Causes Analysis on Galling of Premium Thread Tubing Connections in One Well

Galling issues occurred frequently to premium thread tubing connections in one well. The galling morphology of tubing taken out from the well was inspected overall and the statistics analysis was carried out. The thread inspection and makeup and breakout test were done to unused tubing specimens from this batch. The galling causes of the tubing connections were analyzed from these aspects. The results show that the tubing performance resisting to galling was up to the standard, and the tubing galling was due to abnormal breakout operation in the well. Eventually the measures preventing the tubing connections from galling were suggested.