GEORGINA BASIN—AN EARLY PALAEOZOIC CARBONATE PETROLEUM SYSTEM IN QUEENSLAND

2007 ◽  
Vol 47 (1) ◽  
pp. 107 ◽  
Author(s):  
J. Draper

Queensland contains a number of carbonate-bearing basins which are under-explored for petroleum, but contain the elements of potentially economic petroleum systems. The oldest such basin is the Neoproterozoic to Ordovician Georgina Basin which straddles the Queensland-Northern Territory border and is traversed by the Ballera to Mount Isa gas pipeline.The basin developed across several major crustal blocks resulting in regional variations in deposition and deformation. Thick Neoproterozoic rocks of the Centralian Superbasin form the base of the sequence in apparently fault-bounded, extensional sub-basins. These rocks are generally tight and source rocks are unknown. The Cambrian to Ordovician rocks have the best petroleum potential with the most prospective part of the basin being the Toko Syncline. The Burke River Structural Belt is less prospective, but is worthy of further exploration. Basin fill consists of Cambrian and Early Ordovician rocks which are dominantly carbonates, with both limestones and dolostones present. In the Early to Middle Ordovician, the rocks became predominantly siliciclastic.The main phase of deformation affecting the Georgina Basin occurred in the Devonian as part of the Alice Springs Orogeny. The Toomba Fault, which forms the western boundary of the asymmetric Toko Syncline, is a thrust fault with up to 6.5 km of uplift. The angle of thrusting is between less than 40 degrees and up to 70 degrees. Rich, marine source rocks of Middle Cambrian age in the Toko Syncline are mature for oil except in the deepest part of the syncline where they are mature for dry gas. The deeper part of the Toko Syncline may be gas saturated.Potential hydrocarbon targets include large folds associated with fault rollovers, stratigraphic traps and faultbounded traps. Vugular, secondary porosity in dolostones offers the best chance for commercial reservoirs within the Ninmaroo and Kelly Creek formations and Thorntonia Limestone. There are also oolitic carbonates which may have good primary porosity, as well as interbedded sandstones in the carbonates with preserved porosity. Structurally controlled hydrothermal dolomite facies represent potential reservoirs. The dominantly siliciclastic Ordovician sequence is water flushed. Fracture porosity is another possibility (cf. the Palm Valley gas field in the Amadeus Basin). As the deeper part of the Toko Syncline appears to be gas saturated, there may be potential for basin-centred gas. Fine-grained carbonates and shales provide excellent seals. There has not been a valid structural test; although AOD Ethabuka–1 flowed 7,000 m3/d of dry gas, the well was abandoned short of the target depth.

2019 ◽  
Vol 59 (2) ◽  
pp. 958
Author(s):  
Alison Troup ◽  
Behnam Talebi

The Devonian Adavale Basin system is an under-explored, frontier petroleum basin in south-west Queensland. It has a confirmed petroleum system with production from the Gilmore gas field. The age, marine depositional environments and high carbonate content suggest the basin may have unconventional petroleum potential, and there has been renewed interest from industry in evaluating the basin. In support of this, the Queensland Department of Natural Resources, Mines and Energy has examined the source rock properties of the Bury Limestone and Log Creek Formation and has commissioned an update to the SEEBASE® interpretation of the region. Gas- to oil-mature source rocks are found in deep marine shales of the Log Creek Formation, with secondary potential in the shelfal Bury Limestone. The main known reservoir within the Adavale Basin is the Lissoy Sandstone, though sandstones found in other units may also have tight reservoir potential. These petroleum systems elements form several plays, including conventional clastic structural targets, carbonate plays, including possible reef targets, and salt plays associated with doming from the Boree Salt. Potential unconventional targets include tight sandstone, shale and limestone, with recent analysis of an organic-rich marl from the Bury Limestone indicating good retention properties. The overlying Cooper, Galilee and Eromanga basins also contain potential reservoirs for hydrocarbons generated in the Adavale Basin and Warrabin Trough.


