The impact of initial oil saturation and presence of fractures on hole stability has been analyzed using a three-dimensional, fully-coupled multi-phase finite element model. The model accounts for thermo-hydro-mechanical coupling as well as solubility of gas in oil and evaporation of oil into gas in both the rock matrix and fractures. In addition, the viscosities of the oil and gas phases, formation volume factors for oil and gas, gas-oil solubility ratio, oil volatility ratio and the saturations are assumed to be dependent on the temperature. The model is verified with analytical solutions for the limiting case of a medium saturated with a single fluid. A parametric study is carried out varying the initial oil saturation and fracture parameters and the changes to the stress state around the wellbore are assessed. A preliminary analysis of failure study shows that the presence of fractures and lower initial oil saturation increases the failure potential.

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