Potential for Mukuyu-1's Results to be Above Market Expectations, page-250

"....In absence of direct data is it possible to guestimate reservoir pressure from the below info:
Gas shows up to 35 times above background in Upper Angwa despite 2500psi overbalance.. "

Mud gas levels are influenced by numerous factors. Mud gas levels/trends can give you an indication of whether a well is overbalanced or underbalanced but it's impossible to work a mud gas reading into a formation pressure.

Actual formation pressure can only be arrived at by taking measurements with a downhole pressure gauge (wireline/LWD formation tester or DST gauges) or sometimes a well kill operation can yield information about down hole pressures.