AN ASSESSMENT OF THE ONSHORE PETROLEUM POTENTIAL OF CENTRAL AND SOUTH AUSTRALIA

1975 ◽  
Vol 15 (2) ◽  
pp. 60
Author(s):  
S. Bevan Devine
Keyword(s):  
Early Stage ◽  
South Australia ◽  
Gas Oil ◽  
Petroleum Potential ◽  
High Reward ◽  
Fault Structures ◽  
Great Attraction ◽  
Oil Deposits ◽  
Exploration Area ◽  
Cooper Basin

THE AMADEUS. Arrowie, Officer and Warburton Basins contain pre-Permian sediments with petroleum potential. The Cooper and Pedirka Basins have petroleum potential in Permian sediments. The Murray Basin contains Devonian. Permian and Cretaceous sediments with some potential.The Cooper Basin has established reserves of 6.5 t.c.f. raw gas in place in 16 fields from which Adelaide and Sydney markets will be served. Another seven small or unassessed fields have been discovered. Further exploration should probably double the established reserves. Wildcat drilling success is 1 in 3 so far.The Pedirka Basin is in an early stage of exploration. The geological elements of good sandstone reservoir beds, coaiy source beds, fold and fault structures and geological history analogous to the Cooper Basin gives it great attraction to the explorationist.The Amadeus Basin is an established petroleum province with gas and gas/oil deposits established in the enormous fold structures of the Palm Valley and Mereenie Fields respectively. Further prospects remain to be drilled but prior to drilling a market must be established for these resources which are in the centre of the Continent.Many geological and geophysical features of the Officer Basin are analogous to the Amadeus Basin but it is virtually unexplored. The basin is a high cost, high risk, possible high reward exploration area.

REVIEW OF THE PALAEOZOIC STRATIGRAPHY AND PETROLEUM POTENTIAL OF NORTHERN SOUTH AUSTRALIA

1975 ◽  
Vol 15 (1) ◽  
pp. 45
Author(s):  
S. B. Devine ◽  
B. C. Youngs
Keyword(s):  
South Australia ◽  
Oil Fields ◽  
Reservoir Rock ◽  
Petroleum Potential ◽  
Reservoir Rocks ◽  
Block Area ◽  
Reservoir Potential ◽  
Rock Lithology ◽  
Cooper Basin

The Amadeus, Warburton, Officer, Adavale, Arckaringa, Pedirka, Cooper and Great Artesian Basins form a complex system of overlapping basins in central Australia. Cambrian rocks are widespread in the Amadeus, Warburton and possibly the Officer Basins and are marked by the major role of carbonate deposition. Gas and oil shows are known from the Amadeus and Warburton Basins. In South Australia their reservoir potential lies in shoreline clean-up of generally dirty marine sandstones and porosity-permeability associated with archaeocyathid bioherms or dolomitization of limestones.The Ordovician rocks follow the widespread distribution of the Cambrian rocks and are distinctive for thick quartzites and graptolitic shales. In South Australia, the Warburton and Officer Basins may have facies developed which are similar to the Pacoota and Stairway Sandstones, the reservoir rocks for the Amadeus Basin gas and oil fields. Large anticlinal structures have recently been suggested by S.A. Mines Department geophysical work in the Officer Basin which enhances the potential.Red beds are distinctive in the Devonian System. Deposition apparently spilt into the peri-Musgrave Block area and the Adavale Basin to Innamincka area. A thickness of over 3 000 metres of Devonian rocks was drilled in the Officer Basin which contained some reservoir rock lithology. The petroleum potential in South Australia is relatively unattractive.Some 3.4 trillion cu ft of deliverable gas reserves have been established already in the Permian sediments of the Cooper Basin which are up to 900 m thick. The Early Permian sediments of the Pedirka Basin which may be at least 500 m thick may hold similar petroleum potential.

