3D Pore Pressure Prediction Model in Bentu Block-Central Sumatra Basin

Behaki, Wawan A.; Sukapradja, Aldyth; Siregar, Ronald C.; Djaelani, Setiabudi; Sjafwan, Benny
Exploration, Energi Mega Persada, Jakarta, Indonesia.

Pore Pressure Prediction is crucial work in preparing for a proper drilling program especially if there is any shallow overpressure gas formation . It emphasizes among others for the purposes of casing design, determination of drilling mud weight and mitigation of overpressure as a drilling hazard. In Bentu & Korinci Block, it occurred some blow-out wells i.e. Baru-1 (1951), Baru-2(1967), Korinci-1 (1983) as well as Segat-1 well (1965), because of overpressure in Binio Formation. These events lead us to conduct pore pressure study for safety reason.

The study itself is based on available data : wireline log data , pressure test, 2D Seismic and drilling data.. The Eaton Methods recently is the best method to calculate pore pressure from sonic, resistivity and density log. Result from resistivity data is not quite proper to characterize the pressure data in this area, and the other factor is incomplete density data, with the result that the sonic log is the most appropriate source data. The fundamental aspect in 3D pore pressure distribution is an empirical relationship between the pore pressure and velocity. This relationship enable the pore pressure prediction to be distributed in 3D model that follow the trend of the velocity.

After having the pore pressure 3D modeling in the Bentu Block, it allows us to predict the pore pressure in 3D view. This study result is very important to design a drilling program especially in well delineation, in the other hand this model can help drilling department to prepare casing design, drilling mud weight program and overpressure prediction to prevent the drilling hazard.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012