Estimation of Vertical-Well Yield Using a Coupled Aquifer–Wellbore Flow Model

Seonmin Lee; Sungshin Kim; Min-Ho Koo; Jaeyun Jung

doi:10.7857/JSGE.2026.31.5.100

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2026 Vol.31, Issue 5 Preview Page Next Page

Research Paper

Estimation of Vertical-Well Yield Using a Coupled Aquifer–Wellbore Flow Model 대수층–관내 흐름 연동 수치모델을 이용한 수직정 취수량 산정

31 October 2026. pp. 100-111

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Abstract

Conventional numerical models of vertical wells commonly assume a uniform wellbore head along the screened interval, neglecting head losses generated as inflow accumulates toward the pump. This study developed a coupled aquifer–wellbore flow model that links aquifer-flow simulations using MODFLOW 6 with pipe-flow calculations through FloPy. The well screen was represented by Drain (DRN) cells, with conductance calculated to account for linear and nonlinear head losses in the aquifer and filter pack as well as screen-slot losses. The wellbore head distribution was calculated by considering frictional and momentum head losses, and the DRN conductance and wellbore head were iteratively updated based on cell-by-cell inflows. Steady-state simulations of a homogeneous confined aquifer showed that wellbore-flow losses affected the total intake rate more strongly than nonlinear and screen-slot losses. At an aquifer hydraulic conductivity of 100 m/d and well diameters of 0.1–0.2 m, nonlinear and screen-slot losses reduced the total intake rate by 4.1–7.4%, whereas wellbore-flow losses caused an additional reduction of 9.9–49.2%. These effects became more pronounced with increasing aquifer hydraulic conductivity and decreasing well diameter. Locating the pump at the midpoint of the screened interval divided the wellbore flow between the upper and lower sections and increased the total intake rate by approximately 9.4% relative to a bottom-mounted pump. Decreases in filter-pack hydraulic conductivity and screen open-area ratio reduced the total intake rate, while well efficiency was governed primarily by the ratio of filter-pack to aquifer hydraulic conductivity. These results demonstrate that the uniform-head assumption can substantially overestimate vertical-well intake, particularly for highly conductive aquifers and small-diameter wells, and that coupled aquifer–wellbore modeling provides a more realistic basis for well design and operation.

Keywords

Aquifer–wellbore coupling

MODFLOW 6

Vertical well

Well clogging

Wellbore hydraulics

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Information

Publisher :The Korean Society of Soil and Groundwater Environment
Publisher(Ko) :한국지하수토양환경학회
Journal Title :Journal of Soil and Groundwater Environment
Journal Title(Ko) :지하수토양환경
Volume : 31
No :5
Pages :100-111
Received Date : 2026-09-21
Revised Date : 2026-10-28
Accepted Date : 2026-10-28
DOI :https://doi.org/10.7857/JSGE.2026.31.5.100

Journal of Soil and Groundwater Environment ISSN:1598-6438(Print) 2287-8831(Online) 지하수토양환경

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