| 摘要 |
<p>Apparatus and methods are disclosed for controlling the operation of a rod-pumped oil well using calculated downhole performance of the subterranean pump (6). The surface load and position are measured at equal increments of time. The measured load and position values, in combination with physical parameters of the pumping system, including the size, weight, elastic properties, and length of the rod string (4), are used by one of three preferred mathematical-analysis techniques (figs 9-11) to construct a downhole dynagraph plot of load versus position over time as it exists at the subterranean pump (e.g., 110 or 111). The characteristics of the downhole dynagraph are then analyzed by one of a plurality of algorithms (figs 7 or 8) to detect pump-off or other pump problems.</p> |
