A downhole hydraulic fracking system comprising of a downhole reservoir stimulating tool, an injector tool, and a compression tool, configured to convert compressional strain energy gained from the compression of the drilling tubulars above the tool into multiple high-pressure fluid pressure waves, that then propagates down the drill string and into the subsurface formation causing artificial cracks and fractures; resulting in enhanced rock permeability and increased production of fluids from the sub-surface formation.