Maintaining a borehole stable during the life time of the well is one of the greatest tasks encountered in the oil and gas industry, since wellbore instability-related problems could be very challenging and costly, and also affects the operation plan. Therefore, wellbore stability analysis is an important part in design and planning stage in many operating companies. There are several factors that can impact the stability of the well and must be taken into account, such as rock and fracture intrinsic properties, pore pressure, drilling fluid weight, in situ state of stress, and also wellbore trajectory and orientation. Apart from the failure that can happen for intact rock, failure also can occur in rocks intersecting discontinuities.