A Finite Layer Formulation for Groundwater Flow to Horizontal Wells

Area of Science:

• Hydrogeology
• Computational Mechanics
• Environmental Engineering

Background:

• Accurate modeling of groundwater flow to horizontal wells in multilayered aquifer systems is crucial for water resource management and contaminant transport studies.
• Existing numerical methods for three-dimensional (3D) flow analysis often involve significant computational costs and complexities, particularly for systems with unconfined layers.
• Horizontal wells are increasingly utilized in aquifer management, necessitating efficient and accurate simulation techniques.

Purpose of the Study:

• To present a new finite layer approach for simulating 3D groundwater flow to horizontal wells in multilayered aquifer systems.
• To incorporate the effects of unconfined flow within the developed modeling framework.
• To demonstrate the method's efficiency and applicability in complex hydrogeological settings.

Main Methods:

• The approach integrates the finite element method (FEM) in the vertical direction with analytical techniques in horizontal spatial directions.
• Vertical discretization is employed, allowing horizontal wells to be represented on a single nodal plane without discretization.
• Analytical eigenfunctions are utilized to decouple weighted residual equations, leading to explicit formulas for global matrices and flow vectors.

Main Results:

• The finite layer method significantly reduces the bandwidth of global matrices and computational cost compared to traditional 3D analysis.
• Validation against existing solutions for transient flow in confined and unconfined aquifers confirms the formulation's accuracy.
• Successful application to a three-layered system demonstrates the method's capability for modeling complex multilayered aquifer scenarios.

Conclusions:

• The presented finite layer approach offers an efficient and accurate solution for simulating 3D groundwater flow to horizontal wells in multilayered aquifer systems.
• The method effectively handles both confined and unconfined flow conditions, enhancing its versatility.
• This technique provides a valuable tool for hydrogeological modeling, particularly for complex systems with horizontal wells.