Crampton, J.S.; Morgans, H.E.G. 2007 Application of high-resolution quantitative biostratigraphic correlation to exploration licence blocks PEP 38488-38489. Lower Hutt, N.Z.: GNS Science. GNS Science report 2006/01 12 p.
Abstract: This report describes a high-resolution biostratigraphic study of four hydrocarbons exploration wells in the Taranaki Basin that are relevant to licence blocks PEP 38488-38489: Arawa-1, Okoki-1, Taimana-1 and Witiora-1. The analysis was supplemented by an existing biostratigraphic dataset from six additional wells: Ariki-1, Kiwa-1, Tane-1, Tangaroa-1, Turi 1, Wainui-1. The analysis employs automated multidimensional graphic correlation by constrained optimization, as implemented in the computer program CONOP. It is based on 1,726 biostratigraphic events that are distributed across 1,107 sample horizons with average sample spacing in all the wells of 20 m. In addition, we have included 19 synthetic seismic ties in three wells. The resulting age-calibrated CONOP composite section has 637 levels, ranging in age from 61 Ma to 2.5 Ma, which can be used to correlate the wells. The age model used to calibrate the composite was based on 70 independently dated events. The composite section yields an average time resolution of 92 kyr through the study interval, which represents a greater than ten-fold improvement in potential biostratigraphic resolution over previous stage and zonal schemes. In reality, dating resolution in any well is limited by sample spacing in that well. The composite is used to identify unconformities that are common to all the sampled wells and to generate refined age-depth plots. In addition, it allows us to date or locate the synthetic seismic ties according to two different assumptions: a) seismic ties are isochronous but unreliably located, and b) seismic ties are non-isochronous but reliably located. (auth)