Solução numérica para sedimentação de adensantes em fluido não newtoniano

Abstract

Sedimentation of weighting materials exposes serious risks to the structural integrity of a drilling well. Therefore, a further understanding of the settling phenomenon as well as the rheological behavior of drilling fluids is essential to ensure the safety of a drilling well. Conventional solution methods like CFD-DEM are impracticable since the physical domain is enormous and the particulate system is microscopic, ranging from 10 to 200 µm. In that way, there is a demand of solution methods that can describe the whole sedimentation process, including the fluid rheology, which characterizes particle gelification, and solid-solid interaction, including particle collision and sediment compressibility. In the literature, there are records of sedimentation studies since the beginning of the last century, however the current paradigm studied to analyze sedimentation based on the Continuum mechanics was proposed only in the end of the 1970’s. This work is based on that approach and complementary theory was rescued from the literature. Results obtained here illustrate the utility of this work, which can be employed to ensure safety conditions for drilling wells by analyzing local particle agglomerations. This can only be achieved when the sedimentation dynamics are fully characterized from experimental data. The solution can also be applied to numerical studies that aim to understand the relation between the parameters from the constitutive theory and the changes in fluid rheology and suspension properties.