Non-Darcian flow to a partially penetrating well in a confined aquifer with a finite-thickness skin

2016 ◽  
Vol 24 (5) ◽  
pp. 1287-1296 ◽  
Author(s):  
Qinggao Feng ◽  
Zhang Wen
Keyword(s):  
Finite Thickness ◽  
Confined Aquifer ◽  
Thickness Skin ◽  
Partially Penetrating Well

Evaluation of Slug Tests in Wells Containing a Finite-Thickness Skin

1984 ◽  
Vol 20 (4) ◽  
pp. 504-506 ◽  
Author(s):  
Charles R. Faust ◽  
James W. Mercer
Keyword(s):  
Finite Thickness ◽  
Slug Tests ◽  
Thickness Skin

Diffusive contaminant transport in a multi-layered aquifer-aquitard system

2021 ◽  
Author(s):  
Seonggan Jang ◽  
Minjune Yang
Keyword(s):  
Analytical Solutions ◽  
Experimental Validation ◽  
Finite Thickness ◽  
Unconfined Aquifer ◽  
Flow Chamber ◽  
Measured Data ◽  
Solute Diffusion ◽  
Confined Aquifer ◽  
State Diffusion ◽  
Two Dimensional Flow

<p>A flow chamber experiment was conducted to investigate solute diffusion in a multi-layered aquifer-aquitard system. The two-dimensional flow chamber consisted of a finite thickness aquitard (kaolinite, 2 cm) bounded by two parallel aquifers at the top (unconfined aquifer, 2 cm) and bottom (confined aquifer, 4 cm). New Coccine (red dye) of 500 mg/L in the top aquifer and distilled water in the bottom aquifer were injected with 0.02 mL/min for 13 days. One-dimensional analytical solutions were developed for advection and diffusion through a finite aquitard and compared with the measured data to evaluate experimental validation. The simulated aquitard concentration profiles (E > 0.97) and breakthrough curve (E = 0.95) showed good agreement with the measured data. During the experiment, the penetration distance in the aquitard increased over time and the vertical concentration distribution showed a linear profile through the aquitard after 7 days of loading in the top aquifer, indicating steady-state diffusion. The New Coccine diffused across the aquitard to the bottom aquifer after 1 day of loading. The bottom aquifer concentration increased at early times and was maintained after 7 days of loading (11 ~ 12 mg/L). This study provides experimental validation of the developed analytical solutions and quantitatively evaluates contaminant occurrences of the confined aquifer through the aquitard.</p>

Interpretation of the transient flow rate obtained from constant-head tests conducted in situ in clays

1993 ◽  
Vol 30 (4) ◽  
pp. 600-606 ◽  
Author(s):  
K.S. Novakowski
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Finite Thickness ◽  
Skin Permeability ◽  
Type Curves ◽  
Partial Penetration ◽  
Thickness Skin ◽  
Skin Zone ◽  
Constant Head

Hydraulic tests conducted in situ using a source condition of constant head are frequently employed to determine the hydraulic properties of low-permeability clays. In this paper, an analytical model is developed for analyzing the results of a constant-head test conducted under conditions where the influence of finite-thickness skin and partial penetration are present at the source well. The analytical model is derived by application of the Laplace transform method with respect to time and the finite Fourier cosine transform with respect to the vertical coordinate. The solution is used to produce type curves of dimensionless flow rate versus dimensionless time so as to investigate the influence of finite thickness skin and partial penetration on the results of constant-head tests. Results show that the presence of a skin zone of finite thickness having permeability less than the formation produces an inflection point in the type curves at which point the dimensionless flow rate tends asymptotically towards a steady value. For the case where the skin and formation permeabilities are similar, these type curves can be used to uniquely define both the skin and formation properties. Where the skin zone is very thin, the shape of the type curves mimics the curve for a uniform, fully confined medium, and thus only the properties of the skin are measured using type-curve analysis. Conversely, the type curves for the case where the skin zone is of greater permeability than the formation show a unique and interpretable shape for each skin thickness and ratio of formation to skin permeability over most practical values of hydraulic diffusivity. Additional effects due to partial penetration were found to be pronounced in piezometers completed with small screen lengths. Particular conditions where the conventional steady approximation can be used are also discussed. Key words : constant-head test, flow rate, skin zone, partial penetration.

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