and captive groundwater to be electrically conductive an electroconductive fluid may be injected into the formation through one or both boreholes to maintain an electroconductive path between the electrodes 15 16 referring to fig2 a pipe 40 in borehole 14 delivers electrolyte solution from the ground surface to the underground formation 11 preferably a pump 43 is used to convey the solution from a supply 44 and through a control valve 45 into borehole 14 borehole 14 is preferably equipped with conventional flow and level control devices so as to control the volume of electrolyte solution introduced to the borehole a detailed system and procedure for injecting electrolyte solution into a formation is described in the aforementioned u s pat no 3 782 465 see also u s pat no 5 074 986 the entire disclosure of which is incorporated by reference herein referring now to fig1 2 the steps for practicing the improved method for stimulating oil recovery will now be described an electric potential is applied to first electrode 15 so as to raise its voltage with respect to the second electrode 16 and region 17 of the formation 11 where the producing well 13 is located the voltage between the electrodes 15 16 is preferably no less than 0 4 v per meter of electrode.