PETROLEUM GENERATION AND SOURCE ROCK ASSESSMENT IN TERRIGENOUS SEQUENCES: AN UPDATE

1991 ◽  
Vol 31 (1) ◽  
pp. 297 ◽  
Author(s):  
T.G. Powell ◽  
C.J. Boreham
Keyword(s):  
Elemental Composition ◽  
Source Rock ◽  
Early Stage ◽  
Source Rocks ◽  
Simple Relationship ◽  
Petrographic Composition ◽  
Petroleum Potential ◽  
Lower Ratio ◽  
Coal Measures ◽  
Cooper Basin

Analytical pyrolysis and sealed tube pyrolysis at low temperatures have been used to study the timing and petroleum generating capacity of selected Permian through Tertiary coals and carbonaceous shales in relation to their petrographic and elemental composition. The results show that judicious application of flash pyrolysis techniques in conjunction with more conventional procedures are essential for effective source rock assessment in terrigenous source rocks, particularly in those of lower quality.Although the petroleum potential of the samples follows the broad trends in petrographic composition established for Australian coals, that is, relative proportions of vitrinite, inertinite and liptinite, there is much variation which cannot be explained petrographically at the maceral group level. Furthermore, there is no simple relationship between pyrolytic hydrocarbon yield from terrigenous kerogens and overall elemental composition. The yield and composition of pyrolysable normal hydrocarbons varies widely depending on the nature and amount of liptinite macerals, particularly for samples with Hydrogen Indices below 300. Liptinite-poor (Mass balance calculations based on Rock-Eval analyses of samples from the Jurassic Walloon Coal Measures show that the maximum oil formation occurs over a very narrow maturation window from 0.8 to 1.0 per cent Ro, although small amounts of oil may be generated at lower maturation levels. The gas to oil ratio of the generated hydrocarbons is constant up to a reflectance level of 1.0 per cent Ro, where upon the proportion of gas increases rapidly. The low quality Permian source rocks from the Cooper Basin have a lower ratio of labile to refractory kerogen than the Jurassic and Tertiary examples. As a result, the gas to oil ratio of hydrocarbons formed in the oil window is higher and the oil potential appears to be exhausted at an earlier stage of maturation. Efficient migration of hydrocarbons from Permian sediments in the Cooper Basin also appears to occur at a relatively early stage of maturation compared with the Jurassic Walloon Coal Measures.

Exploring for stratigraphic traps in the Patchawarra Formation, Cooper Basin: an integrated seismic methodology

2018 ◽  
Vol 58 (2) ◽  
pp. 779
Author(s):  
Alexandra Bennett
Keyword(s):  
Complex Geometry ◽  
Imaging Techniques ◽  
South Australia ◽  
Seismic Interpretation ◽  
Seismic Survey ◽  
3D Seismic ◽  
Seismic Resolution ◽  
Seismic Reflectivity ◽  
Seismic Area ◽  
Cooper Basin

The Patchawarra Formation is characterised by Permian aged fluvial sediments. The conventional hydrocarbon play lies within fluvial sandstones, attributed to point bar deposits and splays, that are typically overlain by floodbank deposits of shales, mudstones and coals. The nature of the deposition of these sands has resulted in the discovery of stratigraphic traps across the Western Flank of the Cooper Basin, South Australia. Various seismic techniques are being used to search for and identify these traps. High seismic reflectivity of the coals with the low reflectivity of the relatively thin sands, often below seismic resolution, masks a reservoir response. These factors, combined with complex geometry of these reservoirs, prove a difficult play to image and interpret. Standard seismic interpretation has proven challenging when attempting to map fluvial sands. Active project examples within a 196 km2 3D seismic survey detail an evolving seismic interpretation methodology, which is being used to improve the delineation of potential stratigraphic traps. This involves an integration of seismic processing, package mapping, seismic attributes and imaging techniques. The integrated seismic interpretation methodology has proven to be a successful approach in the discovery of stratigraphic and structural-stratigraphic combination traps in parts of the Cooper Basin and is being used to extend the play northwards into the 3D seismic area discussed.

The Scoresbysund rifted margin composite TSE offshore central East Greenland

2021 ◽  
pp. M57-2017-43
Author(s):  
Michael B. W. Fyhn
Keyword(s):  
Source Rock ◽  
Petroleum Potential ◽  
East Greenland ◽  
Fan Delta ◽  
Geological Evolution ◽  
Major Fault ◽  
Fault Structures ◽  
Greenland Margin ◽  
Rifted Margin ◽  
Thermal Subsidence

