Wax precipitation is one of the most important flow assurance problems, and a significant economic issue in the petroleum industry. Wax leading to increase fluid viscosity causing the blockage of filters, valves and even pipelines, increasing pumping costs, and reducing or even stopping oil production or transport. Wax can precipitate as a solid phase on the pipe wall when its temperature drops below the Wax Appearance Temperature (WAT).
The objective of this study is using spiral flow to mitigate wax deposition. 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 process and measure the wax thickness. The effects of factors on wax formation, such as spiral flow, inlet coolant temperature, temperature drop, flow rates and experimental time have been examined.
The spiral flow created inside the pipe by inserting a twisted metal along the pipe, which will create high shear stress affecting to wax deposition. The results show that the wax inhibition (reduction) percentage (WI) % by using the spiral flow at flow rate 2.7 L/min, inlet coolant temperature14 °C, was 65%. At flow rate 4.8 L/min, inlet coolant temperature 14 °C the wax inhibition percentage was 73%. Experimentally, it was found that the spiral flow more efficient than the chemical inhibitors. This percentage of reduction will increase rapidly by increasing the inlet coolant temperature and decreased by reducing the inlet coolant temperature.
This technique of creating spiral flow inside the test section of the pipe will provide a step forward in flow assurance technology to mitigate the deposition of wax.