Research progress of properties of wax deposit in waxy crude oil pipeline

Wax deposition is the most serious problem influencing the flow of waxy crude oil in pipelines. Thus, study on the properties of wax deposit is of great significance to ensure the safe operation of crude oil pipeline. So far, little research on the properties of wax deposit has been conducted, resulting in that field pigging operation has to rely on the experience. Herein, the main principles and characteristics of two testing apparatus most commonly used to study the properties of wax deposit were described, and the effect of crude oil composition and flow conditions on the properties and morphology of wax deposit were analyzed under different flow field conditions of cold finger and flow loop. Based on the status of research on the properties of wax deposit in waxy crude oil pipeline, the future research orientations were proposed to provide reference for further clarifying the properties of wax deposit in crude oil pipelines.