Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Displacement flows of miscible fluids through axisymmetric expansion-contractions
Submission Author:
Rafael Menezes de Oliveira , RJ , Brazil
Co-Authors:
FREDERICO CARVALHO, Rafael Menezes de Oliveira
Presenter: Rafael Menezes de Oliveira
doi://10.26678/ABCM.COBEM2023.COB2023-0926
Abstract
One critical step during an oil well construction is the primary cementing process. Classified as "the process of placing cement in the annulus between the casing and the formation exposed to the wellbore" (Nelson, 1990), the cementing operation provides zonal isolation, protects the casing from corrosion, and adds mechanical stability to the well. In this process, during the drilling stage, cross-sectional irregularities may appear on the open hole section due to poorly consolidated formation rocks. Such irregularities can be described as washouts. As a result, the placement of cement slurry occurs through a displacement process in an irregular annular space. Motivated by this industrial process, the current work employs Direct Numerical Simulation to investigate the displacement process between two miscible Newtonian fluids in an annular space containing an abrupt expansion followed by a contraction on the external radius. The axisymmetric Navier-Stokes equations in cylindrical coordinates are solved coupled with a convection-diffusion equation for a scalar that measures the concentration of the displaced fluid. For neutrally buoyant flows, fixed values of the viscosity ratio and fixed size of the rectangular washout, we investigate how the influence of different values of the injection rate (captured by the Reynolds number), and different values of the miscibility of the interface (captured by the Péclet number) affect displacement efficiency. Our results provide efficiency values close to 100%. These values motivate further investigations of miscibility to improve displacement efficiency in the industrial setting.
Keywords
displacement efficiency, Miscible Fluids, Annular flow, Cementing
