Uncertainty evaluation of wellbore stability for determining proper mud weight using by Monte Carlo

Uncertainty evaluation of wellbore stability for determining proper mud weight using by Monte Carlo

With use of Monte Carlo simulation and information that received from petrophysics and geomechanics and using uniform distribution for input variables and a specific failure criteria, two charts drew. One of them is collapse or fracture pressure distribution and the other probability of collapse or fracture for various mud weight, in other words cumulative of pressure distribution. Our golf is estimate the proper mud weight that reduce problems. Interpret the charts and get the proper mud weight. Wellbore stability analyzed with various mud weight too. Two types of failure criteria used. The first is criterion that used by “John Emeka Udegbunam, Bernt Sigve Aadnøy” for vertical well. With use of this criterion mud weight is 1.69 specific gravity (sg).The second is Mohr-Coulomb shear-failure criterion. By using this criterion the calculated mud weight is between 1.30 sg and 2.28 sg