Investigação numérica da influência da altura do leito de partículas no escoamento em poços horizontais

Abstract

The oil and gas industry faces significant challenges in the safe abandonment of wells, particularly in offshore environments, where effective sealing is crucial to prevent leaks and environmental contamination. This work presents a two-dimensional numerical investigation into the influence of particle bed height on fluid flow in horizontal wells during abandonment operations. Using computational fluid dynamics (CFD) simulations via the Star-CCM+® software, the study analyzes fluid behavior in circular pipes with different partial obstruction configurations (y = R, y = R/2, and y = R/4). The numerical modeling employs the finite volume method to solve the mass and momentum balance equations, with a structured mesh and specific refinement in regions near the walls. Boundary conditions include uniform velocity at the inlet, atmospheric pressure at the outlet, a no-slip condition at the walls, and different power law índices (n = 0,1, n = 0,5, and n = 1). As a reference point for the analysis, the theoretical solution of the Poiseuille number (Po = 16) in an unobstructed circular pipe is used. The investigation focuses on the systematic comparison of the Poiseuille number, friction factor, and pressure drop between the obstructed cases and this reference case, establishing correlations between the bed geometry, the fluid’s rheological behavior, and the hydrodynamic parameters of the flow. The results indicate a significant increase in pressure drop and Poiseuille number with the increase in obstruction height, especially for pseudoplastic fluids (n < 1). Even in the unobstructed case, the obtained Po value remained above the theoretical one (Po = 16), which is attributed to the imposed boundary conditions and the numerical effects inherent to the discretization.