Modeling flow into horizontal wells in a Dupuit-Forchheimer model

Area of Science:

• Hydrogeology
• Water Resource Engineering

Background:

• Horizontal and radial collector wells enhance water withdrawal in shallow aquifers.
• Accurate modeling of 3D groundwater flow near these wells is computationally intensive.
• Simplified models are needed for efficient water withdrawal system design.

Purpose of the Study:

• To develop a simplified modeling approach for horizontal wells in shallow aquifers.
• To accurately predict groundwater withdrawal rates and delineate capture zones.
• To provide a computationally efficient alternative to 3D numerical models.

Main Methods:

• Developed a Cauchy boundary condition for horizontal wells within a Dupuit-Forchheimer (steady-state 2D) model.
• Applied the model to radial collector wells and horizontal wells beneath rivers.
• Compared model results with 3D numerical simulations.

Main Results:

• The Dupuit-Forchheimer model accurately predicts production rates for radial collector wells, closely matching 3D model outcomes.
• Satisfactory results were obtained for horizontal wells under rivers, especially with moderate-to-large riverbed resistance.
• The 2D model offers a viable alternative for designing water withdrawal systems and source water protection.

Conclusions:

• A steady-state 2D Dupuit-Forchheimer model with a Cauchy boundary condition effectively simulates groundwater withdrawal from horizontal wells.
• This approach simplifies the design of water withdrawal systems and aids in capture zone delineation.
• The model provides accurate production rates, comparable to complex 3D simulations, for practical hydrogeological applications.