Experimental Study of Wax Deposition in Pipeline – Effect of Inhibitor and Spiral Flow

Abstract Wax deposition is one of the main flow assurance problems in the oil industry. It can result in the restriction of crude oil flow in the pipeline, creating pressure abnormalities and causing an artificial blockage leading to a reduction or interruption in the production. Wax can precipitate as a solid phase on the pipe wall when its temperature (inlet coolant temperature) drops below the Wax Appearance Temperature (WAT). An experimental flow loop system was built in the lab to study the variation of wax deposition thickness under the single phase transport. A series of experiments were carried out at different flow rates (2.7 and 4.8 L/min) to study wax deposition and measure the wax thickness using four different techniques including direct technique (pigging method), pressure drop technique, heat transfer technique, liquid displacement-level detection technique (LD-LD). The effect of factors on wax formation such as inlet coolant temperature, pressure drop, flow rates, time, inhibitor and spiral flow have been examined. The results shows the wax inhibition percentage (WI) % of inhibitor W802 (polyacrylate polymer (C16-C22)) and spiral flow at flow rate 2.7 L/min, inlet coolant temperature14 ºC, was 40% while with the spiral flow was 65%. At flow rate 4.8 L/min, inlet coolant temperature 14 ºC and 1000ppm inhibitor W802, the wax inhibition percentage was 45% while with the spiral flow was 73%. This percentage of inhibition will increased rapidly by increasing the the inlet coolant temperature. Keywords: Wax inhibitor, spiral flow, wax inhibition, wax measuring techniques