Publications

Pore pressure prediction is ordinarily an exclusive job carried out to design a safe and economic drilling mudweight and well design program. Beyond this purpose, a huge benefit is also inherited in the pore pressure prediction. An understanding of pore pressure distribution in the subsurface, integrated with a robust geological model (i.e. regional geology, sequence stratigraphy, structural maps and reservoir connectivity analysis), can lead and direct efforts in the search for hydrocarbons, starting from an early phase of exploration to mature field development. In addition to evaluating trap integrity and risks, pore pressure prediction also has the important capability of revealing the dynamics of oil, gas and water interactions/behaviors in the subsurface.Integration of geological modeling and pore pressure prediction in Nilam field has succeeded in disclosing regional interaction of gas and water in deep overpressure intervals. This integration has identified a tilted top of overpressure, discordantly crossing regional stratigraphic markers in Nilam anticline structure. The discordant top of overpressure triggers differential pressures within water legs of reservoirs in opposite flanks of the anticline. The differential pressure in the opposite water legs push GWC to locate at a higher structural position in the east flank than in the west flank. This analysis reveals a shifted center of gas accumulation to the west flank areas. The new model significantly renews the old model of flat GWC with a center of gas accumulation on the crestal area. The finding suggests a strategy to develop deep overpressure reservoirs in the west flank area of Nilam field.Keywords: Pore pressure prediction, geological model, overpressure, GWC