Estudo da fluidodinâmica de separadores ciclônicos no interior de poços petrolíferos através da técnica de CFD

Abstract

Controlling of sand production in oil and gas wells has been a subject of great interest of the oil industry. This process has a direct implication in increasing the costs of production and has been widely described in the literature. Several authors have reported problems due to the sand production in wells that includes: premature waste of equipment, considerable increase in the number of workover operations and the availability of rigs to attend the demand of drilling operations. In this context, this paper focus on simulating efficient separation on 32 swirl tubes geometries as downhole desander device. Firstly, a desander with two vanes was simulated using CFD techniques and compared with experimental data existing in the technical literature. After that, different designs of swirl tubes with different parameters was performed by means of fractional factorial design with two levels in order to perform a sort of most relevant factors. However, the results of the validation test did not show satisfactory results for the particle injection parameters used. Therefore, the fluid dynamic analysis and the application of the method for tangential velocity and pressure drop were performed. According to the results, it was verified that for the five geometrical factors analyzed the external diameter, the number of vaynes and the vortex finder length are the most significant. The most impact on pressure drop are the external diameter, the flow rate and the number of vanes for the pressure drop. Finally, a linear model was proposed for the pressure drop as a function of the eight parameters analyzed and the main interactions between two factors. Among the results, a 110% increase in pressure drop was observed for an increase in the inlet flow from 60 m3 /day to 116 m3 /day.