Bight Basin acreage release—new exploration opportunities in a deep water frontier

2009 ◽  
Vol 49 (1) ◽  
pp. 491
Author(s):  
Jennifer Totterdell ◽  
Heike Struckmeyer ◽  
Andrew Stacey
Keyword(s):  
Late Cretaceous ◽  
Seismic Data ◽  
Source Rocks ◽  
High Quality ◽  
Reservoir Rocks ◽  
Potential Source ◽  
Exploration Risk ◽  
Commonwealth Government ◽  
Exploration Drilling ◽  
Water Depths

In 2009, the Commonwealth Government is releasing six large exploration areas in the frontier Bight Basin. The areas lie in the Ceduna Sub-basin, in water depths ranging from 130 to 4,600 m. At present, no permits are held in this part of the basin. Most exploration drilling in the Bight Basin has focussed on the margins of the Ceduna Sub-basin and on the adjacent Duntroon Sub-basin. Gnarlyknots 1A, drilled by Woodside Energy and partners in 2003, is the only well to have attempted to test the thick, prospective Ceduna Sub-basin succession away from the margins of the sub-basin, but did not reach all its target horizons due to weather and ocean conditions. The key to the petroleum prospectivity of the Ceduna Sub-basin is the distribution of the Late Cretaceous marine and deltaic facies. Recent dredging of Late Cenomanian–Turonian organic-rich marine rocks has confirmed the presence of high quality source rocks in the Bight Basin and has significantly reduced exploration risk. These potential source rocks are mature in the central part of the Ceduna Sub-basin and are likely to have generated and expelled hydrocarbons since the Campanian. Excellent reservoir rocks and potential intraformational seals are present in the Late Cretaceous deltaic successions and regional seals could be provided by Late Cretaceous marine shales. Interpretation of seismic data has identified numerous play types in the basin and some structures show amplitude anomalies, providing many exploration targets for explorers.

THE CEDUNA SUB-BASIN—A SNAPSHOT OF PROSPECTIVITY

2001 ◽  
Vol 41 (1) ◽  
pp. 321 ◽  
Author(s):  
R. Somerville
Keyword(s):  
Late Cretaceous ◽  
Seismic Data ◽  
Charge System ◽  
The North ◽  
Exploration Risk ◽  
Exploration Drilling ◽  
Marine Seismic ◽  
Hydrocarbon Charge ◽  
Great Australian Bight ◽  
Water Depths

The Ceduna Sub-basin comprises one of the major untested potential petroleum provinces in Australia. It is located in the Great Australian Bight, forming part of the Bight Basin. Water depths range from 100 m in the north to over 4,000 m in the south. Although over 100,000 line km of 2D marine seismic data have been acquired in the Great Australian Bight, only 20,600 line km of 2D marine seismic data of variable vintage and quality have been acquired in the Ceduna Sub-basin. Only one exploration well, Potoroo–1, has been drilled within the Ceduna Sub-basin. The Potoroo–1 well is located on the extreme landward edge of the depocentre which is dominated by the Late Cretaceous Ceduna Delta. Consequently, the hydrocarbon potential of the basin is effectively untested.The most promising play types within the Ceduna Subbasin are dip and fault-dip closures associated with listric faults within the Late Cretaceous (Santonian- Maastrichtian) deltaic sequence and accentuated by slight Late Cretaceous/Tertiary compression. Fault-dip closures are also recognised within the Santonian section. A channel sub-crop play within the Santonian is also potentially viable.Hydrocarbon charge is perceived to be the most significant exploration risk. Although asphaltite strandings have been reported, the hydrocarbon charge system is unproven. Future exploration in the Great Australian Bight will need to address:harsh climatic/meteorological and oceanographic conditions in the Southern Ocean and short seasonal windows;extreme sea floor relief and viability of safe exploration drilling in water depths over 1,500 m; andoperating in a responsible and environmentally sensitive way in proximity to the Benthic Protection Zone.

THE GEOLOGY AND EVOLUTION OF THE SCOTT PLATEAU

1978 ◽  
Vol 18 (1) ◽  
pp. 34 ◽  
Author(s):  
H. M. J. Stagg
Keyword(s):  
Seismic Data ◽  
Seismic Reflection ◽  
Structural Evolution ◽  
Source Rocks ◽  
Petroleum Potential ◽  
Reservoir Rocks ◽  
Carbonate Sedimentation ◽  
Sea Bed ◽  
Adjacent Part ◽  
Water Depths

