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 scanning electron microscopy (SEM) analyses on 2 core samples 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.

Geoscience Australia’s Exploring for the Future (EFTF) program has established new techniques to collect onshore pre-competitive datasets on an unprecedented scale. The Exploration Incentive Scheme (EIS) is a Western Australian Government initiative that aims to encourage exploration for the long-term sustainability of the state’s resources sector. Integration of EFTF and EIS datasets has improved understanding of the geology across northern Australia, and the associated energy, mineral and groundwater resources potential. The onshore Canning Basin covers approximately 530 000 km2, and has proven prospectivity for conventional oil and gas, mainly in the northern part of the basin. Potential exists for unconventional resources that remain largely unexplored and untested. Gas resource assessments suggest that the basin has significant potential for recoverable shale gas and tight gas. Even with exploration continuing along the flanks of the Fitzroy Trough, the Canning Basin remains one of the least explored Paleozoic basins in the world (DMIRS, 2020). Australia’s longest onshore seismic line, 18GA-KB1, acquired in the southern Canning Basin addresses a long standing data gap across the Kidson Sub-basin and Waukarlycarly Embayment that assists with the resource evaluation of this frontier region. The Kidson Sub-basin covers 91 000 km2 and has a sag basin architecture. Preliminary interpretation of the seismic data indicates that the sedimentary basin is approximately 6 km deep, and includes a conformable package of Ordovician–Devonian siliciclastic, carbonate and evaporite facies of exploration interest. The Carboniferous succession is interpreted as not being present. Located on the western end of the seismic line, the newly drilled deep stratigraphic well Waukarlycarly 1 penetrated 2680.53 m of Cenozoic and Paleozoic strata and provides stratigraphic control for the geology imaged in the Waukarlycarly Embayment. A comprehensive elemental and δ13C isotope chemostratigraphy study assists with stratigraphic correlations within Ordovician sedimentary strata across the region (Forbes et al., 2020a, b). Oil and gas discoveries throughout the Canning Basin were generated from Paleozoic marine source rocks, deposited under stratified oxic and euxinic water columns. Three distinct petroleum systems, the Ordovician (Larapintine 2), Late Devonian (Larapintine 3) and latest Devonian–early Carboniferous (Larapintine 4), are recognized based on the geochemical character of their associated fluids and each display strong stratigraphic control (Carr et al., 2020). Widespread generation of gas from Paleozoic sources is evident from molecular analyses of gases recovered from petroleum wells and fluid inclusions (Boreham et al., 2020). Currently the Larapintine 2 Petroleum System is deemed most prospective system in the Kidson Sub-basin.

<p>A geochemical study was conducted to establish oil-oil correlations and evaluate potential source rocks within the latest Devonian–earliest Carboniferous succession of the onshore Canning Basin, Western Australia. Aromatic hydrocarbons, together with the routinely used saturated biomarker ratios and stable carbon isotopes, demonstrate that the recently discovered Ungani oilfield located on the southern margin of the Fitzroy Trough are similar, but not identical, to the early Carboniferous Larapintine 4 (L4) oil family present to the north of the Fitzroy Trough on the Lennard Shelf. The L4 oil family has been correlated to a lower Carboniferous (Tournaisian) source rock core sample from the Laurel Formation at Blackstone-1 although its bulk geochemical properties signify that it could generate substantially more gas than liquid hydrocarbons. <p>The Ungani oils can be distinguished from the L4 oils by their higher concentrations of paleorenieratane and isorenieratane, coupled with more depleted &delta;¹³C values for n-alkanes, pristane and phytane compared with other components. Hopane isomerisation ratios show distinct grouping of the two oil families that reflect both source and maturity variations. The oil from Wattle-1 ST1 on the Lennard Shelf also has an unusual composition, exhibiting some molecular and isotopic features similar to both the L4 and Ungani oils. Source rocks for the Ungani and Wattle-1 ST1 oils are unknown since their geochemical signature does not match that of the Tournaisian Laurel Formation or the Middle−Upper (Givetian–Frasnian) Devonian Gogo Formation which sourced the Devonian-reservoired Larapintine 3 oils at Blina and Janpam North-1. It is postulated that such potential oil-prone source rocks could occur within the Famennian–Tournaisian succession. <b>Citation:</b> Gemma Spaak, Dianne S. Edwards, Clinton B. Foster, Andrew Murray, Neil Sherwood, Kliti Grice, Geochemical characteristics of early Carboniferous petroleum systems in Western Australia,<i> Marine and Petroleum Geology</i>, Volume 113, 2020, 104073, ISSN 0264-8172. https://doi.org/10.1016/j.marpetgeo.2019.104073

