Hydrothermal Numerical Simulation of Injection Operations at United Downs, Cornwall, UK

The United Downs Deep Geothermal Project (UDDGP) is designed to utilize a presumably permeable steep dipping fault damage zone (constituting the hydrothermal reservoir in very low permeability granitic host rock) for fluid circulation and heat extraction between an injection well at 2.2 km depth (UD?2) production 5 (UD?1). Soft hydraulic stimulation was performed increase of reservoir. Numerical simulations are analyze results evaluate Experimental field data used characterize initial static model. highly fractured, two distinct fracture networks constitute equivalent porous matrix zone, respectively. Based on experimental data, stochastic discrete (DFN) developed mimic behavior. Due large number fractures involved model, fields calculated create model which computationally feasible. Hydraulic test from UD?1 modify based observed difference real fractured DFN Additional UD?2 validate this modified permeability. Results reveal that derived observations made good representation actual overall permeability, it useful future studies. numerical simulation show amount changes due soft operation. validated field, different flow rate scenarios petrothermal doublet their respective pressure evolution examined. Higher rates have strong impact evolution. Simulations acidized enhanced region make connection ongoing laboratory works acid response possible acidizing stimulation.