Technical Paper

The Analysis of Meaningful Uncertainty in Pore Pressure Prediction

Written by: S. O’Connor and R.H. Oughton

Pre-drill pore pressure models are typically obtained using offset well data and seismic velocities. The workflows used to generate these pressure models are, actually, relatively straightforward and the algorithms used, not complex. However, this is deceptive as there are very many other factors, not just simple-to-understand or visualise issues such as data quality etc, that can mean that the results produced are inaccurate, and at worst, potentially dangerous. One of keys questions therefore is how to reduce the overall uncertainty such that the final pore pressure range is as small as possible. Perhaps the ultimate achievement would be to say what the odds were of the highest modelled pressures “coming in”, rather than saying it’s “possible”.