Optimal Configuration of Water Networks in Shale Gas Hydraulic Fracturing Involving Economic and Environmental Considerations

Through the recycling and reuse of wastewater streams, this chapter presents an optimization strategy for constructing effective water networks for shale gas production. This approach reduces freshwater consumption and effluents while considering economic and environmental goals. The goal of the economic objective function is to reduce the total annual cost of the water network, which includes the costs of freshwater, treatment, and transportation in addition to the capital expenditures related to storage, treatment, and disposal. Through an environmental function that represents the advantage of removing pollutants using the eco-indicator 99 methodology, the environmental objective is addressed to deal with the minimization of the environmental impact associated with the discharged concentration of total dissolved solids in the wastewater streams and the freshwater consumption. According to the technique, the available hydraulic fracturing teams must adhere to a specified schedule for the target wells’ completion phases to be carried out within a certain amount of time. The model formulation is set up to identify the ideal dimensions for the project's equipment; in particular, the optimization procedure quantifies the sizes of the storage and treatment units. A case study is resolved to assess the efficacy of the suggested optimization strategy.