hydrofacies at a fine scale. At the aquifer scale, the total flux measured by FO-DTS can also be compared to fluxes obtained from numerical models and thus provide a constraint to validate models. Overall, this study shows that not only does FO-DTS provide coherent results with other characterization methods, but it also adds the key measurement of groundwater flux that cannot be easily obtained by other means. FO-DTS thus has the potential to become a significant addition to existing characterization methods for granular aquifers.</div>

A constant-head pumping test method using direct-push equipment for in situ hydraulic conductivity measurements

Géotechnique ◽  
2012 ◽  
Vol 62 (3) ◽  
pp. 253-262 ◽  
Author(s):  
T. KOBAYASHI ◽  
H. ONOUE ◽  
S. OBA ◽  
N. YASUFUKU ◽  
K. OMINE
Keyword(s):  
Hydraulic Conductivity ◽  
Pumping Test ◽  
Test Method ◽  
Conductivity Measurements ◽  
Direct Push ◽  
Constant Head

A dual-tube direct-push method for vertical profiling of hydraulic conductivity in unconsolidated formations

2002 ◽  
Vol 8 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Wesley McCall ◽  
James J. Butler ◽  
John M. Healey ◽  
Alyssa A. Lanier ◽  
Stephen M. Sellwood ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Preferential Flow ◽  
Field Tests ◽  
Small Scale ◽  
Slug Tests ◽  
Monitoring Wells ◽  
Direct Push ◽  
Vertical Profiling ◽  
Discrete Interval ◽  
Sand And Gravel

Abstract A new direct-push procedure has been developed for the purpose of conducting discrete-interval slug tests to define vertical variations in hydraulic conductivity (K.) This approach is an extension of existing dual-tube methods developed for soil sampling. In this procedure, nested rods (tubes) are simultaneously advanced to predetermined test intervals. The inner rods are then removed and a screen is inserted into the formation for slug testing and possible water sampling. Once testing and sampling are completed, the screen is retrieved, the inner rods reinserted, and the system is advanced to the next test interval. A series of field tests were performed in a highly permeable sand and gravel aquifer to assess the effectiveness of this new approach. Dual-tube profiling results were compared to multilevel slug tests conducted in conventional monitoring wells for intervals in which hydraulic conductivity ranged from 175 ft/day to over 800 ft/day. An initial evaluation found that the dual-tube profiling results were in good agreement (< or =12 percent difference) with K values obtained from multilevel slug tests in the closest monitoring well. Two more-detailed profiles demonstrate that the dual-tube method can effectively delineate small-scale vertical and horizontal variations in hydraulic conductivity. This field assessment shows that the dual-tube method is an accurate and efficient procedure for obtaining information about spatial variations in hydraulic conductivity. This information can be useful for selecting intervals for well installations, for assessment of various remediation alternatives, and for identifying preferential flow paths and other features that can control contaminant movement in the subsurface. The information is obtained without the need for permanent wells. Because this is a direct-push procedure, drill cuttings are eliminated and the volume of development water generated is significantly reduced.

Characterising the vertical variations in hydraulic conductivity within the Chalk aquifer

2006 ◽  
Vol 330 (1-2) ◽  
pp. 53-62 ◽  
Author(s):  
A. Williams ◽  
J. Bloomfield ◽  
K. Griffiths ◽  
A. Butler
Keyword(s):  
Hydraulic Conductivity ◽  
Vertical Variations ◽  
Chalk Aquifer

scholarly journals Reassessing the MADE direct-push hydraulic conductivity data using a revised calibration procedure

2016 ◽  
Vol 52 (11) ◽  
pp. 8970-8985 ◽  
Author(s):  
Geoffrey C. Bohling ◽  
Gaisheng Liu ◽  
Peter Dietrich ◽  
James J. Butler
Keyword(s):  
Hydraulic Conductivity ◽  
Calibration Procedure ◽  
Conductivity Data ◽  
Direct Push

Inferring high-resolution aquifer hydraulic conductivity and groundwater fluxes by active heat tracer using direct push fiber optics

2020 ◽  
Author(s):  
Cynthia Lee ◽  
Olivier Bour ◽  
Jean-Marc Ballard ◽  
Nataline Simon ◽  
Jerome de la Bernardie ◽  
...  
Keyword(s):  
High Resolution ◽  
Hydraulic Conductivity ◽  
Fiber Optics ◽  
Tracer Tests ◽  
Tracer Experiment ◽  
Quebec City ◽  
Temperature Profiles ◽  
Vertical Profiles ◽  
Aquifer Heterogeneity ◽  
Direct Push

&lt;div&gt;Characterizing aquifer heterogeneity for contaminant transport prediction remains a challenge in subsurface hydrology. In recent years, fiber optics (FO) Distributed Temperature Sensing (DTS) has enabled the study of transient hydrogeological processes with high spatial and temporal resolutions. Recent studies have shown that vertical profiles of groundwater fluxes can be quantified in granular aquifers through inversion of the thermal responses from active heat tracer tests using FO cables installed by direct push. Here, we further investigate the potential of active FO-DTS methods for granular aquifer characterization by performing a multiscale characterization and active heat tracer experiment in a well-characterized heterogeneous deltaic aquifer located north of Quebec City, Canada. This aquifer has been the object of detailed hydrogeological characterization and thus provides a wide range of existing data. In particular, we will test whether the vertical distribution of groundwater fluxes in the sub-surface determined by these inversions can be used to estimate hydraulic properties at a spatial scale that can be used to assess the impact of aquifer heterogeneity on mass transport and dispersion.&amp;#160;&lt;/div&gt;&lt;div&gt;This communication focuses on a site where two FO cables were installed 10 m apart by direct push. An active heat tracer experiment was carried out with the two FO cables, and the resulting thermal responses were inverted to obtain high-resolution vertical profiles of the groundwater fluxes at each FO cable. Heating was carried out in the saturated zone, between depths of 12 to 40 m with a 25-cm vertical sampling. Using data from a piezometric survey, the groundwater fluxes from the FO-DTS were used to estimate a range of hydraulic conductivities (K). A previous study at the field site has shown that cone penetration test (CPT) profiles can be used to recognize the different hydrofacies with distinct ranges of hydraulic conductivity present in the deltaic aquifer. As the two FO cables were co-located with a previously done CPT profile, the measured fluxes and estimated K values could be compared to known ranges of K.&amp;#160;&lt;/div&gt;&lt;div&gt;Results show quite varying temperature profiles and accordingly distinct groundwater fluxes. These varying fluxes are coherently correlated to the different hydrofacies identified with the co-located CPT responses at a similar vertical scale. The two FO-DTS temperature profiles are also quite similar when considering the small variations in hydrofacies found along their length. These results show that FO-DTS heat tracer tests provide consistent and representative measurements of groundwater fluxes in agreement with the heterogeneous distribution of K as indicated by CPT. Thus, compared with existing hydraulic methods, FO-DTS heat tracer tests provide new and complementary data that have a great potential for characterizing solute transport in granular aquifers with a high spatial resolution.&lt;/div&gt;

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