Research papersOptimal water resources management and system benefit for the Marcellus shale-gas reservoir in Pennsylvania and West Virginia

- Bilevel optimization of water resources management for shale gas is proposed.
- The model is applied to Marcellus reservoir in Pennsylvania and West Virginia.
- Comparative analysis is provided between the proposed model and single-level ones.
- The model can output minimized water demands and maximized system benefit.
- Surface water accounts for 80% of water resources and groundwater occupies for 2%.

A major concern associated with current shale-gas extraction is high consumption of water resources. However, decision-making problems regarding water consumption and shale-gas extraction have not yet been solved through systematic approaches. This study develops a new bilevel optimization problem based on goals at two different levels: minimization of water demands at the lower level and maximization of system benefit at the upper level. The model is used to solve a real-world case across Pennsylvania and West Virginia. Results show that surface water would be the largest contributor to gas production (with over 80.00% from 2015 to 2030) and groundwater occupies for the least proportion (with less than 2.00% from 2015 to 2030) in both districts over the planning span. Comparative analysis between the proposed model and conventional single-level models indicates that the bilevel model could provide coordinated schemes to comprehensively attain the goals from both water resources authorities and energy sectors. Sensitivity analysis shows that the change of water use of per unit gas production (WU) has significant effects upon system benefit, gas production and pollutants (i.e., barium, chloride and bromide) discharge, but not significantly changes water demands.