Abstract
Fluid losses are still today one of the most challenging problems in well construction. Most strategies to control losses are empirical and in some situations, detrimental effects can not be avoided. This article deals with unique modeling efforts to understand the dynamics of bridging fractured zones. The main tools adopted to address the problem were the Computational Fluid Dynamics, whenever necessary coupled with Discrete Element Method packages. The main goal was to study particle deposition inside fractures due to losses through the external walls of an axial annular flow. ANSYS FLUENT® and EDEM® were the adopted simulation tools.
The study includes two different modeling strategies: Discrete Element Simulation and Granular Eulerian CFD approach. The first method solves the particle trajectory equations individually, considering collision and cohesion effects. Despite of the reliability of the approach, computation effort is huge and limits the number of particles in the system. The Eulerian approach, on the other hand treats statistically the particulate system, generating a probabilistic field of occurring one or the other phase at given space and time. This approach obviously generates smaller computational costs. The developed methodologies allow the evaluation of the efficacy of bridging agents in plugging fractured zones.