2016 ◽  
Vol 8 (1) ◽  
pp. 187-197 ◽  
Author(s):  
Iain C. Scotchman ◽  
Anthony G. Doré ◽  
Anthony M. Spencer

AbstractThe exploratory drilling of 200 wildcat wells along the NE Atlantic margin has yielded 30 finds with total discovered resources of c. 4.1×109 barrels of oil equivalent (BOE). Exploration has been highly concentrated in specific regions. Only 32 of 144 quadrants have been drilled, with only one prolific province discovered – the Faroe–Shetland Basin, where 23 finds have resources totalling c. 3.7×109 BOE. Along the margin, the pattern of discoveries can best be assessed in terms of petroleum systems. The Faroe–Shetland finds belong to an Upper Jurassic petroleum system. On the east flank of the Rockall Basin, the Benbecula gas and the Dooish condensate/gas discoveries have proven the existence of a petroleum system of unknown source – probably Upper Jurassic. The Corrib gas field in the Slyne Basin is evidence of a Carboniferous petroleum system. The three finds in the northern Porcupine Basin are from Upper Jurassic source rocks; in the south, the Dunquin well (44/23-1) suggests the presence of a petroleum system there, but of unknown source. This pattern of petroleum systems can be explained by considering the distribution of Jurassic source rocks related to the break-up of Pangaea and marine inundations of the resulting basins. The prolific synrift marine Upper Jurassic source rock (of the Northern North Sea) was not developed throughout the pre-Atlantic Ocean break-up basin system west of Britain and Ireland. Instead, lacustrine–fluvio-deltaic–marginal marine shales of predominantly Late Jurassic age are the main source rocks and have generated oils throughout the region. The structural position, in particular relating to the subsequent Early Cretaceous hyperextension adjacent to the continental margin, is critical in determining where this Upper Jurassic petroleum system will be most effective.


Clay Minerals ◽  
1986 ◽  
Vol 21 (4) ◽  
pp. 459-477 ◽  
Author(s):  
M. W. Goodchild ◽  
J. H. McD. Whitaker

AbstractThe diagenetic history of the Rotliegendes Sandstone reservoir in the Rough Gas Field was studied using thin-sections, XRD analyses and SEM. The Rotliegendes comprises a sequence of fine-grained fluvial sheet-flood sandstones and coarse, gravelly, low-sinuosity channel sandstones, with thin aeolian interbeds, overlain by a sequence of aeolian dune and interdune sandstones. Early, environmentally-related diagnesis (eogenesis) shows a marked variability with sedimentary facies. Within aeolian sandstones, poikilotopic anhydrite and fine, rhombic dolomite are preserved. Fluvially-derived sandstones typically contain infiltrated detrital clays and early authigenic mixed-layer clays, together with coarse, framework-displacive dolomite. Feldspars show varying degrees of alteration within all facies. These eogenetic features reflect patterns of groundwater movement during the Rotliegendes and early Zechstein. Mineral dissolution and precipitation were controlled by the chemistry of the groundwaters. Burial diagenetic (mesogenetic) features are superimposed on eogenetic cements. Authigenic clays have been converted to illitic clays. In addition, mesogenetic chlorite has formed and quartz and strongly ferroan dolomite cements are recognized. These minerals may be related to clay diagenesis within the underlying Carboniferous Coal Measures. Early, framework-supporting anyhdrite, and both phases of dolomite, have been partially dissolved, creating secondary porosity. This is attributed to the action of acidic porewaters, generated by the maturation of organic material within the Carboniferous. Post-dissolution kaolinite, gypsum and minor pyrite infill secondary pores. Gas emplacement from the Late Cretaceous onwards effectively halted further diagenetic reactions.


