Abstract: In order to solve the problem that the corrosion of the offshore oil and gas pipeline is accelerated by the damage to the outer surface, the paper was aimed at building a modified empennage residual error GM(1,1) model based on the traditional gray model to predict the residual life of pipelines. Firstly, a gray differential equation was established after testing the smoothness and quasi-exponential regularity of pipeline corrosion depth data are tested. Secondly, a complete modified gray model of submarine pipeline corrosion was obtained by calculating the gray differential equation parameters with a least square method and correcting the residual error through predicting the corrosion depth. The model was used to predict the remaining life of a certain test submarine pipeline section as an example. The results show that the relative error of gray model prediction is 36.7% and that of forecasting GM (1,1) is 3.79%, so the prediction accuracy is higher and the life prediction is more reasonable.

Key words: submarine pipeline, modified empennage residual error GM(1,1) model, falling object risk, corrosion, remaining life prediction