Corrosion Perforation Reason of a Blind Tube in Shengli Oilfield

The macroscopic morphology, composition and phase composition of corrosion products of a failed blind tube in Shengli oilfield were observed and analyzed by direct reading spectrometer, metallographic microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Combined with the service condition of the blind tube, the corrosion and perforation causes of the blind tube were studied. The results showed that CO₂ corrosion mainly occurred in the blind tube. Besides, as the blind tube section was in the perforating range, corrosion products were easily damaged and fallen off by fluid, which caused localized corrosion and corrosion perforation finally.