One of the greatest challenges of Enhanced Geothermal Systems (EGS) is fracture control and flow control in the subsurface. Fracture control comprises of efficiently manipulating natural fractures and stimulating new fractures to desired specifications. Flow control comprises of optimizing fluid flow to and between wells for improved energy recovery. In this study, we investigate the potential of using multi-spot well layouts as a means for fracture control and flow control. A central well serves as a stimulation and injection well while a surrounding set of production wells serve as a ‘fracture cage’. All wells are drilled prior to any injection or hydraulic stimulation with the intent of using the ‘fracture cage’ to (1) limit out-of-zone fracture growth, (2) to maximize the probability of a hydraulic connection between the injector and one or more production wells, and (3) to recover more of the injected fluids. Statistical analysis is used to evaluate the performance of several multi-spot well layouts in different stress and fracture regimes. Numerical modelling with GEOS predicts that the presence of the production wells can stunt or even halt the propagation of hydraulic fractures. This research was conducted for the design phase of the SIGMA-V geothermal project at the Sanford Underground Research Facility (SURF).

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