Flow assurance, simulation of wax deposition for Rawat field using PIPSIM software

Abstract

One of the most relevant flow assurance issues in oil transportation is indeed the phenomena of wax deposition. Wax deposition occurs when the temperature along the pipeline falls below a point where it is described as Wax Appearance Temperature (WAT) The deposition may cause a lot of problems to the industry and definitely will involve expensive cause to overcome the problem. The flow system was built for Rawat field which is consists of (13) wells in the Rawat/Wateesh field. In this studies a series of cases were carried out at different flow rates, ambient temperature to study falling temperature through f pipline using PIPESIM Software and providing data from central petroleum laboratory and Rawat operating company. To check that temperature at all points along the flow line and trunk line is above the pour point and wax appearance temperature, check the requirement of heater, heat tracing and insulation for the pipelines more ever is used to studies the influence of changing flow rate, ambient temperature and water cut for pipeline temperature. The line size, line velocity and heat duty of the system have been calculated using excel program.The results show that the minimum temperature criteria for pipelines should be above 54C to avoid gelling of the fluid, Wax precipitation analysis results indicates that the minimum wax precipitation temperature for Wateesh W-was approximately 62°C and the same for Rawat RC-1 well were approximately 58°C.the flowlines size were determined 4” and 6” for trunk line.Also The results show that there is a direct relation between the wax deposition and temperature, It was observed that wax deposit increases with decreasing the temperature. On the other hand, an increase in flow rate results in a decrease in the wax deposition. Finally, hot insulation of the flow lines and trunk line was required, Electrical Heat Tracing to heat the fluid to 75 Deg, chemical injection such as wax inhibitors and pigging process to control the wax deposition.