<div>This report presents the results from detailed palynological analyses of both newly processed samples and re-analysis of existing slides across the upper Permian to Lower Triassic section from the following wells across the southern Bonaparte Basin: Tern 3, Tern 5, Ascalon 1A, Blacktip P1, Blacktip 2, Petrel 1A, Petrel 4, Petrel 5, Prometheus 1, Rubicon 1, Torrens 1. This palynological zonal work is supplemented with palynofacies analyses in a subset of wells. In addition to these new analyses, a review of the existing palynological data from open file palynological reports (in company well completion reports) was undertaken for both the immediately under- and overlying late Permian and earliest Triassic intervals in the newly sampled wells and offset wells of the Tern and Petrel gas fields,&nbsp;including the following wells: Petrel 2, Petrel 3, Petrel 6, Tern 1, Tern 2, Tern 4.</div>

In 2017, 21 new offshore petroleum exploration areas have been released. The majority of the areas are located along the North West Shelf spanning the Westralian Superbasin from the Bonaparte Basin in the north-east to the Northern Carnarvon Basin in the south-west. New areas have been released in offshore south-eastern Australia with new opportunities provided in the Otway, Bass and Gippsland basins. Two large areas in the northern Perth Basin, an offshore frontier, complete the 2017 Acreage Release. All Release Areas are supported by industry nominations and one new cash bid area has been offered in the Dampier Sub-basin. Geoscience Australia continues to support industry activities by acquiring, interpreting and integrating pre-competitive datasets that are made freely available as part of the agency’s regional petroleum geological studies. A new regional 2D seismic survey was acquired in the Houtman Sub-basin of the Perth Basin, forming the basis of the latest prospectivity study carried out by Geoscience Australia. The results of the study are presented in the technical program of the 2017 APPEA conference. A wealth of seismic and well data, submitted under the Offshore Petroleum and Greenhouse Gas Storage Act 2006 (OPGSSA) are made available through the National Offshore Petroleum Information Management System (NOPIMS). Additional datasets are accessible through Geoscience Australia’s data repository. Presented at the 2017 Australian Petroleum Production & Exploration Association (APPEA) Conference.

The upper Permian to Lower Triassic sedimentary succession in the southern Bonaparte Basin represents an extensive marginal marine depositional system that hosts several gas accumulations, including the Blacktip gas field that has been in production since 2009. Development of additional identified gas resources has been hampered by reservoir heterogeneity, as highlighted by preliminary results from a post drill analyses of wells in the study area that identify reservoir effectiveness as a key exploration risk. The sedimentary succession that extends across the Permian–Triassic stratigraphic boundary was deposited during a prolonged marine transgression and shows a transition in lithofacies from the carbonate dominated Dombey Formation to the siliciclastic dominated Tern and Penguin formations. Recent improvements in chronostratigraphic calibration of Australian biostratigraphic schemes, spanning the late Permian and Early Triassic, inform our review of available palynological data and re-interpretation and infill sampling of well data. The results provide a better resolved, consistent and up-to-date stratigraphic scheme, allowing an improved understanding of the timing, duration, and distribution of depositional environments of the upper Permian to Lower Triassic sediments across the Petrel Sub-basin and Londonderry High. <b>Citation:</b> Owens R., Kelman A., Khider K., Iwanec J., Bernecker T. (2022) Addressing exploration uncertainties in the southern Bonaparte Basin: enhanced stratigraphic control and post drill analysis for upper Permian plays. <i>The APPEA Journal</i> 62, S474-S479