Analysis on Longitudinal Crack of Tubing in One HTHP Gas Well
The tubing longitudinal crack failure accident occurred in a HTHP gas well.In order to determine the cause of the longitudinal crack failure of tubing,the NDT and physical and chemical tests were carried out on the tubing sampled at different depths of the well com-pletion pipe string.It was found by the NDT results that there are longitudinal cracks on the outer surface of the coupling and pipe body of the tubing.It was shown per the physical and chemical tests that the cracks on the surface of the tubing are the stress corrosion and corro-sion fatigue cracks,and the cause of the cracks is related to the environmental medium and the stress conditions of the completion pipe string.By analyzing and calculating the stress conditions of the completion pipe string,it was considered that the direction of the tubing crack is related to the alternate internal pressure load born on the pipe string.It was suggested to use the extension tube in the design of well completion string,and use the completion fluid matching with the S13Cr110 tubing to prevent tubing cracks in HTHP gas well.
万方数据
维普
