Tectonostratigraphic controls on pore fluid pressure distribution across the Taranaki Basin, New Zealand

Abstract

Pore fluid pressure distribution within a sedimentary basin is controlled by a combination of factors, including stratigraphic stacking, lithofacies distribution, fault zone permeability, sedimentation rate, diagenesis, petroleum generation and structural evolution. Basins with an initial rift phase coupled with high sedimentation rates often display pore fluid pressures above hydrostatic, but subsequent structural shortening can drastically alter the initial distribution of pore fluid pressure. Pore fluid pressure in excess of the hydrostatic gradient (overpressure) has been shown in several sedimentary basins to increase basinward (e.g. Javanshir et al., 2015;Tingay et al., 2005;Van Balen & Cloetingh, 1994;Zoccarato et al., 2018) due to a gradual reduction in sand-to-mudrock ratio (net-to-gross),