f Pore Pressure Prediction as a Prospecting Tool, Input to Risk, Volumes and Field Development

Traditionally, pore pressure predictions calculated from offset wells and interval velocity data have been used almost exclusively to design well casings and drilling mud weight programs. However, a pore pressure prediction also contains valuable information on how oil, gas and water is behaving in the subsurface and importantly how fluid pressures will effect top seals, fault seals and column heights in hydrocarbon prospects. PETRONAS Carigali have begun to use pore pressure as a critical input to pre-drill prospect<br>evaluation by combining fault and horizon information, derived from geological maps, with an understanding of how fluid migration and pore pressures, derived from pore pressure predictions, can affect trap risk and volumes. The use of pore pressure predictions as an primary exploration tool has the advantage that it does not require any additional computational work since a pore pressure prediction must be produced in order to design a well. The key change is a modification to the existing exploration workflow so that pore pressures are calculated during the initial exploration stage which allows them to be combined with mapped horizon and fault data to produce integrated geo-pressure / geometric trap scenarios.