Wax deposition analysis for oil and gas multiphase flow in pipelines

Student thesis: Master thesis (including HD thesis)

  • Fernando Raul Montero Revelo
4. term, Oil and Gas Technology, Master (Master Programme)
Wax deposition has been a big challenge for the Oil & Gas industry, and the current energy demand has driven the oil production to remote environments where subsea facilities present low-temperature environments that represent potential financial losses due to wax deposition. Some techniques have been developed to deal with wax formation or deposition problems; however, its modeling and simulation present some limitations related to accurate predictions of wax deposit thickness and location. The closed interrelation of wax deposition process with aspects referring to thermodynamics, heat & mass transfer and fluid mechanics brings additional complexity to wax deposition analysis. This work consists in a comparative study of modeling and simulation of a subsea horizontal pipeline section transporting a multiphase flow. The analysis is done using a commercial software and a self developed code, which are used to evaluate the prediction of wax deposition using a non-compositional model; always pursuing a better understanding of the wax deposition process, multiphase flow, transport phenomena, and their mathematical models and simulation tools. Four main cases of analysis are considered in this project in which different gas and liquid mass flow rates are evaluated. Moreover, these four cases are expanded to 16 study cases to include different paraffin characterization and deposition times into the wax deposition analysis. Experimental data available in open literature is used for fluid characterization in both commercial simulator and self developed code. The results demonstrate the high sensitivity of the wax deposition prediction to the accuracy of the calculation of the inner wall temperature as well as the influence of the thermodynamic approach used in the wax formation analysis. The wax deposition process is modeled based on the non-compositional Matzain Model through the commercial software OLGA (by Schlumberger) and a code developed in Matlab.
Publication date2020
Number of pages82
ID: 333980777