Simulação do escoamento monofásico em um estágio de uma bomba centrífuga utilizando técnicas de fluidodinâmica computacional

摘要

Oil production and exploration techniques have evolved in the last decades in order toincrease fluid flows and optimize how the required equipment are used. The base functioningof Electric Submersible Pumping (ESP) lift method is the use of an electric downhole motorto move a centrifugal pump and transport the fluids to the surface. The Electric SubmersiblePumping is an option that has been gaining ground among the methods of Artificial Lift dueto the ability to handle a large flow of liquid in onshore and offshore environments. Theperformance of a well equipped with ESP systems is intrinsically related to the centrifugalpump operation. It is the pump that has the function to turn the motor power into Head. In thispresent work, a computer model to analyze the three-dimensional flow in a centrifugal pumpused in Electric Submersible Pumping has been developed. Through the commercial program,ANSYS® CFX®, initially using water as fluid flow, the geometry and simulation parametershave been defined in order to obtain an approximation of what occurs inside the channels ofthe impeller and diffuser pump in terms of flow. Three different geometry conditions wereinitially tested to determine which is most suitable to solving the problem. After choosing themost appropriate geometry, three mesh conditions were analyzed and the obtained valueswere compared to the experimental characteristic curve of Head provided by themanufacturer. The results have approached the experimental curve, the simulation time andthe model convergence were satisfactory if it is considered that the studied problem involvesnumerical analysis. After the tests with water, oil was used in the simulations. The resultswere compared to a methodology used in the petroleum industry to correct viscosity. Ingeneral, for models with water and oil, the results with single-phase fluids were coherent withthe experimental curves and, through three-dimensional computer models, they are apreliminary evaluation for the analysis of the two-phase flow inside the channels ofcentrifugal pump used in ESP systems