Chaban N. Improvement of method for drill pipes and tubing technical condition assessment

The dissertation is aimed at improving the methods for assessing the actual technical condition of drill pipes and tubing material by examining new informative features of the pipe material, which can be used to detect defects in the pipe material at the microstructural level, and allow residual life predicting according to the results received. The presence and nature of the relationship between the images parameters of acoustic structural noise and the yield strength of the material is established. A new method has been developed for monitoring the physical and mechanical characteristics using the ultrasonic flaw detectors with piezoelectric transducers with phased arrays, which makes it possible to determine the actual values of metal pipes PMC by nondestructive methods. The method for determining the physical and mechanical characteristics, namely, taking into account the parameters of structural noises’ acoustic images and hardness, that differs from the existing one using an additional informative parameter characterizing the changes at the microstructural level, and this allows to determine the physical and mechanical characteristics with greater accuracy. A methodology for determining the actual technical condition was developed and tested in industrial conditions on tubing, and their residual life was determined on the basis of these data.