| 摘要 |
The depth at which a string of pipe is stuck in a well borehole is determined using a tool suspended by a logging cable (22) and comprising a tool body (18) for running in the stuck well string, the body enclosing a first electromagnetic coil (50) connected with a suitable storage capacitor (38) and switch (36) for forming a strong magnetic field at a specified depth on the stuck well string. A second electromagnetic coil (48) is included in the tool and functions as a detector means. The detected signal is output to a suitable amplifier system and a recorder (34). Upon application of stress to the well string, the amplitude of magnetic marks above the stuck location will either be reduced or substantially erased; the electromagnetic marks below the stuck points will not be reduced, and the change in detected signals by the detector means indicates the location of the well string sticking and enables location of a free point in the string. |
