Oil-Source Rock Correlations in the Maui-4 Oil Exploration Well, South Taranaki Basin

Abstract
This paper presents the results of an organic geochemical biomarker study of the oil and the coals at different depths in the Maui-4 oil exploration well. The n-alkane distribution suggests that the oil is progressively generated in the coals with increasing depth from about 6800', but significant generation does not lake place until about 10600'. Although at 12770' the lighter oil fraction is released, the majority of the oil is largely retained in the coal matrix. It is only in the deepest 12780' coal that the maturity parameters derived from the sterane and hopane biomarkers approach those in the produced oil. It is therefore likely that the probable source rock for the Maui-4 oil is even deeper. Extrapolation of these biomarker parameters suggests the oil is sourced by the Pakawau coals or possibly the associated shales between 13000–13500'.