The implementation of fusion properties calculation to predict wax deposition

Abstract

Deposition of wax on the pipe walls is one of the complex flow assurance problems that causes a decrease and complete blockage of oil production rates by reducing the cross-sectional area of flow in the pipelines. In addition, surface facilities require higher energy consumption and failure of facilities due to wax plugging. Effective design of oil recovery processes requires an adequate prediction of the thermodynamic conditions in which wax can precipitate from crude oil, depending on the pressure, temperature, and composition of the oil. In this paper, the modified melting and pour point temperatures were presented based on the fluid description. Other fusion properties such as the enthalpy of fusion, the solid-state transition enthalpies, and the heat capacity of fusion have been calculated to modify the multi-solid model for predicting wax deposition. The proposed modified equations for melting and pour point temperatures were showing reliable agreement with experimental data based on SARA analysis and demonstrated more accurate results compare to literature data. In order to justify the proposed model, the comparative approach has been implemented between literature, experimental, and data obtained based on proposed solutions. The detailed description of the Republic of Kazakhstan’s (RoK) oil fields, components from C1 up to C36+ has been used during this research and the most crucial components which tend to form wax precipitation from C15H32 to C20H42 were plotted, which showed an increasing accuracy of 11 % for melting point temperature and 7 % for pour point temperature compared to literature data. As a result, the proposed modified solutions for fusion properties demonstrated good agreement with literature and obtained results of modifications can be used for further research on Multi solid model of wax precipitation