1990 ◽  
Vol 30 (1) ◽  
pp. 137 ◽  
Author(s):  
W.R. Lodwick ◽  
J.F. Lindsay

The Georgina Basin formed as a shallow intracratonic depression on the Australian craton along with a number of other basins in the Proterozoic and early Palaeozoic, probably in response to the break up of the Proterozoic supercontinent. Since all of these basins evolved under similar tectonic and sea-level controls, the basins all have similar sediment successions and, it might thus be assumed, similar petroleum prospectivity. One basin, the Amadeus Basin, currently has petroleum production, suggesting a potential for exploration success in the other intracratonic basins.In the Amadeus Basin the main petroleum prospects lie within or adjacent to major sub-basins that formed along the Basin's northern margin. The Georgina Basin has sub-basins that formed along its southern margin, almost as a mirror image of the Amadeus Basin. The lower Palaeozoic section of the Toko Syncline in the southern Georgina Basin has hydrocarbon shows in Middle Cambrian to Middle Ordovician rocks. Source rocks appear to have developed within the transgressive systems tract and the condensed interval of the highstand systems tract, at times when the basin was starved for clastic sediments and carbonate production was restricted.Seismic data acquired in the 1988 survey are of a higher quality than that previously obtained in the area. Its interpretation portrays the westward thrusting French Fault at the eastern edge of the Toko Syncline with potential hangingwall and footwall traps. Cambro- Ordovician Georgina Basin sediments subcrop the overlying Eromanga Basin with angularity, providing potentially large stratigraphic traps. Fracturing of the Cambrian and Ordovician carbonates within fault zones, and solution porosity at the unconformity, would also enhance reservoir potential in the area. Perhaps most significantly, the new data also shows an earlier, apparently independent basin completely buried beneath the Georgina section. The concealed section may simply be a very thick, early Upper Proterozoic section, or perhaps an equivalent to, or a lateral extension of the McArthur Basin. Recent work in the McArthur Basin has shown considerable source potential in the McArthur and Roper Groups, which may support the possibility of an additional, as yet unrecognised, source beneath the Georgina Basin.


2012 ◽  
Vol 52 (1) ◽  
pp. 525
Author(s):  
Margaret Hildick-Pytte

Recent investigation, including mapping re-processed seismic data, suggests there is deeper hydrocarbon potential in the WA-442-P and NT/P81 exploration permits beneath the Early Carboniferous Tanmurra Formation horizon. Earlier interpretation of the area showed tilted fault blocks commonly thought of as economic basement in the vicinity of the Turtle and Barnett oil fields and extending to the northwest to connect with the Berkley Platform. The deep-gas play type is structural and is believed to be two nested three-way dip anticlines developed against a large bounding fault to the northeast, with axial trends northwest to southeast, and axial plane curving towards the northeast for the deeper structure. This play type is believed to be associated with structural compression and movement along the master fault with incremental re-activation most recently during the Cainozoic as recorded in overlying sediments. The Nova Structure and the deeper Super Nova structure have closures of about 450 and 550 km2, respectively. The sediments beneath the Nova horizon are believed to be of Devonian Frasnian-Famennian age but have not been drilled offshore in the Southern Bonaparte Basin (Petrel Sub-basin). Earlier work suggests that there are two petroleum systems present in the southern Bonaparte Basin, a Larapintine source from Early Palaeozoic Devonian to Lower Carboniferous source rocks, and a transitional Larapintine/Gondwana system sourced from Lower Carboniferous to Permian source rocks. Hydrocarbon charge for the structures is most likely from the Larapintine source rock intervals or yet to be identified older intervals associated with the salt deposition during the Ordovician and Silurian. Independent estimates place close to 7 TCF (trillion cubic feet) of gas in the Nova Structure. New 3D seismic data acquisition is planned over the structures to better define the geology and ultimately delineate well locations.


