Prediction of corrosion rate of oil storage tank based on non-equidistant Grey model GM (1, 1)

Vertical atmospheric steel storage tanks are important equipments in oilfield. During daily operation, corrosion defects such as perforation and fracture are often not detected in time due to the cost and difficulty in inspecting storage tanks. This compromises the safety in petrochemical plants as measures are usually not taken. The key lies in obtaining the principle of corrosion, and predicating and assessing the corrosion condition of the storage tank. However, the principle of the corrosion is very complex and the corrosion rate is affected by numerous factors. It is therefore difficult to obtain the corrosion rate accurately. This paper assessed the precision of an improved non-equidistance GM (1, 1) model, which has been set up to predict the corrosion rate of oil storage tanks. The results show that the precision of the prediction model is high and the corrosion rate evaluated via this model reconciles with the corrosion characteristic of the storage tank and can offer consults to maintenances of the storage tank.