| 摘要 |
The present invention is directed to a method and apparatus for determining that a drillstring in a wellbore is susceptible to sticking against a wellbore surface. When characterized as a method, the method steps include (1) monitoring a vibration characteristic of the drillstring during drilling operations, and (2) comparing the vibration characteristic with at least one prior vibration characteristic to identify impending sticking. In the preferred embodiment, vibration amplitude is monitored to detect amplitude diminishment which is indicative of impending pipe sticking. Preferably, vibration data is subjected to a stabilizing signal processing operation which minimizes the adverse impact of noise and normalizes the data to facilitate comparison with prior time periods. Preferably, the data is presented and displayed in a time-domain format to allow visual comparison over a selected time interval. |