1998 ◽  
Vol 38 (1) ◽  
pp. 380 ◽  
Author(s):  
X.W. Sun

The Early Palaeozoic eastern Warburton Basin unconformably underlies the Cooper and Eromanga Basins. Four seismic sequence sets (I−IV) are interpreted. Among them, sequence set II is subdivided into four Cambro-Ordovician depositional sequences. Sequence 1, the oldest, is a shallow shelf deposit that occurs only in the Gidgealpa area. Sequences 2 and 3 were deposited in a wider area; from west to east, environments varyied from deep siliciclastic ramp, carbonate inner-shelf, peritidal, shelf edge, and slope-to-basin. Their seismic reflection configurations are high-amplitude, regionally parallel-continuous, layered patterns, locally mounded geometry, as well as divergent-fill patterns. Sequence 4, the youngest, was deposited in a mixed siliciclastic and carbonate, storm-dominate shelf. Its seismic reflection configurations are moderate amplitude, parallel-layered patterns, decreasing in amplitude upwards.Boundaries between the four sequences generated good secondary porosity in the carbonates. Karst development is interpreted to have generated much of this porosity in shelf and peritidal carbonates, and carbonate build-ups. Shoal-water sandy limestone and calcareous sandstone of Sequence 4 may be other potential reservoir rocks. Potential source rocks comprise mudstone and shale of slope and basin lithofacies. There are two kinds of stratigraphic trap. One is in Sequences 2 and 3, associated with high-relief carbonate build-ups encased in lagoonal mudstone and shelf edge sealed by transgressive siltstone and shale. The other is a transgressive marine shale enclosing porous dolostone of the karstified Sequence 1. In addition, petroleum may have migrated from Permian source rocks of the Cooper Basin to karstified carbonate reservoirs of the Warburton Basin at unconformities.


1994 ◽  
Vol 34 (1) ◽  
pp. 692 ◽  
Author(s):  
Roger E. Summons ◽  
Dennis Taylor ◽  
Christopher J. Boreham

Maturation parameters based on aromatic hydrocarbons, and particularly the methyl-phenanthrene index (MPI-1), are powerful indicators which can be used to define the oil window in Proterozoic and Early Palaeozoic petroleum source rocks and to compare maturities and detect migration in very old oils . The conventional vitrinite reflectance yardstick for maturity is not readily translated to these ancient sediments because they predate the evolution of the land plant precursors to vitrinite. While whole-rock geochemical tools such as Rock-Eval and TOC are useful for evaluation of petroleum potential, they can be imprecise when applied to maturity assessments.In this study, we carried out a range of detailed geochemical analyses on McArthur Basin boreholes penetrating the Roper Group source rocks. We determined the depth profiles for hydrocarbon generation based on Rock-Eval analysis of whole-rock, solvent-extracted rock, kerogen elemental H/C ratio and pyrolysis GC. Although we found that Hydrogen Index (HI) and the Tmax parameter were strongly correlated with other maturation indicators, they were not sufficiently sensitive nor were they universally applicable. Maturation measurements based on saturated biomarkers were not useful either because of the low abundance of these compounds in most Roper Group bitumens and oils.


Georesursy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 78-84
Author(s):  
Anna A. Suslova ◽  
Antonina V. Stoupakova ◽  
Alina V. Mordasova ◽  
Roman S. Sautkin

Barents Sea basin is the most explored and studied by the regional and petroleum geologists on the Russian Arctic shelf and has approved gas reserves. However, there are many questions in the petroleum exploration, one of them is the structural reconstruction. During its geological evolution, Barents Sea shelf was influenced by the Pre-Novaya Zemlya structural zone that uplifted several times in Mesozoic and Cenozoic. The main goal of the research is to clarify the periods of structural reconstructions of the Eastern Barents shelf and its influence on the petroleum systems of the Barents Sea shelf. A database of regional seismic profiles and offshore borehole data collected over the past decade on the Petroleum Geology Department of the Lomonosov Moscow State University allows to define main unconformities and seismic sequences, to reconstruct the periods of subsidence and uplifts in Mesozoic and Cenozoic. The structural reconstructions on the Eastern Barents Sea in the Triassic-Jurassic boundary led to intensive uplifts and formation of the huge inversion swells, which is expressed in erosional truncation and stratigraphic unconformity in the Upper Triassic and Lower Jurassic strata. In the Jurassic period, tectonic subsidence reigned on the shelf, when the uplifts including the highs of Novaya Zemlya were partially flooded and regional clay seal and source rocks – Upper Jurassic «black clays» – deposited on the shelf. The next contraction phase manifested itself as a second impulse of the growth of inversion swells in the Late Jurassic-Early Cretaceous. Cenozoic uplift of the Pre-Novaya Zemlya structural zone and the entire Barents Sea shelf led to significant erosion of the Mesozoic sediments, on the one hand, forming modern structural traps, and on the other, significantly destroying the Albian, once regional seal.


