Abstract: An electrical heating system for enhancing production from an oil well, particularly an oil well of the kind commonly known as a horizontal well, the well including an initial well bore extending downwardly from the surface of the earth through one or more overburden formations and communicating with a producing well bore extending from the initial well bore into at least one oil producing formation. The producing well bore may or may not be truly horizontal The heating system includes an electrode array comprising a plurality of at least three tubular, electrically conductive heating electrodes extending through the producing well bore. Each electrode has a given length, usually two to three meters, and a smaller diameter D. The sum of the electrode lengths is substantially less than the length of the producing well bore. The electrodes are spaced from each other by isolation sections; the length of an isolation section is much greater than the electrode diameter D.

Abstract: A control for an electrical heating system that enhances production from an oil well, particularly a horizontal oil well; the well includes an initial well bore extending downwardly from the surface of the earth through one or more overburden formations and into communication with a producing well bore that extends or deviates outwardly from the initial well bore into an oil producing formation. The heating system includes an array of short, electrically conductive heating electrodes extending longitudinally through the producing well bore. The heating system further includes apparatus for electrically energizing electrodes that are close to each other with A.C. power; the A.C. power supplied to electrodes near each other has a phase displacement of at least 90.degree., usually 120.degree. or 180.degree., between electrodes.