AbstractThe little explored central East Greenland margin contains thick sedimentary accumulations confined within the Scoresbysund Basin. The geological evolution of the area distinguishes from other parts of East Greenland. Even so, resemblances with the prospective basins onshore and offshore farther north probably exist, and the margin may hold a real petroleum potential. The Scoresbysund Rifted Margin Composite Tectonic-Sedimentary Element delineates the oldest part of the Scoresbysund Basin. It formed through multiple phases of rifting, volcanism, uplift and thermal subsidence between Devonian and Miocene time. The development of the composite tectonic-sedimentary element concluded with the latest Oligocene or early Miocene continental break-up of the Jan Mayen microcontinent and East Greenland. The Scoresbysund Rifted Margin Composite Tectonic-Sedimentary Element contains approximately 4 km of Eocene-lower Miocene fan-delta deposits that accumulated during down-faulting along the East Greenland Escarpment and farther seawards intercalate with basalts. The fan-delta deposits rest on Paleocene basalts that most likely cover Paleozoic-Mesozoic strata. Equivalent to onshore, the deeply buried section probably include source rock and reservoir intervals of Carboniferous, Permian and Mesozoic age. Together with the major fault structures existing in the western part of the area, this may form the basis for a working petroleum system.

HIGH RESOLUTION PALAEOGEOGRAPHIC MAPPING OF THE FLUVIAL-LACUSTRINE PATCHAWARRA FORMATION IN THE COOPER BASIN, SOUTH AUSTRALIA

2002 ◽  
Vol 42 (1) ◽  
pp. 65 ◽  
Author(s):  
P.C. Strong ◽  
G.R. Wood ◽  
S.C. Lang ◽  
A. Jollands ◽  
E. Karalaus ◽  
...  
Keyword(s):  
High Resolution ◽  
South Australia ◽  
River System ◽  
Structural Features ◽  
Gas Reservoirs ◽  
Predictive Tool ◽  
Sequence Stratigraphic ◽  
Channel Belt ◽  
Reservoir Connectivity ◽  
Cooper Basin

Fluvial-lacustrine reservoirs in coal-bearing strata provide a particular challenge for reservoir characterisation because of the dominance of coal on the seismic signature and the highly variable reservoir geometry, quality and stratigraphic connectivity. Geological models for the fluvial gas reservoirs in the Permian Patchawarra Formation of the Cooper Basin are critical to minimise the perceived reservoir risks of these relatively deep targets. This can be achieved by applying high-resolution sequence stratigraphic concepts and finescaled seismic mapping. The workflow begins with building a robust regional chronostratigraphic framework, focussing on widespread lacustrine flooding surfaces and unconformities, tied to seismic scale reflectors. This framework is refined by identification of local surfaces that divide the Patchawarra Formation into high-resolution genetic units. A log facies scheme is established based on wireline log character, and calibrated to cores and cuttings, supported by analogue studies, such as the modern Ob River system in Western Siberia. Stacking patterns within each genetic unit are used to determine depositional systems tracts, which can have important reservoir connectivity implications. This leads to the generation of log signature maps for each interval, from which palaeogeographic reconstructions are generated. These maps are drawn with the guiding control of syn-depositional structural features and net/ gross trends. Estimates of fluvial channel belt widths are based on modern and ancient analogues. The resultant palaeogeography maps are used with structural and production data to refine play concepts, as a predictive tool to locate exploration and development drilling opportunities, to assess volumetrics, and to improve drainage efficiency and recovery during production of hydrocarbons.

EXPLORATION IN THE COOPER BASIN

1989 ◽  
Vol 29 (1) ◽  
pp. 366 ◽  
Author(s):  
R. Heath
Keyword(s):  
Oil And Gas ◽  
South Australia ◽  
Mature Stage ◽  
Small Contribution ◽  
Terrestrial Source ◽  
Seismic Acquisition ◽  
Proterozoic Basement ◽  
Gas Fields ◽  
Coal Measures ◽  
Cooper Basin

