A method for electrically enhancing oil-recovery from an underground oil-bearing reservoir, comprising: a. selecting an underground rock formation comprising an oil-bearing reservoir; b. positioning two or more electrically conductive elements (4,5) at two or more spaced apart locations in proximity to said formation (2,3), at least one of said conductive elements (4,5) being disposed in or adjacent to a borehole affording fluid communication between the interior of said borehole and said formation; c. causing a capacitive charging of said formation either by: i. imposing a controlled electrical charging potential between said two or more electrically conductive elements (4,5) for a charging time sufficient to cause said capacitive charging of said formation to an operating charging potential; or ii. passing a controlled amount of electric current along an electrically conductive path through said formation, said electric current being produced by a DC source, at a charging potential; characterized in that: capacitive charging of said oil-bearing underground rock reservoir is done using a capacitor charging pump having feedback means for providing a capacitive charging; which capacitor charging pump having feedback means is adapted to provide and maintain a charging current either in the form of a direct current, a direct current overlaid with an AC current, or as an alternating current, between two or more electrically conductive elements (4,5) positioned at two or more spaced apart locations in proximity to said reservoir; and wherein said method further comprises: d. lowering or maintaining said charging or operating charging potential below 40 mV per running meter between said two or more electrically conductive elements (4,5); and e. withdrawing oil from at least one of said boreholes. a. selecting an underground rock formation comprising an oil-bearing reservoir; b. positioning two or more electrically conductive elements (4,5) at two or more spaced apart locations in proximity to said formation (2,3), at least one of said conductive elements (4,5) being disposed in or adjacent to a borehole affording fluid communication between the interior of said borehole and said formation; c. causing a capacitive charging of said formation either by: i. imposing a controlled electrical charging potential between said two or more electrically conductive elements (4,5) for a charging time sufficient to cause said capacitive charging of said formation to an operating charging potential; or ii. passing a controlled amount of electric current along an electrically conductive path through said formation, said electric current being produced by a DC source, at a charging potential; i. imposing a controlled electrical charging potential between said two or more electrically conductive elements (4,5) for a charging time sufficient to cause said capacitive charging of said formation to an operating charging potential; or ii. passing a controlled amount of electric current along an electrically conductive path through said formation, said electric current being produced by a DC source, at a charging potential; d. lowering or maintaining said charging or operating charging potential below 40 mV per running meter between said two or more electrically conductive elements (4,5); and e. withdrawing oil from at least one of said boreholes.