A key challenge in exploring Australian onshore sedimentary basins is limited seismic data coverage. Consequently, well logs are often the main datasets that can be used to understand the subsurface geology. The primary aim of this study was to develop a methodology for visualising the three-dimensional (3D) tectonostratigraphic architecture of sedimentary basins using well data, which can then be used to quickly screen areas warranting more detailed studies of resource potential. This project has developed a workflow that generates 3D well correlations using sequence stratigraphic well tops to visualise the regional structural and stratigraphic architecture of the Amadeus, Canning, Officer and Georgina basins in the Centralian Superbasin. Thirteen Neoproterozoic‒Paleozoic supersequence tops were interpreted in 134 wells. Three-dimensional well correlations provide an effective regional visualisation of the tectonostratigraphic architecture across the main depocentres. This study redefines the Centralian Superbasin as encompassing all western, northern and central Australian basins that had episodically interconnected depositional systems driven by regional subsidence during one or more regional tectonic events between the Neoproterozoic and middle Carboniferous. The Centralian Superbasin began to form during Neoproterozoic extension, and underwent several phases of partial or complete disconnection and subsequent reconnection of depositional systems during various regional tectonic events before final separation of depocentres at the culmination of the Alice Springs Orogeny. Regional 3D correlation diagrams have been generated to show the spatial distribution of these supersequences, which can be used to visualise the distribution of stratigraphic elements associated with petroleum, mineral and groundwater systems. <b>Citation: </b>Bradshaw, B., Khider, K., MacFarlane, S., Rollet, N., Carr, L. and Henson, P., 2020. Tectonostratigraphic evolution of the Centralian Superbasin (Australia) revealed by three-dimensional well correlations. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

Geoscience Australia currently uses two commercial petroleum system modelling software packages, PetroMod https://www.software.slb.com/products/petromod and Zetaware http://www.zetaware.com, to undertake burial and thermal history modelling on wells in Australian sedimentary basins. From the integration of geological (age-based sedimentary packages, uplift and erosional events), petrophysical (porosity, permeability, and thermal conductivity) and thermal (downhole temperature, heat flow, vitrinite reflectance, and Tmax) input data, to name the most significant, a best-fit model of the time-temperature history is generated. Since the transformation of sedimentary organic matter (kerogen) into petroleum (oil and gas) is a chemical reaction, it is governed by chemical kinetics i.e. time and temperature (in the geological setting pressure is of secondary importance). Thus, the use of chemical kinetics associated with a formation-specific, immature potential source rock (where available) from the basin of interest is considered a better practical approach rather than relying on software kinetic defaults, which are generally based on the chemical kinetics determined experimentally on Northern Hemisphere organic matter types. As part of the Australian source rock and fluids atlas project being undertaken by the Energy Systems Group’s Exploring for the Future (EFTF) program, compositional kinetics (1-, 2-, 4- and 14-component (phase) kinetics) were undertaken by GeoS4, Germany. The phase kinetics approach is outlined in Appendix 1. This report provides the compositional kinetics for potential source rocks from the Ordovician Goldwyer (Dapingian–Darriwilian) Formation and the Bongabinni (Sandbian) Formation, Carribuddy Group, Canning Basin, Western Australia.

Laboratory results for fluid inclusion gas analysis in GA's Isotope and Organic Geochemistry Laboratory under GSWA Approval G004119

