Maximizing net extraction using an injection-extraction well pair in a coastal aquifer

Area of Science:

• Hydrogeology
• Groundwater Management
• Coastal Aquifer Systems

Background:

• Coastal aquifers face challenges with freshwater extraction due to saltwater intrusion.
• Traditional single extraction wells have limitations in maximizing net extraction rates.
• Optimizing well placement and pumping strategies are crucial for sustainable groundwater use.

Purpose of the Study:

• To develop a novel analytical solution for the maximum net extraction rate in an injection-extraction well pair system.
• To evaluate the performance of this new system compared to traditional single extraction wells.
• To provide guidance for designing efficient well-pair systems in coastal environments.

Main Methods:

• Utilized complex potential theory to derive analytical solutions.
• Assumed steady-state, sharp-interface conditions for modeling.
• Performed sensitivity analyses on aquifer parameters and well placement.

Main Results:

• The injection-extraction well-pair system demonstrated up to 50% higher net extraction rates than single wells.
• Maximum net extraction is influenced by aquifer thickness and hydraulic conductivity.
• Optimal net extraction rate increases linearly with the distance between the injection well and the sea.

Conclusions:

• The novel injection-extraction well-pair system offers a significant improvement in net extraction efficiency for coastal aquifers.
• Analytical solutions provide valuable initial guidance for the practical design of such systems.
• This study extends analytical approaches for coastal pumping beyond single-well applications.