| 摘要 |
<p>A wireless coiled tubing joint locator for locating joints or collars in a production tubing string. The joint locator is adapted for running into a well on coiled tubing, and other downhole tools may be connectable to the joint locator. An electromagnetic coil assembly senses the increased mass of a pipe joint, and provides a signal to an electric circuit which generates a momentary electric output signal received by a pilot solenoid valve. The solenoid valve momentarily opens a pilot passageway which activates a piston to close a circulation port in the joint locator. This closing of the circulation point results in an increase in a surface pressure reading observable by the operator. A rupture disk is provided so that pressure cannot be applied to any downhole tool below the joint locator prematurely, and a seat sleeve is provided to prevent premature communication of fluid to the rupture disk but can be opened at any time by dropping a ball into the joint locator. The electronic circuit can be configured to provide a selected one of a plurality of time delays. A fixed test period is also provided in the circuit which delays activation of the time delay so that the joint locator may be tested before it is run into the well. The electric circuit and power supply are provided in a removable case for easy replacement and reconfiguration.</p> |