The Canning Basin is a large intracratonic basin in Western Australia that remains one of the least explored Paleozoic basins in the world. Recent resource assessments have renewed interest in the basin, in particular for unconventional gas within Ordovician organic-rich shales, although these proposed plays remain untested. Exploring for the Future (EFTF) is a program dedicated to exploring Australia’s resource potential and boosting investment. Launched in 2016 with $100.5 million in funding from the Australian Government, it initially focused on northern Australia. Geoscience Australia and the Geological Survey of Western Australia collected new, pre-competitive datasets in the frontier Kidson Sub-basin to better understand its energy resource potential. Here we present an overview of the regional petroleum systems with a focus on the modelled Ordovician section within the Kidson Sub-basin and Barnicarndy Graben (previously Waukarlycarly Embayment). Three Larapintine petroleum systems are recognised in the Ordovician (L2), Devonian‒earliest Carboniferous (L3), and Carboniferous (L4) successions of the Canning Basin. Integration of petroleum systems with interpretation of the Kidson Sub-basin seismic survey 18GA-KB1 shows that the Ordovician section is extensive, and hence, the Larapintine 2 Petroleum System is of most exploration interest across this frontier region. Ordovician organic-rich units are known within the Nambeet (Tremadocian–Floian), Goldwyer (Dapingian–Darriwilian) and Bongabinni (Sandbian) formations; however, only Nambeet and Goldwyer source rocks are considered to be present within the Kidson Sub-basin. Oil and gas shows occur within Ordovician and Silurian reservoirs, of which many are sub-salt. The range in the geochemical profile of shows from Goldwyer, Nita and Sahara reservoirs implies generation from numerous source units within the Goldwyer and Bongabinni formations. The origin of oil and gas shows within the Nambeet and Willara formations, including those in Patience 2 in the Kidson Sub-basin, is unknown but imply the presence of multiple lower Ordovician source units and include the Nambeet Formation. Within the Kidson Sub-basin, Kidson 1 is located closest to the main depocentre, whereas other wells are proximal to shelves and margins. In general, these latter wells return discouraging hydrocarbon potential pyrolysis parameters as a consequence of their sub-optimal location for source rock development and thermal maturation history. Kidson 1 penetrates the Goldwyer Formation and has TOC contents that are considered more representative of source rock richness (although diesel contamination is present) within the depocentre. Data paucity is the key limitation in resource evaluation for the Kidson Sub-basin, as such, an evaluation with volumetrics is not possible. 1D petroleum systems models of ten wells located in either the Kidson Sub-basin, Willara Sub-basin or Barnicarndy Graben were constructed to resolve whether potential source rocks were capable of hydrocarbon generation. The models demonstrate maturation of Ordovician source rocks resulting in near-complete transformation during Permian to Triassic deposition and burial. A 2D petroleum systems model constructed along the regional 2D seismic line 18GA-KB1 predicts full maturation of Larapintine 2 source rocks in the deeper parts of the Kidson Sub-basin. Expulsion and migration is considered to have taken place during the Permian‒Triassic, with potential accumulations trapped by evaporitic and fine-grained units of Ordovician and Silurian age.

A large proportion of Australia’s onshore sedimentary basins remain exploration frontiers. Industry interest in these basins has recently increased due to the global and domestic energy demand, and the growth in unconventional hydrocarbon exploration. In 2016, Geoscience Australia released an assessment of eight central Australian basins that summarised the current status of geoscientific knowledge and petroleum exploration, and the key questions, for each basin. This publication provides a comprehensive assessment of the geology, petroleum systems, exploration status and data coverage for additional three basins in western and central Australia: the Canning, Perth and Officer basins. The Perth and Canning basins are producing petroleum basins, however, they may be regarded as frontier basins for unconventional hydrocarbon resources. The Officer Basin is a large, unproven frontier basin which has seen little exploration to date.

The Kidson Sub-basin covers ~91 000 km2, and is a largely under-explored and sparsely imaged region of the Canning Basin in northern Western Australia. The 872 km Kidson Sub-basin seismic survey was acquired to enhance understanding of the subsurface and thereby assist in the assessment of the region for hydrocarbon and mineral potential. Specifically, the survey aimed to improve basin-wide stratigraphic correlation, determine the extent of basin depocentres, image major structures and place constraints on the sub-basin’s geological event history. The new seismic profile reveals that the Kidson Sub-basin is ~500 km long and ~6.5 km deep. It contains a lower conformable package of Ordovician to Devonian clastic sediments, carbonates and evaporites unconformably overlain by the clastic-dominated Permian Grant Group and Poole Sandstone. Normal faults imaged at the base of the sequence with growth strata in the hanging wall constrain rifting to between Cambrian and Silurian in age. Folding along the southeastern edge of the basin is inferred to be a consequence of the Carboniferous Meda Transpression linked to the Alice Springs Orogeny in central Australia. The known source rocks of the Goldwyer and Bongabinni formations have been interpreted to extend across the Kidson Sub-basin, which is encouraging for energy prospectivity in the region. <b>Citation:</b> Southby, C., Carr, L.K., Henson, P., Haines, P.W., Zhan, A., Anderson, J.R., MacFarlane, S., Fomin, T. and Costelloe, R., 2020. Exploring for the Future: Kidson Sub-basin seismic interpretation. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

