Formation Damage and Skin Factor Due to Filter Cake Formation and Fines Migration in the Near-Wellbore Region

ABSTRACT Particle invasion and fines migration are among the major factors causing formation damage. Extensive studies of formation damage in laboratory and several modeling efforts for prediction of formation damage have been reported in the literature. However, a satisfactory model to simulate the near-wellbore formation damage in field conditions is still not available. In this paper, the linear flow core-scale model presented previously by Liu and Civan is converted into a radial flow field-scale model to simulate the formation damage near wellbore regions in actual field conditions. The radial flow field-scale model utilizes the values of model parameters obtained by a model assisted analysis of the laboratory core tests to determine the temporal and spatial variation of formation damage and the associated skin factor. Simulation results indicate that the overbalance pressure of drilling fluids is an important factor for formation damage control and that the formation damage due to constant-pressure mud filtration is less severe in two-phase flow of oil and water than single-phase flow of water in the formation.