(247m) Modeling and Control of Proppant Bank Height to Achieve Uniformity of a Hydraulic Fracturing System
With respect to applying automatic control strategies to oil and gas production, it is important to point out that the literature over the last ten years has been focused on applying MPC to the drilling process, which is known as managed pressure drilling (MPD) that enhances pressure control flexibility, efficiency, and safety of the process [2, 3]. However, applying MPC to improve the uniformity of the proppant bank height while optimizing the fracture geometry, both of which significantly affect the productivity of the treated well, has not been considered because of the following reasons: (1) limited access to real-time measurements, (2) presence of uncertainties in the measurement data, (3) time-dependent spatial domain, and (4) large computational burden when solving high-fidelity models of hydraulic fracturing systems. While some attempts to employ model-based control schemes have been made [4, 5], there are a number of unresolved fundamental as well as practical implementation issues to make MPC a truly real-time control technique.
Motivated by these considerations, we will first address the development of a first-principles model for the hydraulic fracturing process. Second, a novel numerical scheme will be developed to deal with the high computational requirement caused by coupling of multiple partial differential equations (PDEs) defined over a time-dependent (evolving) spatial domain. Third, a reduced-order model will be constructed by using these simulation results. Lastly, nonlinear MPC theory will be utilized for the design of the feedback control system that provides a foundation for the online control of proppant bank height in order to achieve uniformity at the end of the treatment, which is directly related to the overall efficiency of the operation.
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