This report presents the results of scanning electron microscopy (SEM) and mercury porosimetry analyses on 1 whole core sample from the GSWA Waukarlycarly 1 stratigraphic well drilled in the Canning Basin. The well was drilled as part of a co-funded collaboration between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) aimed at gathering new subsurface data on the potential mineral, energy and groundwater resources in the southern Canning Basin. The collaboration resulted in the acquisition of the Kidson Deep Crustal Seismic Reflection Survey in 2018; and the drilling of deep stratigraphic well GSWA Waukarlycarly 1, located along the Kidson Sub-basin seismic line within the Waukarlycarly Embayment in 2019 (Figure 1). GSWA Waukarlycarly 1 reached a total depth of 2680.53 m at the end of November 2019 and was continuously cored through the entire Canning Basin stratigraphy. Coring was complemented by the acquisition of a standard suite of wireline logs and a vertical seismic profile. The work presented in this report constitutes part of the post well data acquisition. The purpose of the SEM analysis was to determine mineralogy and textural relationships between grains, verify the presence of organic material at the micro-scale, document i) the presence of diagenetic alterations to the detrital mineral assemblage and ii) eventual distribution of visible pores. Additionally, mercury injection capillary pressure porosimetry (MICP) was used to assess interconnected porosityand pore size distribution.

This report presents the results of an elemental and carbon and oxygen isotope chemostratigraphy study on three historic wells; Kidson-1, Willara-1 and Samphire Marsh-1, from the southern Canning Basin, Western Australia. The objective of this study was to correlate the Early to Middle Ordovician sections of the three wells to each other and to wells with existing elemental and carbonate carbon isotope chemostratigraphy data from the Broome Platform, Kidson and Willara sub-basins, and the recently drilled and fully cored stratigraphic Waukarlycarly 1 well from the Waukarlycarly Embayment.

The onshore Canning Basin in Western Australia is the focus of a regional hydrocarbon prospectivity assessment being undertaken by the Exploring for the Future (EFTF) program; an Australian Government initiative dedicated to increasing investment in resource exploration in northern Australia. The four-year program led by Geoscience Australia focusses on the acquisition of new data and information about the potential mineral, energy and groundwater resources concealed beneath the surface in northern Australia and parts of South Australia. As part of this program, significant work has been carried out to deliver new pre-competitive data including new seismic acquisition, drilling of a stratigraphic well, and the geochemical analysis of geological samples recovered from exploration wells. A regional, 872 km long 2D seismic line (18GA-KB1) acquired in 2018 by Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA), images the Kidson Sub-basin of the Canning Basin. In order to provide a test of geological interpretations made from the Kidson seismic survey, a deep stratigraphic well, Waukarlycarly 1, was drilled in 2019 in partnership between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) in the South West Canning Basin. The Waukarlycarly 1 stratigraphic well was drilled in the Waukarlycarly Embayment, 67 km west of Telfer and provides stratigraphic control for the geology imaged by the Kidson seismic line (Figure 1). The well was drilled to a total drillers depth (TD) of 2680.53 mRT and penetrated a thin Cenozoic cover overlying a Permian fluvial clastic succession that includes glacial diamictite. These siliciclastics unconformably overlie an extremely thick (>1730 m) interpreted Ordovician succession before terminating in low-grade metasediments of Neoproterozoic age. Log characterisation, core analysis, geochronology, petrographic and palaeontological studies have been carried out to characterise the lithology, age and depositional environment of these sediments. As part of this comprehensive analytical program, magnetic susceptibility and bulk density analyses were undertaken by Geoscience Australia on selected rock samples.

