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Two-phase turbulent flow of crude oil and sand in a choke valve is analysed in the present article using 3D computational fluid dynamics simulations. The discrete phase mathematical model is used to simulate the sand flow and its interaction with the oil flow in the system. Parametric study is done to identify the governing parameters to minimize the sand erosion in the system. The valve geometry and dimensions are taken from an industrial oil production project. The parameter considered in the present study are the percentage valve opening, flow rate of the sand and the pressure difference between the inlet and outlet pipes. The simulation results are presented to show the erosion rate variation with the valve opening, sand flow rate and the pressure difference. It is found that the erosion rate is high for small valve opening as well as large valve opening. Minimum erosion rate is found when the valve opening is between 20-30% for all the cases with various pressure differences. Locations of maximum erosion rate are predicted in the simulations.

Precipitation of heavy hydrocarbon components such as Wax and Asphaltenes are one of the most challenging issues in oil production processes. The associated complications extend from the reservoir to refineries and petrochemical plants. Precipitation is most destructive when the affected areas are hard to reach, for example the wellbore of producing wells. This work demonstrates the effect of adjusting choke valve sizes on thermodynamic parameters of fluid flowing in a vertical well. Our simulation results revealed optimum choke valve sizes that could keep producing vertical wells away from Asphaltene precipitation. The results of this study were implemented on a well in Darquin Reservoir that had been experiencing asphaltene precipitation. Experimental analysis of reservoir fluid, Asphaltene tests and thermodynamic simulations of well column were carried out and the most appropriate size of choke valve was determined. After replacing the well's original choke valve with the suggested choke valve, the Asphaltene precipitation problem diminished.