某井Φ73 mm×5.51 mm P110油管在酸化作业过程中发生纵向开裂。通过宏观分析、化学成分分析、力学性能试验、金相分析、扫描电镜断口分析等方法，对该油管开裂原因进行了分析。结果表明：该油管在采油阶段内壁发生严重偏磨导致其壁厚严重减薄，无法承受酸化作业时的试验压力，从而在偏磨沟槽壁厚最薄处发生延性开裂。最后，提出了油管在采油时使用防偏磨器的建议。

The Φ73 mm×5.51 mm P110 tubing in a well cracked longitudinally during acidification operation. By means of macro examination, chemical composition analysis, mechanical property test, metallographic analysis and scanning electron microscope fracture analysis, the cracking reasons of the tubing were analyzed. The results show that the wall thickness of the tubing was reduced greatly because serious uneven wear happened to the inner wall during oil production, which made the tubing not withstand the test pressure of acidification operation, so ductile cracking occured at the thinnest wall thickness position of the uneven wear groove. Finally, the measure of using partial abrasion protector during oil production was proposed.