This project intends to develop an improved wellbore stability model based on poromechanics and non-equilibrium thermodynamics which describes the physico-chemical interactions between a multi-component drilling fluid and a reactive shale formation. Through finite element modelling, this model can be employed in wellbore stability studies in order to optimise drilling fluid formulation and mud weight selection. Specifically, we present the results of finite-element-finite colume based analysis of thermal and solute diffusion associated with wellbore heating and cooling effect on the reservoir system by drilling fluid over a period of time. Then, we solve the heat driven solute diffusion equation with thermal osmosis and solute diffusion coefficients.
This preliminary investigation indicates a gradual but steady increase in temperature in the near wellbore region during during heat energy disspation from the far-field region. A reverse process was observed during the cooling process with both indicating a constant solute mass fraction over the time limit