Experimental and theoretical study on wax deposition and the application on a heat insulated crude oil pipeline in Northeast China

An experimental loop apparatus of heat insulated waxy crude oil pipeline was established to study the wax deposition behaviors. The effects of flow rate and ambient temperature on the thickness and wax content of deposition layer were investigated. A kinetic calculation model for the thickness and wax content of deposition layer in heat insulated crude oil pipeline was established based on the principle of molecular diffusion, aging and shear energy. The results calculated by the model are in good agreement with the experimental values. The wax deposition thickness of a heat insulated crude oil pipeline in different seasons and operation time in Northeast China was predicted according to the theoretical model, which was anticipated that can provide a scientific basis for formulating the wax removal cycle of the pipeline. The predicted results showed that the thickness of the wax deposition layer increases first and then decreases along the pipeline.