Slug Test Analysis to Evaluate Permeability of Compressible Materials

Abstract

The line-fitting methods such as the Hvorslev method and the Bouwer and Rice method provide a rapid and simple means to analyze slug test data for estimating in situ hydraulic conductivity (k) of geologic materials. However, when analyzing a slug test in a relatively compressible geologic formation, these conventional methods may have difficulties fitting a straight line to the semilogarithmic plot of the test data. Data from relatively compressible geologic formations frequently show a concave-upward curvature because of the effect of the compressibility or specific storage (S(s)). To take into account the compressibility of geologic formations, a modified line-fitting method is introduced, which expands on Chirlin's (1989) approach to the case of a partially penetrating well with the basic-time-lag fitting method. A case study for a compressible till is made to verify the proposed method by comparing the results from the proposed methods with those obtained using a type-curve method (Kansas Geological Survey method [Hyder et al. 1994]).

On the validity of modeling concepts for the simulation of groundwater flow in lowland peat areas – case study at the Zegveld experimental field

“…The use of the traditional steady-state formula should be avoided (Hinsby et al, 1992;Surridge et al, 2005) and instead transient formula have to be applied. Transient formulae to interpret slug tests in unconfined aquifers are hardly described in the literature, but the KGS approach (Choi, 2008;Esling and Keller, 2009) and the Dax expression, as suggested by Hinsby et al (1992), can be considered.…”

“…The model incorporates the effects of partial penetration, anisotropy, and the presence of variable conductivity well skins (Esling and Keller, 2009). The KGS formula is presented in Choi et al (2008), where the conventional line-fitting procedures as used for the Hvorslev and the Bouwer and Rice methods are adapted by introducing a modified effective radius, R e . This parameter is dependent on the compressibility of the geologic formation as well as borehole geometry (Chirlin, 1989).…”

Analytical solution for transient groundwater flow during slug test in vertical cutoff walls

“…There are two categories of slug test interpretations : the type curve method and the line‐fitting method. The Cooper et al .…”

“…There are two categories of slug test interpretations [4,5,7]: the type curve method and the line-fitting method. The Cooper et al method [8,9] and the Kansas Geological Survey method [10] are conventional type curve methods; and the Bouwer and Rice method [11,12], which is frequently used in practice, is one of the conventional line-fitting methods.…”

Analytical Interpretation of Slug Test in a Vertical Cutoff Wall

“…There are two categories of slug test interpretations (Choi and Daniel , ; Choi et al ): the type curve method and the line‐fitting method. The type curve method takes into account the compressibility of the porous medium, but requires tremendous effort to consider the narrow boundaries of vertical cutoff walls.…”