
%0 Journal Article
%A Humphris, D. 
%A Ravens, J. 
%T A braver approach to seismic velocity analysis in the Taranaki Basin, New Zealand
%J Exploration Geophysics
%D 2000/06/01
%V 31
%N 2
%P 267-269
%K 
%R https://doi.org/10.1071/EG00267
%U https://www.publish.csiro.au/paper/EG00267 
%X The Institute of Geological and Nuclear Sciences (GNS) recently re-processed a set of 1991 2-D seismic reflection data from the offshore Taranaki region for the Spectrum Exploration/Fletcher Challenge Energy Taranaki Joint Venture. A more detailed stacking velocity analysis, incorporating a 40% interval velocity inversion in the Eocene units, resulted in a markedly improved seismic image of Eocene and deeper reflectors. A dense semblance analysis formed the initial part of the velocity analysis sequence. It was followed by interactive constant velocity stack analysis of the velocity inversion, where the weak intra-Eocene reflectors were masked in amplitude by multiples from an overlying strong limestone reflection. A third, automatic, velocity analysis was performed on the final stack using a combination of semblance and digitised horizon times, producing a horizon-based velocity model with data points every 5 traces (63 metres). The combination of these analyses can provide relatively accurate estimates of interval velocities needed in the calculation of overpressures in basin modelling studies. 
