TY - JOUR
TI - Study on the melting characteristics of bow-shaped wall-bound gelled crude oil mixed with hot water in gathering and transportation systems
AU - Liu Xiaoyan
AU - Hou Jingjing
AU - Ma Chuan
AU - Xu Ying
JN - Thermal Science
PY - 2026
VL - 30
IS - 1
SP - 467
EP - 481
PT - Article
AB - Waxy crude oil at the wellhead typically has a temperature below its pour point, leading to the accumulation of gelled crude oil on pipeline walls, causing block-ages. The melting behavior of gelled crude oil in hot water is critical for pipeline safety and efficiency. This paper presents a numerical simulation of the phase-change heat transfer process of bow-shaped gelled crude oil blocks with hot water injection along the inner pipe wall. The melting and flow characteristics of the gelled crude oil are analyzed, and the effects of water temperature, initial oil temperature and oil thickness on the melting process are discussed. The results indicate that the melting rate of gelled crude oil is relatively fast before the liquid phase fraction reaches 55%, while the melting rate slows down for the remaining 45%. Increasing the water temperature, the initial oil temperature, and reducing the oil thickness can accelerate the melting process of the oil block. However, their effects on shortening the melting time of the oil block exhibit a non-linear relationship. During the flow process, the melted crude oil undergoes deformation, becoming “flattened and elongated” and exiting the pipeline with water in a thin, strip-like form. The lower boundary of the crude oil develops an irregular, corrugated shape. Additionally, an increase in crude oil thickness leads to the formation of small droplets. These findings provide valuable insights for improving the safety and efficiency of crude oil gathering and transportation, as well as enhancing energy savings in practical engineering applications. 
DO - 10.2298/TSCI241003001L
ER -