Thermodynamic Modeling for Determining Wax Appearance Temperature (WAT) of a Given Petroleum Mixture

Nkeiru Johnson Achilike; Felicia Chukwu; Godwin Chukwu

Nkeiru Johnson Achilike African Center of Excellence, Institute of Petroleum Studies, University of Port-Harcourt, Rivers State, Nigeria.
Felicia Chukwu Toncia Energy Consulting and Professional Services Ltd, Abuja, Nigeria.
Godwin Chukwu Toncia Energy Consulting and Professional Services Ltd, Abuja, Nigeria.

Abstract

Wax is a natural constituent of petroleum fluids that changes the fluid state from liquid to solid phase when the appropriate temperature and composition conditions exist during production, transportation and storage of the petroleum fluid. Wax Appearance Temperature (WAT) is that temperature at which wax particles start to precipitate out of a petroleum mixture. The WAT of a petroleum fluid can be measured experimentally or calculated using thermodynamic models. The use of thermodynamic model reduces the cumbersome task of collecting samples and running experiments which could be expensive. Thermodynamic models are used to simulate wax precipitation at different temperature, pressure and composition conditions. Developing or modifying such models could be a tiresome and frustrating task when full knowledge of the process is not available. This article will serve as a quick guide for providing a step by step procedure for obtaining WAT from developed thermodynamic model. The approach presented in this article is unique because it is a straight-forward method for determining WAT. It provides the ease of modifying the WAT model at any stage of the procedure.

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