Modeling and analysis of mud filtrate invasion using Computational Fluid Dynamics

Abstract

In spite of continued improvements in logging technology, mud-filtrate invasion and related formation damage due to drilling fluids can result in misinterpreted values of rock and fluid properties in the reservoir. Well planning with accurate information of target reservoir will optimize drilling operation, completion and maximize production of oil and gas. In this study, the dynamics filtration process into the gas and oil bearing reservoir are studied in vertical open hole system using computational fluid dynamics (CFD) module of the commercial software COMSOL. This study investigates the communication between the fluids and formations during drilling with special emphasis on effect of formation porosity, permeability, time, overbalanced pressure. The results provided an insight in the formation damage around wellbore and related reduction in hydrocarbons flow due to altered fluid saturation. The CFD simulation results of fluid saturation profile have, been validated against published correlations which showed good agreement. This enabled the process of predicting the influence of various parameters on the invasion process. This simulation study will enable accurate prediction of damaged zone around the wellbore which will benefit different operations such as drilling fluid design, log interpretation, hydraulic fracturing and well completion.