Disclosing water-energy-economics nexus in shale gas development

Abstract

Shale gas has gained importance in the energy landscape in recent decades. However, its development has raised environmental concerns, especially, those associated with water management. Thus, the assessment of water management aspects which inevitably impact the economic aspects, is crucial in evaluating the merits of any project exploiting this energy source. This paper provides a review of the economic and environmental implications of shale gas development around the world. Furthermore, to demonstrate the interplay between the various technical, environmental and economic factors in concrete terms, we report on a specific set of case studies conducted using an integrated decisionsupport tool that has been implemented to model and optimize shale gas development projects. The case study results confirm that the gas breakeven price decreases with expansion in scale of the shale gas development, i.e. increasing the number of well-pads in the system. However, scale also increases the options for water re-use and recycle in drilling and fracturing operations, which can result in lower freshwater withdrawal intensity. Moreover, under water scarcity scenarios, the choice of well-pad designs that are 2 inherently less water intensive was found to be more cost-effective than water re-use or/and recycle strategies at reducing net freshwater demand. Similar trends were observed when the impact of wastewater quality, i.e. total dissolved solids concentration, on the optimal development strategy of shale gas plays was investigated. The results of these case studies reveal that greater efforts are needed at characterizing freshwater availability and wastewater quality for the evaluation of both the economic and environmental aspects of shale gas development.

South Africa After Paris—Fracking Its Way to the NDCs?

“…Approximately 75% of South Africa's shale resources are located in arid areas or regions with high water stress, where already today water resources are barely sufficient to meet demand as potable surface-and groundwater resources are seriously constrained. Therefore, it is questionable if capacity to supply the large amounts of water required for industrial scale shale gas fracking exists (Reig et al, 2014;Hobbs et al, 2016;Calderón et al, 2018). However, further geoscientific analyses and data are required in order to assess to what extent this water scarcity might limit or even prevent economic shale gas production (Hobbs et al, 2016).…”

Nexus Thinking at River Basin Scale: Food, Water and Welfare

“…Other approaches also incorporate ecosystem [44] or environment [28,45] as key elements due to their responsibility for water, energy, and food production and their association with ecosystem services. TPAs have not always been explicit in incorporating the economic dimension (as in Calderon et al [46]); the economic dimension has been considered in Nexus methods through integrated models or economic tools [26]. However, modeling methods with new perspectives or flexibility that expands our understanding of the trade-offs and their economic dimensions are still needed.…”

Integrated shale gas supply chain design and water management under uncertainty

“…The main aspects and decision elements associated with the deterministic planning framework for integrated shale gas and water supply chains, developed by the authors, are presented in Table . This planning framework was used to address a variety of case studies, including the analysis of the mathematical formulation of water quality constraints as well as the water‐energy‐economics nexus associated with the development of shale gas resources in Colombia . The reader is referred to the original publication of the planning framework for more details regarding the mathematical formulation and application of the deterministic framework, for example, detailed definition of the model parameters, variables, and constraints.…”

“…Moreover, the effect of economies of scale in light of uncertainty was also investigated. For this purpose, the previous case study (6 well‐pads case) was extended to accommodate two additional well‐pads (8 well‐pads case study). However, due to the complexity of the resulting optimization model, the convergence of the model presented extensive running times and low‐quality solutions.…”