<p>The Paleozoic Canning Basin is a large (~720 000 km2) frontier province with several proven petroleum systems. Recent oil production from the Ungani field on the southern edge of the Fitzroy Trough has boosted the small-scale production of crude oil and gas discovered in the 1980s on the Lennard Shelf and flanking terraces (e.g. Blina, Boundary, Lloyd, Sundown, West Kora, West Terrace). Determining the paleo-depositional environments within the epicontinental seaway is essential to characterise source rock formation and distribution, and hence assist future exploration strategies.</p> <p>This study of diagnostic biomarker hydrocarbons derived from the coloured carotenoid pigments of photosynthetic organisms (including plants, algae, cyanobacteria and photosynthetic bacteria) was designed to extend the geochemistry of the Ordovician-, Middle to Late Devonian- and Early Carboniferous-sourced oils of the basin published by Edwards et al. (2013) and Spaak et al. (2017, 2018), and implemented by GeoMark Research. The focus was to clarify the paleo-depositional environment of their marine source rocks and the extent of water stratification, and to expand upon the diversity of the contributing organic matter. The oils on the Lennard Shelf and those on the southern side of the Fitzroy Trough (e.g. Ungani and Dodonea 1) preserve a diverse range of biomarkers, including both saturated and aromatic C40 carotenoid-derived compounds (Figure 1) due to minimal secondary alteration. All analysed oils contain the saturated biomarker beta-carotane, derived from algae and cyanobacteria that flourish in sunlit oxygenated water. In addition, the oils also contain aromatic carotenoids produced by photosynthetic green sulphur bacteria, which inhabit the photic zone of euxinic water columns (e.g. Summons & Powell, 1986; French et al., 2015). Paleorenieratane is the dominant C40 aromatic carotenoid in the Ordovician (Dodonea 1, Pictor) and Late Devonian-sourced oils (Blina 1, 2, 4 and Janpam North 1; Figure 1). Oils on the Lennard Shelf generated by Lower Carboniferous source rocks have variable distributions of carotenoids with isorenieratane either in similar concentration to paleorenieratane (Point Torment 1, Sundown 2), absent (West Kora 1) or, in the case of Terrace 1, in lower abundance relative to paleorenieratane. Paleorenieratane, isorenieratane and renieratane are absent in oils from Wattle 1 ST1 and Mirbelia 1. Chlorobactane, also derived from green sulphur bacteria, is present in many of the analysed oils (and is the dominant peak in Point Torment 1), whereas okenane (derived from purple sulphur bacteria) was not detected. The exception is the Late Ordovician (Sandbian) Cudalgarra 1 oil that contains a low concentration of okenane, and in which isorenieratane predominates over paleorenieratane. The aromatic carotenoid distribution in oil from Ungani 2 is similar to those from both Terrace 1 and Blina (Figure 1).</p> <p>The association of these saturated and aromatic carotenoids in Paleozoic Canning Basin oils provides evidence for long-term restricted circulation and the development of shallow chemoclines in an epicontinental seaway centred along the Fitzroy Trough and Gregory Sub-basin in which oxygenated surface water frequently overlaid deeper, anoxic, sulphidic (euxinic) water also within the photic zone.</p> <p>REFERENCES Edwards, D.S., Boreham, C.J., Chen, J., Grosjean, E., Mory, A.J., Sohn, J., Zumberge, J.E., 2013. Stable carbon and hydrogen isotopic compositions of Paleozoic marine crude oils from the Canning Basin: comparison with other west Australian crude oils. In: Keep, M., Moss, S. (Editors), The Sedimentary Basins of Western Australia IV, Perth, WA. Edwards, P., Streitberg, E., 2013. Have we deciphered the Canning? Discovery of the Ungani oil field. In: Keep, M., Moss, S. (Editors), The Sedimentary Basins of Western Australia IV, Perth, WA. French, K.L., Rocher, D., Zumberge, J.E., Summons, R.E., 2015. Assessing the distribution of sedimentary C40 carotenoids through time. Geobiology 13, 139–151, 10.1111/gbi.12126. Spaak, G., Edwards, D.S., Allen, H.J., Grotheer, H., Summons, R.E., Coolen, M.J.L., Grice, K., 2018. Extent and persistence of photic zone euxinia in Middle–Late Devonian seas – insights from the Canning Basin and implications for petroleum source rock formation. Marine and Petroleum Geology, 93, 33–56. Spaak, G., Edwards, D.S., Foster, C.B., Pagès, A., Summons, R.E., Sherwood, N., Grice, K., 2017. Environmental conditions and microbial community structure during the Great Ordovician Biodiversification Event; a multi-disciplinary study from the Canning Basin, Western Australia. Global and Planetary Change, 159, 93–112. Summons, R.E., Powell, T.G., 1986. Chlorobiaceae in Palaeozoic seas revealed by biological markers, isotopes and geology. Nature 319, 763–765.</p>