Modeling Erosion in Hollow Cylinder Tests: The Case of Low Pressure Under Variable Confining Stress

Abstract

Modelling the erosional behavior of rock cores in hollow cylinder tests is a formidable task because it involves coupled hydro-mechanical processes. In a recent work of the authors, we proposed semi-analytical hydro-mechanical framework for modelling erosion at laboratory scale through the hollow cylinder test. The model was based on the kinematic formulation of classic hydro-mechanical models also known as volumetric sand production models. The original formulation was constructed to include variable confining stress and flow rate conditions. In this new formulation, a power law dependency of the erosion coefficient λ with stress is incorporated to investigate its dependency on the variable external radial stress boundary condition reflected on the sand production curve. This is a significant update with respect to the previous formulation that assumed a constant sand production coefficient. Results show an improved performance with respect to experimental results. This model can be used to systematically calibrate sand production coefficients for different types of rocks.