Analysis of subsurface pressure data from Taranaki Basin, utilising direct (e.g. Repeat Formation Tester, RFT) and indirect measurements (drilling parameters and wireline log data such as sonic and resistivity), indicates the presence of three pressure cells: a near-hydrostatic compartment (Cell A) that extends across the entire basin, an underlying overpressured compartment (Cell B), with pressures around 1100 psi (7.584 MPa) above hydrostatic, that extends throughout the Manaia Graben and north along the eastern basin margin at depths of 1900 – 4100 m, and a third compartment (Cell C), with approximately 2100 psi (14.479 MPa) overpressure, that directly underlies Cell A and Cell B in different parts of the basin (although well penetrations are limited).