Geoscience Australia’s Exploring for the Future Program is investigating the mineral, energy and groundwater resource potential of sedimentary basins and basement provinces in northern Australia and parts of South Australia. A key challenge in exploring Australian onshore sedimentary basins is that these are often areas with limited seismic data coverage to image the sub-surface structural and stratigraphic architecture. Consequently, well logs are often the main data sets that are used to understand the sub-surface geology. Where good seismic data coverage is available, a considerable amount of time is generally required to undertake an integrated interpretation of well and seismic data. The primary aim of this study is to develop a methodology for visualising the three-dimensional tectonostratigraphic architecture of sedimentary basins using just well data, which can then be used to quickly screen areas warranting more detailed studies of resource potential. A workflow is documented which generates three-dimensional well correlations using just well formation tops to visualise the regional structural and stratigraphic architecture of the Amadeus, Canning, Officer and Georgina basins in the Centralian Superbasin. A critical step in the workflow is defining regionally correlatable supersequences that show the spatial linkages and evolution through time of lithostratigraphic units from different basin areas. Thirteen supersequences are defined for the Centralian Superbasin, which were deposited during periods of regional subsidence associated with regional tectonic events. Regional three-dimensional correlation diagrams have been generated to show the spatial distribution of these supersequences, which can be used as a reconnaissance tool for visualising the distribution of key stratigraphic elements associated with petroleum, mineral and groundwater systems. Three-dimensional well correlations are used in this study to redefine the Centralian Superbasin as encompassing all western, northern and central Australian basins that had 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 a series of Neoproterozoic rift-sag events associated with the break-up of the Rodinia Supercontinent at about 830 Ma. Depositional systems in the Amadeus and Officer basins were partially disconnected by an emergent Musgrave Province during these early stages of superbasin evolution. Subsequent regional uplift and erosion of the superbasin occurred during the late Neoproterozoic–early Cambrian Petermann Orogeny. The Officer and Amadeus were permanently disconnected by the uplifted Musgrave Province following this major orogenic event. Rejuvenation of the Centralian Superbasin occurred during middle–late Cambrian extension and subsidence resulting in the generation of several new basins including the Canning Basin. Subsidence during the Ordovician Larapinta Event created an intracontinental seaway that episodically connected the Canning, Amadeus, Georgina and Officer basins to the proto-Pacific Ocean in the east. Fragmentation of the Centralian Superbasin began at the onset of the Alice Springs Orogeny during the Rodingan Event when the uplifted Arunta Region disconnected the Amadeus and Georgina basins. The Rodingan Movement initially disconnected depositional systems between the Canning and Amadeus basins, which promoted the development of a large evaporitic depocentre over the southern Canning Basin. However, these basins subsequently reconnected during the Early Devonian Prices Creek Movement. Complete fragmentation of the Centralian Superbasin occurred during the Late Devonian–middle Carboniferous Pillara Extension Event when the Canning and Amadeus basins became permanently disconnected. Widespread uplift and erosion at the culmination of the Alice Springs Orogeny in the middle Carboniferous resulted in final closure of the Centralian Superbasin.

