Abstract
An analytical solution is presented for groundwater flow to a well in an aquifer with double-porosity behavior and transient transfer between fractures and matrix. The solution is valid for fractional flow dimensions including linear, cylindrical or spherical flow to the well and for fractional inter-porosity diffusive transfer including release from storage in infinite slabs, infinite cylinders or spherical matrix blocks. Approximations are also presented for small and large times that are easy to evaluate in practice. The solution can be used to analyze pumping tests via coupling with a parameter estimation code. The utility of the method is demonstrated by a practical example using data from a pumping test performed in a fractured chalk aquifer. The analytical solution allows the accurate modeling of pumping tests and the estimation of aquifer parameters that are statistically significant and physically relevant.
Highlights
Double-Porosity Aquifer withThe concept of double porosity explains groundwater flow in fractured aquifers, by considering the matrix as a primary porous system with low hydraulic conductivity and high storage capacity and the fractures as a secondary porous system with high hydraulic conductivity and low storage capacity [1]
The solution presented in this study extends the work of previous studies by deriving an analytical solution for groundwater flow to a pumping well in a fractured aquifer with transient exchange between matrix blocks and fractures
An analytical solution for well flow in fractured porous media was presented based on the double-porosity approach with transient exchange between fractures and matrix
Summary
The concept of double (or dual) porosity explains groundwater flow in fractured aquifers, by considering the matrix as a primary porous system with low hydraulic conductivity and high storage capacity and the fractures as a secondary porous system with high hydraulic conductivity and low storage capacity [1]. Groundwater mainly flows through the fractures while the rock matrix releases fluid to the fractures at a limited rate due to its low permeability. Two approaches have been proposed to quantify the exchange of water between the fractures and the matrix: (1) pseudo-steady-state flow assuming an exchange rate proportional to the difference in hydraulic head between the fractures and the matrix [1,2,3], and (2) transient flow where the exchange rate is determined by diffusive flow in the matrix blocks to the fractures [4,5,6]. Applications show that both approaches have their merits [6,7,8], as the pseudo-steady-state approach has the advantage of mathematical simplicity, while the transient approach is superior from a theoretical and physical point of view
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
