(681e) Incorporation of Sustainability and Economic Considerations in Process Control of Hydraulic Fracturing in Unconventional Reservoirs
Motivated by this consideration, in this work, we propose a new control framework that has integrated sustainability considerations into the post-fracturing process. In this regard, a dynamic model is developed to describe the flow rate and the concentration of total dissolved solids (TDS) in flowback water from fractured wells, provided that the amount of water injected into the fracture well is known. Then, a thermal membrane distillation (TMD) unit is considered for the removal of TDS. A multiobjective optimization problem is formulated to determine the amount of water to be injected by considering the entire superstructure that consists of hydraulic fracturing, storage, transportation, and water treatment, maximizing annualized profit from recovered water per period while minimizing the water footprint of the process through Pareto optimal solution. The obtained water amount will be included in a model-based pumping schedule design technique to compute the optimal pumping schedule during a hydraulic fracturing process that will regulate the distribution of proppant bank height and suspended proppant concentration ; this flow may not be sufficient to achieve the desired fracture length, which will lower the productivity of the produced well, however, it will maximize the annualized profit of the entire superstructure as well as reduce environmental impact.
 Siddhamshetty, P., Kwon, J.S., Liu, S., Valkó, P. (2017), Feedback control of proppant bank heights during hydraulic fracturing for enhanced productivity in shale formations. AIChE J., 64, 138-147.
Elsayed, N. A., Barrufet, M. A., Eljack, F. T., El-Halwagi, M. M. (2015). Optimal design of thermal membrane distillation systems for the treatment of shale gas flowback water. Int. J. Membr. Sci. Technol., 2, 1-9.