The Cooper Basin is located in the northeastern corner of South Australia and in the southwestern part of Queensland. The basin constitutes an intracratonic depocentre of Permo- Triassic age. The Cooper Basin succession unconformably overlies Proterozoic basement as well as sediments and metasediments of the Cambro- Ordovician age. An unconformity separates in turn the Cooper succession from the overlying Jurassic- Cretaceous Eromanga Basin sediments.The Permo- Triassic succession comprises several cycles of fluvial sandstones, fluvio- deltaic coal measures and lacustrine shales. The coal measures contain abundant humic kerogen, comprising mainly inertinite and vitrinite with a small contribution of exinite. All hydrocarbon accumulations within the Cooper Basin are believed to have originated from these terrestrial source rocks.Exploration of the basin commenced in 1959 and, after several dry holes, the first commercial discovery of gas was made at Gidgealpa in 1963. To date, some 97 gas fields and 10 oil fields, containing recoverable reserves of 5 trillion cubic feet of gas and 300 million barrels recoverable natural gas liquids and oil, have been discovered in the Cooper Basin. Production is obtained from all sand- bearing units within the Cooper stratigraphic succession.The emphasis of exploration in the Cooper Basin is largely directed towards the assessment of four- way dip closures and three- way dip closures with fault control, but several stratigraphic prospects have been drilled. Furthermore, in the development phase of some gas fields a stratigraphic component of the hydrocarbon trapping mechanism has been recognised.Improvements in seismic acquisition and processing, combined with innovative thinking by the explorers, have facilitated the development of untested structural/stratigraphic plays with large reserves potential. Exploration for the four- and three- way dip closure plays in the Cooper Basin is now at a mature stage. However, reserves objectives are expected to continue to be met, with the expectation of a continuing high success rate.Selected new plays are expected to be tested within a continuing active exploration program as exploration for oil and gas in the Cooper Basin refines the search for the subtle trap.

A REVIEW OF RECENT GEOLOGICAL WORK IN THE OFFICER BASIN, SOUTH AUSTRALIA

1980 ◽  
Vol 20 (1) ◽  
pp. 209 ◽  
Author(s):  
G.M. Pitt ◽  
M.C. Benbow ◽  
Bridget C. Youngs
Keyword(s):  
South Australia ◽  
Source Rocks ◽  
Organic Carbon Content ◽  
Petroleum Potential ◽  
Geological Surveys ◽  
Potential Source ◽  
Potential Reservoir ◽  
Carbonate Sequence ◽  
Geological Work ◽  
Australian Department

The Officer Basin of South and Western Australia, in its broadest definition, contains a sequence of Late Proterozoic to pre-Permian strata with an unknown number of stratigraphic breaks. Recent investigations by the South Australian Department of Mines and Energy (SADME), which included helicopter-based geological surveys and stratigraphic drilling, have upgraded the petroleum potential of the basin.SADME Byilkaoora-1, drilled in the northeastern Officer Basin in 1979, contained hydrocarbon shows in the form of oil exuding from partly sealed vugs and fractures in argillaceous carbonates. Equivalent carbonates were intersected in SADME Marla-1A and 1B. Previously, in 1976, SADME Murnaroo-1 encountered shales and carbonates with moderate organic carbon content overlying a thick potential reservoir sandstone, while SADME Wilkinson-1, drilled in 1978, contained a carbonate sequence with marginally mature to mature oil-prone source rocks. Acritarchs extracted from the last mentioned carbonates indicate an Early Cambrian age.All ?Cambrian carbonate sequences recognised to date in the Officer Basin of South Australia are correlated with the Observatory Hill Beds, which are now considered to be the major potential source of petroleum in the eastern Officer Basin.

A SEISMIC MODEL OF FAULTS IN THE COOPER BASIN

1984 ◽  
Vol 24 (1) ◽  
pp. 421
Author(s):  
R. J. Gray ◽  
D. C. Roberts
Keyword(s):  
Hanging Wall ◽  
South Australia ◽  
Shadow Zone ◽  
Seismic Line ◽  
Seismic Section ◽  
Seismic Modelling ◽  
Geological Cross Section ◽  
Major Fault ◽  
Seismic Lines ◽  
Cooper Basin

A synthetic seismic section was modelled to help in the interpretation of Cooper Basin seismic lines which cross major faults and exhibit shadow zones.A major fault bounding the northwest flank of the Packsaddle Structure in the Merrimelia-Innamincka Farmout Block in South Australia was selected for modelling. A geological cross-section postulated on the basis of wells on either side of the fault was fed into the seismic modelling package AIMS (Advanced Interpretive Modelling System — licensed by Geoquest International Inc.) to produce a synthetic seismic line. This synthetic line provided a realistic match with an actual seismic line across the fault. Pre-stack migration of the actual seismic data is suggested to provide additional evidence for the reliability of the model.The shadow zone in the synthetic section is caused by dipping events in the fault shadow zone created by compaction of the Toolachee and Patchawarra Formations along the hanging wall of the fault plane. The dipping events cause reflected energy to be detected outside the fault zone. The large component of compaction within the Permian section is largely ascribed to thick coal horizons. The possibility of petroleum traps in the hanging wall of the fault is inferred and drilling is recommended.

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