Analysis Of Pore Pressure Using Geophysical Methods

Abstract

Many methods have been devised for predicting and evaluating the values of pore pressure in oil and gas formations. The present work employs geophysical approach for prediction of formation pore pressure in Niger Delta. This involved the use of seismic derived data before drilling operation, which was correlated with sonic, and density logs data gathered after drilling. The analysis shows that at a depth of about 11177ft when interval transit time starts to increase, high pore pressure is likely to be encountered. At SP 257, which is about 3miles from a proposed drilling location, it is predicted that high pore pressure will occur at about 7600ft. Also at SP 1035, onset of abnormal pressure was predicted to be at 7300ft depth. Correlation with M W D resistivity data at SP 182 reveals that the prediction closely match the real values at shot point 1035 which is 500ft from the proposed well location.

KEY WORDS: Pore Pressure, Geophysical, Prediction

Global Journal of Engineering Research Vol.3(1&2) 2004: 39-45