Publications

The Pertamina exploration area in North Sumatra has High Pressure and High Temperature (HPHT) fields. The pore pressure is up to 2.2 g/cm3 and the temperature is more than 350�F. Several wells had been drilled since 2003 and the exploration study is continuing in this field. The drilling campaign for the upcoming wells is set and targets the same formation, so it probably will encounter similar geomechanics issues as the existing wells. To achieve the drilling target, a geomechanics model must be developed. A narrow mud weight window is suspected. A 1D geomechanics Mechanical Earth Model (MEM) was constructed based on well-logs data and drilling reports in the existing wells. Drilling reports were reviewed carefully to capture drilling problems to help the MEM computation. The availability of uniaxial core laboratory test was another important data source to validate the MEM computed from the well-logs data. With the validation of the laboratory test, the MEM results will give good guidance to achieve the drilling target in the same formation over the field. Validated geomechanics MEM in this field will create accurate pre-drill wellbore stability analysis for the upcoming exploration wells. Wellbore stability analysis is used in well planning to define the borehole trajectory, casing design and mud-weight recommendation. The accuracy of the geomechanics model is extremely important to minimize the drilling risk and enable accurate planning and mitigation.