The Ordovician is an important period in Earth’s history with exceptionally high sea levels that facilitated the Great Ordovician Biodiversification Event. This crucial biological event is regarded as the second most significant evolutionary event in the history of Paleozoic life, after the Cambrian radiation. The present study integrates palynological, petrographic, molecular and stable isotopic (δ13C of biomarkers) analyses of cores from five boreholes that intersected the Goldwyer Formation, Canning Basin, Western Australia, to determine depositional environments and microbial diversity within a Middle Ordovician epicontinental, tropical sea. A major transgression was detected in the laminated shales of the lower Goldwyer Formation (Units 1+2) which were deposited in anoxic bottom waters, as confirmed by low (<1) Pristane/Phytane ratios, and elevated dibenzothiophene and gammacerane indices. A second, less extensive, flooding event is recorded by shallow marine sediments of the upper Goldwyer Formation (Unit 4). Cores of these sediments, from two wells (Solanum-1 and Santalum-1A) are bioturbated and biomarkers indicate relatively oxygenated conditions, as well as the presence of methanotrophic bacteria, as determined from the high 3-methylhopane indices. Typical Ordovician marine organisms including acritarchs, chitinozoans, conodonts and graptolites were present in the lower and upper Goldwyer Formation, whereas the enigmatic organism Gloeocapsomorpha prisca (G. prisca) was only detected in Unit 4. The presence of G. prisca was based on microfossils and specific biosignatures presenting an odd-over-even predominance in the C15 to C19 n-alkane range. Cryptospores were identified in Unit 4 in the Theia-1 well and are most likely derived from bryophytes, making this is the oldest record of land plants in Australian Middle Ordovician strata. Biomarkers in some samples from Unit 4 that also support derivation from terrestrial organic matter include retene, benzonaphthofurans and δ13C-depleted mid-chain n-alkanes. This research contributes to understanding Ordovician marine environments from a molecular perspective since few biomarker studies have been undertaken on age-equivalent sections. Furthermore, the identification of the oldest cryptospores in Australia and their corresponding terrestrial biomarkers contributes to understanding the geographical evolution of early land plants.

Although the Canning Basin has yielded minor gas and oil within conventional and unconventional reservoirs, the relatively limited geological data available in this under-explored basin hinder a thorough assessment of its hydrocarbon potential. Knowledge of the Paleozoic Larapintine Petroleum Supersystem is restricted by the scarcity of samples, especially recovered natural gases, which are limited to those collected from recent exploration successes in Ordovician and Permo-Carboniferous successions along the margins of the Fitzroy Trough and Broome Platform. To address this shortcoming, gases trapped within fluid inclusions were analysed from 121 Ordovician to Permian rock samples (encompassing cores, sidewall cores and cuttings) from 70 exploration wells with elevated mud gas readings. The molecular and carbon isotopic compositions of these gases have been integrated with gas compositions derived from open-file sources and recovered gases analysed by Geoscience Australia. Fluid inclusion C1–C5 hydrocarbon gases record a snapshot of the hydrocarbon generation history. Where fluid inclusion gases and recovered gases show similar carbon isotopes, a simple filling history is likely; where they differ, a multicharge history is evident. Since some fluid inclusion gases fall outside the carbon isotopic range of recovered gases, previously unidentified gas systems may have operated in the Canning Basin. Interestingly, the carbon isotopes of the fluid-inclusion heavy wet gases converge with the carbon isotopes of the light oil liquids, indicating potential for gas–oil correlation. A regional geochemical database incorporating these analyses underpins our re-evaluation of gas systems and gas–gas correlations across the basin. <b>Citation:</b> Boreham, C.J., Edwards, D.S., Sohn, J.H., Palatty, P., Chen, J.H. and Mory, A.J., 2020. Gas systems in the onshore Canning Basin as revealed by gas trapped in fluid inclusions. 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.

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.

Exploring for the Future is a four year $100.5 million initiative by the Australian Government conducted in partnership with state and Northern Territory government agencies and universities that aims to boost northern Australia's attractiveness as a destination for investment in resource exploration. The acquisition of deep crustal seismic reflection data in the Kidson Sub-basin (Canning Basin) between the Kiwirrkurra community and Marble Bar in northern Western Australia was a major EFTF deliverable, and was completed in August 2018. This paper presents the preliminary geological interpretation of the sedimentary succession imaged by the Kidson Sub basin seismic line.

A regional hydrocarbon prospectivity study was undertaken in the onshore Canning Basin in Western Australia as part of the Exploring for the Future (EFTF) program, an Australian Government initiative dedicated to driving investment in resource exploration. 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, Barnicarndy 1, was drilled in 2019 in a partnership between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) in the Barnicarndy Graben, 67 km west of Telfer, in the southwest Canning Basin. Drilling recovered about 2100 m of continuous core from 580 mRT to the driller’s total depth (TD) of 2680.53 mRT. An extensive analytical program was carried out to characterise the lithology, age and depositional environment of these sediments. This data release presents organic geochemical analyses undertaken on rock extracts obtained from cores selected from the Barnicarndy 1 well. The molecular and stable isotope data carbon and hydrogen will be used to understand the type of organic matter being preserved, the depositional facies and thermal maturity of the Lower Ordovician sedimentary rocks penetrated in this well. This information provides complementary information to other datasets including organic petrological and palynological studies.