Feasibility study of underbalanced drilling using geomechanical parameters and finite element method

Abstract Wellbore instability causes main concerns in the oil and gas industry due to personnel safety overall expenditure. Several signs such as wellbore spalling, rate of penetration reduction, pipes sticking, well unnatural wash out, collapsing, induce fracture could indicate during drilling. A balance between stress concentration near rock strength is primary condition for a stability Thus, failure rocks occurs when intensity effective exceeds strength. In underbalanced drilling (UBD), considered unstable since no pressure or maybe not enough applied on from fluid, pore undesirable wellbore, so difference these two pressures wellbore. Consequently, issue UBD approach great importance. mainly used reduce damage geological formation risk fluid loss while increasing rate. This study has investigated Iranian Oilfield using FLAC software considering yielded regions (plastic) different mud weights. The investigation analysis output plots, especially plasticity plot, concluded that ideal optimal applying conditions also ensuring ranges 15.2–16.8 MPa.