Pore Pressure Prediction in Frontier Exploration - The Before, the During and the After. How Well Did We Do?

In a frontier exploration basin, determining the pore pressure for an upcoming well is very challenging where the primary objective is for the exploration well to be drilled in a safe and cost efficient manner. Where minimal offset data exists, seismic interval velocities along with an interpretation of the geological depositional system is often the primary data used to construct the pore pressure model for the basin. From this a pore pressure ‘base case’ is determined for the prospect location which is then used in the pre-drill well design process. During the operational phase of the 1st well, the pre-drill ‘base case’ becomes a secondary guide and it is the wellbore and drilling parameters that is the primary data source for dictating the ‘base case’ while drilling. The focus shifts again in the post wells analysis and planning phase of the next well where the primary data for the ‘base case’ pore pressure profile for the 2nd well is now the hard offset geological and geophysical data gained form the first well. The secondary data sources (seismic interval velocities & geological interpretation) then help to form the pore pressure envelope around the base case.