Risk identification and risk management in pumping of gel fluids in pipeline applications

Abstract

The focus of this research work is to develop a model that will predict the pressure required to move a crosslinked gel plug in a pipeline in the hypothetical case of Halliburton Temblok 50 gel. In addition, this study seeks to carry out risk analysis on the experimental set up and procedure by using JSA and risk acceptance criteria to identify what can go wrong. This study adopts a simplified theoretical model which was initially developed from Fanning equation in order to get pressure drops range which was used in setting the PSV on 2, 4 and 6 inches pipeline. In addition, an experiment was conducted in both Halliburton and IRIS test yard by pushing 50m, 100m and 150m gel plug into 2 inches pipeline at different times. Water was then pumped into the line until the gel plug started moving and pressure recorded. The experiment was repeated for the 4 and 6 inches pipelines and their pressures recorded. The experiment was carried out based on two assumptions. First, that the flow rate, and the settling times are constant. Second, that the pipelines were smooth and that the topography in which these lines were laid was straight. The theoretical and experimental results were then compared and graph of pressure drops against pipe diameters were plotted for 50m, 100m and 150m gel plug. From these graphs, a linear equation containing pipe diameter and gel plug length as input parameter was developed. The result in this study points to a model which can be used in predicting the pressure required to set Temblok 50 gel in motion provided the gel plug length and the pipe diameter are known.