Interface profile in oildraggingwater pipeline system

Key words:  two phase flow  interface profile  water displacement  stability of oilwater interface  water plug  pipeline corrosion

Abstract:

The pipeline corrosion products due to water accumulation at low elevation spots blocking pipeline is a serious threat to the normal operation of the pipeline. The characteristics of oildraggingwater pipeline system were studied experimentally and theoretically to analyze the mechanism of water withdrawn by oil flow. Labscale experiments were conducted on the test loop with inner diameter of 27 mm to measure water displacement and the critical oil flow rate required for the onset of water displacement by diesel flow from a lower horizontal test section into an upward inclined test section. In addition, a model for predicting the oilwater interface profile, which is based on combining momentum equations of two phases with the neutral stability condition of stratified flow, was received. The predicted amount of water withdrawn by diesel flow and the critical oil flow rate were favorably compared with the experimental measurements. The results indicate that the new model can predict the changes in two parameters. The water height gradient model can predict the distribution of the phase interface in oildraggingwater pipeline system with oil flow in laminar.