Real Time Drilling Geomechanics (RTDG) provides relevant real time information and integrated workflow to help clients in reducing operational risk and nonproductive time (NPT) through drilling in marginal economical and technically challenging environments. Dulang-B field is a technical challenge due to its complex structural geological environment. All the existing wells failed to penetrate into deep reservoir F40 sands due to wellbore instabilities issues. Overpressure in F-sands remains always the main concern and challenge which led to unsafe drilling environment and significant nonproductive time in the field. Avoiding drilling surprises means more than being prepared for problems when they occur; it means averting them in the first place. Appropriate safe mud weight to drill each formation, must be defined to overcome different overpressure zones and identify the best position for casing seat of each hole section of the well. With the knowledge acquired through pore pressure and fracture gradient modeling, well behavior could be foretold with enough advance notice to allow drilling team to calmly make technically sound operational decisions that lead to optimal drilling performance.
This study presents the challenges and the main results of the collaborative drilling approach via RTDG (Real Time Drilling Geomechanics) operation in well DL-B28 ST2. This study focuses on the overpressure and narrow safe mud weight window as well as level of uncertainty over prognosis formation tops which has to be managed by integrating LWD seismicVISION* and RTDG which had clear impacts on decision making process. The real time measurement approach by utilizing actual well data provided the best solution to accurately constrain pre-drill pore pressure and fracture gradient model.