MATHEMATICAL MODELLING OF WAX DEPOSITION IN CRUDE OIL PIPELINES (COMPARATIVE STUDY)

ABSTRACT

In this research, wax deposition in different crude oil pipeline systems was studied. In oil pipelines, the main mechanism for wax appearance is the temperature change along the pipeline. A computer program was developed to simulate the wax precipitation phenomena. Temperature profile along the pipeline was determined and solid liquid equilibrium constant, wax mole fraction and wax thickness along the pipeline were calculated. This computer program was applied to different crude oil pipeline systems in Iraq (Baiji-Daura, Rumaila-Zubair-Fao and Hadttha-Rumailia). In Haditha-Rumaila crude oil pipeline system, it was observed that wax thickness after a year is approximately 0.1 mm and temperature declined from 303 K to around 300.5 K. The wax mole fraction after a year is approximately 0.2. The solid-liquid equilibrium constant for the first component around 0.228 and around 165 for the second component after a year. Similar results were observed in other crude oil pipeline systems studied.