Leak Causes of a Crude Oil Pipeline

A crude oil pipeline used in an oilfield leaked many times in short time, serious corrosion and wall thickness decrease were observed near the leak position of the failed pipe. Failed pipe was checked and analyzed by macroscopic analysis, chemical composition test, metallurgical analysis, mechanical property test, SEM analysis, XRD analysis and corrosion simulation test. The results showed that the formation water mixed in the pipeline was acidic and contained high salinity. The flow rate of fluid changed in across position and resulted in scaling in pipeline, led to serious localized corrosion caused by small anode big cathode corrosion galvanic cell reaction under scaling, thus wall thickness decreased, at last pipeline leaked due to the impact of solid particles and grit.