| 摘要 |
<p>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. The control includes plural power switches, each connected to at least one heating electrode; each power switch is conductive only up to a predetermined limit (usually a temperature limit). In one embodiment, each power switch includes a sensor responsive to the operating condition of its heating electrode. Another embodiment employs a telemeter circuit to actuate the power switches with sensors that are separate from the power switches.</p> |
