| 摘要 |
<p>A petroleum well (20) comprises a well casing (30), a production tubing (40), a source of time-varying current (68), a downhole tracer injection device (60), and a downhole induction choke (90). The casing (30) extends within a wellbore of the well (20). The tubing (40) extends within the casing (30). The current source (68) is located at the surface. The current source (68) is electrically connected to, and adapted to output a time-varying current into, the tubing (40) and/or the casing (30), which act as electrical conductors for providing downhole power and/or communications to the injection device (60). The injection device (60) comprises a communications and control module (80), a tracer material reservoir (82), and an electrically controllable tracer injector (84). The communications and control module (80) is electrically connected to the tubing (40) and/or the casing (30). The downhole induction choke (90) is located about a portion of the tubing (40) and/or the casing (30). The induction choke (90) is adapted to route part of the electrical current through the communications and control module (80) by creating a voltage potential between one side of the induction choke (90) and another side of the induction choke (90). The communications and control module (80) is electrically connected across the voltage potential. The well (20) can further comprise a sensor (108) or a sensor device (140) located upstream of the injection device (60) and being adapted to detect the tracer material injected into the well by the injection device. The sensor device (140) may also be downhole, and may comprise a modem (146) to send data to the surface via the tubing (40) and/or casing (30).</p> |
