Takapou-1: Geochemical Analysis

This report compiles the analysis of three samples from Takapou-1 (from within PEP38482 offshore North Taranaki) which were analysed to assess whether oil shows reported on the mud log could be typed to the expected Cretaceous oil source. Confirmation of a Cretaceous oil would have confirmed presence of migrated oil as the sequence sampled is of Paleocene age. Unfortunately the extracted hydrocarbon did not match so the oil shows remain equivocal. Vitrinite reflectance data indicates that the sampled interval could be close to early maturity and it is possible that the minor shows reported were a result of early in situ generation.; Although high levels of hydrocarbon were extracted, this did not have the character of the expected oil. The sediments are immature but approaching early maturity and the shows could have been generated in situ, or are the result of mud additives. The black material seen in the unwashed cuttings is not consistent with mud log descriptions, but no unusual additives are reported in the mud engineer’s report. The origin of the shows at this level in Takapou-1 therefore remain equivocal.