述评:水井水力学—水流定律和几何学的影响

Abstract

Water wells are an indispensable tool for groundwater extraction. The analytical and empirical approaches available to describe the flow of groundwater towards a well are summarized. Such flow involves a strong velocity increase, especially close to the well. The linear laminar Darcy approach is, therefore, not fully applicable in well hydraulics, as inertial and turbulent flow components occur close to and inside the well, respectively. For common well set-ups and hydraulic parameters, flow in the aquifer is linear laminar, non-linear laminar in the gravel pack, and turbulent in the screen and the well interior. The most commonly used parameter of well design is the entrance velocity. There is, however, considerable debate about which value from the literature should be used. The easiest way to control entrance velocity involves the well geometry. The influence of the diameter of the screen and borehole is smaller than that of the screen length. Minimizing partial penetration can help to curb head losses.

Review: Hydraulics of water wells—head losses of individual components

“…In unconsolidated porous aquifers, turbulent flow will occur only under the most extreme of circumstances (Houben and Hauschild 2011;Houben 2015). In regular cases, one can assume fully laminar flow up to the wellbore, and calculate the total drawdown in the confined aquifer at steady state by the Thiem (1906) equation, assuming horizontal radially symmetric flow in an isotropic infinite aquifer.…”

The Effect of Grain Size Distribution on Nonlinear Flow Behavior in Sandy Porous Media

“…In the field of reservoir engineering, fluid flow behavior near the well screen controls the efficiency of oil/gas production wells (e.g., Holditz and Morse 1976;Aulisa et al 2009), as well as the efficiency of injection/extraction wells in groundwater resources applications (e.g., Sen 1989;Mathias and Todman 2010;Wen et al 2011Wen et al , 2013Yeh and Chang 2013;Houben 2015;Mathias and Moutsopoulos 2016). Moreover, nonlinear flow at full-aquifer scale in a broad range of geological formations, such as gravel, karstic or fractured aquifers, is widely addressed in the literature (e.g., Moutsopoulos and Tsihrintzis 2005;Moutsopoulos 2007).…”

Many years’ extraction of groundwater in the context of established usable groundwater reserves

“…This leads to the weakening of the construction of the filter and filter column as a result of their, e.g. mechanical erosion (cavitation, abrasion) [2,5]. Weakening of the filter construction may cause more serious failures, e.g.…”