Abstract: A slurry for enhancing geothermal recovery in a subterranean heat reservoir comprises thermal particles and a carrier fluid. The thermal particles have a selected volume, composition and physical properties sufficient to form a thermal pathway in the reservoir with a particle pack thermal conductivity that meets or exceeds a target thermal conductivity at a thermal pathway stress load of the reservoir. The carrier fluid has a selected fluid volume and viscosity sufficient for the slurry to be injected into openings of the reservoir at an injection pressure higher than the reservoir stress value.