Experimental Study on the Clamping Performance of Worn Snubbing Unit Slips

The height of the slip teeth directly affects the gripping efficiency of Snubbing Units. However, there is currently a lack of experimental methods for quantitatively assessing the height of worn slip teeth and their gripping capability. Therefore, a die-cutting inspection method was adopted to measure worn slip heights quantitatively. An experimental platform was developed to simulate the actual loading conditions of Snubbing Units during pipe-to-pipe gripping. Using image processing techniques based on pressure-sensitive paper color changes and grayscale values, experiments were conducted to evaluate the pipe-gripping performance of slips with varying wear heights under simulated operational conditions. By applying the least squares method to fit the functional relationship between the characteristic parameters of worn slip jaw height and the radial slip jaw gripping force/sliding friction coefficient, a predictive model was established for the variation in gripping performance of worn slip jaws with their height. Consequently, a testing and evaluation methodology for the gripping performance of worn slips in Snubbing Units has been established, providing a methodological framework for assessing the gripping capability of worn slips in Snubbing Units.