Georesursy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 32-38
Author(s):  
Tatyana V. Karaseva ◽  
Yury A. Yakovlev ◽  
Galina L. Belyaeva ◽  
Svetlana E. Bashkova

This article is devoted to the problem of studying the petroleum potential of the underexplored territories of the European part of Russia, in particular, the Vychegda trough. Taken a new approach to assessing the hydrocarbon potential of the Vychegda trough, based on the allocation of petroleum systems, widely used abroad. Based on a comprehensive analysis of the geological structure of the deflection and geological-geochemical results, including those obtained by the authors, two potential petroleum systems – “domanic” and “riphean” – were identified. The potential domanic petroleum system dominates in the Eastern regions and is a peripheral fragment of the regional petroleum system covering the territory of the Volga-Ural and Timan-Pechora basins. The system is linked to development in the South-Eastern part of the trough and the neighbouring Solikamsk depression of bituminous domanic and domanicoid sediments as a source rock, which is confirmed by the genetic correlation of crude oils of Devonian-Carboniferous deposits of the Northern districts of Solikamsk depression with domanic biomarker. The stratigraphic range of the domanic system is upper Devonian-upper Permian; the formation time is late Devonian-Mesozoic. The potential Riphean hydrocarbon system can be identified by the fact of oil-bitumen occurrences in the Proterozoic strata and the presence of the productive source rocks in the upper Riphean. The source rocks were at oil window. The Riphean system can cover the entire territory of the Vychegda trough, and the section from the Riphean to upper Permian sediments. The time of the system formation – Riphean-Mesozoic. Due to large thickness of the Riphean sediments, even with a large loss of hydrocarbon potential, the residual potential hydrocarbon resources of the Riphean petroleum system can be very significant. Based on the research conducted, prioritized exploration studies are substantiated.


1998 ◽  
Vol 38 (1) ◽  
pp. 278 ◽  
Author(s):  
J.D. Alder ◽  
C. Bembrick ◽  
B. Hartung-Kagi ◽  
B. Mullard ◽  
D.A. Pratt ◽  
...  

New data, including regional high resolution aeromagnet ic coverage, acquired by the New South Wales Department of Mineral Resources (DMR) as part of its Discovery 2000 Initiative, have provided the first opportunity for a comprehensive review of the regional framework of the Darling Basin. Covering an area of 90,000 km2 in central western NSW, the Darling Basin contains over 8,000 m of mainly Palaeozoic sediments. With only 17 petroleum wells drilled in the basin, mostly during the 1960s and 1970s, and some 1,550 km of modern multifold seismic coverage, the Darling Basin represents one of the major frontier basinal regions of onshore Australia.The initial phase of petroleum exploration was discouraged by the lack of shows, the likelihood of gas-prone source rocks and presence of a thick, red-bed dominated, organically lean, Late Devonian sequence. Renewed interest in the Darling Basin's prospectivity followed from favourable, albeit superficial, comparisons between the Darling Basin and Queensland's Adavale Basin, where commercial gas is produced at the Gilmore Gas Field. Additionally, as part of some $15 million expenditure by the DMR on acquiring new and reassessing old data from the Darling Basin, new geochemical analyses of extracts collected from core holes and out-crop suggest the presence of at least one active Palaeozoic petroleum system. This system has been responsible for generating oil and possibly substantial quantities of gas found dissolved within artesian waters in the overlying shallow Mesozoic sequences.


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