Corrosion Failure Analysis and Corrosion Prevention Practice Of Water Injection Pipeline In Middle East Carbonate Oilfield

摘要

In order to build up formation pressure and maintain oil production, a carbonate oilfield in the Middle East adopted water injection technology, then in less than two years, a number of corrosion perforation failures were seen in the water injection pipeline. In this paper, several methods are used to find out the pipeline failure mechanism, such as the corrosion simulation experiment, bacteria testing, scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The results show that the composition of corrosion products was FeS, Fe_3O_4, FeCO_3 and CaCO_3, which created the possibility of under-deposit corrosion. The localized corrosion was more serious under the condition of coexistence of 100 mg/L S~(2-) and bacteria than the condition of 100 mg/L S~(2-)in the injected water. Deposition of scale and bacteria in the injected water are the important factors for the pipelines' fast corrosion and leakage. The corrosion prevention strategies of water quality modification and HDPE lining technology were proposed and achieved obvious result.