Potential for Mukuyu-1's Results to be Above Market Expectations, page-247

The 2500 psi overbalance would probably have been estimated by IVZ with reference to a measured RCX pretest pressure? However, the RCX pressures have not been made public.

There are methods for estimating pore pressure (reservoir fluid pressure), but some are empirical (fit to regional data). I have always relied on the modular dynamic formation tester tool (MDT) or equivalent to determine accurate pore pressure prior to casing off a well.

Other methods for estimating pore pressure include. (I do not have hands on experience of these methods):

Eaton method,
Ratio method,
Equivalent depth method,
Resistivity method with depth-dependent normal compaction trendline (NCT),
Sonic method with depth-dependent normal compaction trendline (NCT),
and the effective stress method.