The Scott Plateau and the adjacent Rowley Terrace cover about 130,000 km2 beyond Australia's Northwest Shelf in water depths ranging from 300 m to 3000 m. The regional geology and structural evolution of the area have been interpreted from about 13,000 km of seismic reflection profiles.The Scott Plateau forms a subsided oceanward margin to the Browse Basin. For much of the period from the Carboniferous to the Middle Jurassic, preceding the breakup which formed this part of the continental margin, the Scott Plateau was probably above sea level shedding sediment into the developing Browse Basin. After breakup in the Bathonian to Callovian, the plateau subsided, until by the Late Cretaceous open marine conditions were prevalent over most of the area, with the probable exception of some structurally high areas which may have remained emergent until early in the Tertiary. Carbonate sedimentation commenced in the Santonian and has continued to the present, with major hiatuses in the Paleocene and Oligocene. Analysis of magnetic and seismic data indicates that, over much of the plateau, economic basement of possible Kimberley Block equivalents is probably no more than 3 to 4 km below sea bed. To the south of the Scott Plateau, the Rowley Terrace is underlain by a wedge of at least 6 km of Mesozoic and Tertiary sediments of the northeast- trending Rowley Sub - basin. The Rowley Sub -basin connects with the Beagle Sub-basin to the southwest and probably connects with the Browse Basin to the northeast. It has been largely unaffected by episodes of faulting, except in the southwest where faulting and folding are pronounced. The petroleum potential of the Scott Plateau is not rated highly. The potential hydrocarbon-bearing sediments here are probably no younger than Palaeozoic. These are quite likely to be only 2 to 4 km thick, and any hydrocarbons generated within them would probably have been lost during the protracted period of emergence and erosion that preceded breakup. The hydrocarbon potential appears to be greater in the Rowley Sub-basin, where Triassic to Cretaceous shale and siltstone source rocks, and Triassic to Lower Cretaceous sandstone reservoir rocks are expected to be present. However, the potential of these sequences is downgraded because hydrocarbon shows in exploration wells on the adjacent part of the Northwest Shelf have been only minor, and by the apparent scarcity of suitable traps. Exploitation of any hydrocarbons would be costly owing to the great water depths.

scholarly journals The Cambrian Henson Gletscher Formation: a mature to postmature hydrocarbon source rock sequence from North Greenland

1987 ◽  
Vol 133 ◽  
pp. 141-157
Author(s):  
F.G Christiansen ◽  
H Nøhr-Hansen ◽  
O Nykjær
Keyword(s):  
Source Rock ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Hydrocarbon Source Rock ◽  
Reservoir Rocks ◽  
Potential Source ◽  
Potential Reservoir ◽  
Field Season ◽  
North Greenland

During the 1985 field season the Cambrian Henson Gletscher Formation in central North Greenland was studied in detail with the aim of evaluating its potential as a hydrocarbon source rock. The formation contains organic rich shale and carbonate mudstone which are considered to be potential source rocks. These are sedimentologically coupled with a sequence of sandstones and coarse carbonates which might be potential reservoir rocks or migration conduits. Most of the rocks exposed on the surface are, however, thermally mature to postrnature with respect to hydrocarbon generation, leaving only few chances of finding trapped oil in the subsurface of the area studied in detail.

DEPOSITIONAL SEQUENCE OF THE WITHNELL FORMATION, DAMPIER SUB-BASIN

1995 ◽  
Vol 35 (1) ◽  
pp. 296
Author(s):  
J. S. Rasidi
Keyword(s):  
Late Cretaceous ◽  
Seismic Data ◽  
Depositional Environment ◽  
Thickness Distribution ◽  
Well Logs ◽  
Hydrocarbon Potential ◽  
Depositional Sequence ◽  
Well Data ◽  
Water Depths ◽  
Reservoir Facies

The Late Cretaceous Withnell Formation has attracted very little exploration attention because of the perception that it has poor hydrocarbon potential. This unfavourable perception has arisen from the fact that very little is known about its depositional environment and lithofacies and therefore, its petroleum prospectivity.A sudden fall of relative sea level occurred at the end of the Santonian, and was followed by the deposition of the siliciclastic Withnell Formation. The occurrence of a number of channels and canyons at the base of the formation, over the old shelf and slope on the southern margin of the sub-basin, supports the hypothesis that the Withnell Formation began as a lowstand systems tract. The thickness distribution of the formation and the progradation direction of seismic packages suggest a southeasterly provenance. Correlation of seismic data and well logs, and rock descriptions demonstrate the presence of units deposited during increasing water depths and subsequent highstand systems tract.Much more information, both seismic and well data, is required to establish the facies distribution within the Withnell Formation which may contain sand-prone lowstand facies such as basinfloor or slope fans. The presence of such reservoir facies would enhance the petroleum prospectivity of the Withnell Formation.

THE OFFSHORE CARPENTARIA BASIN-GULF OF CARPENTARIA, NORTH QUEENSLAND

1994 ◽  
Vol 34 (1) ◽  
pp. 614
Author(s):  
B.A. McConachie ◽  
P.W. Stainton ◽  
M.G. Barlow ◽  
J.N. Dunster
Keyword(s):  
Early Cretaceous ◽  
Seismic Data ◽  
Late Jurassic ◽  
Source Rocks ◽  
Low Velocity ◽  
Reservoir Rocks ◽  
Half Graben ◽  
Reservoir Sandstones ◽  
Cape York ◽  
Velocity Channel

The Carpentaria Basin is late Jurassic to early Cretaceous in age and underlies most of the Gulf of Carpentaria and surrounding onshore areas. The Carpentaria Basin is stratigraphically equivalent to the Eromanga and Papuan Basins where similar reservoir rocks produce large volumes of hydrocarbons.Drillholes Duyken–1, Jackie Ck–1 and 307RD12 provide regional lithostratigraphic and tectonic control for the Q22P permit in the offshore Carpentaria Basin. Duyken–1 penetrated the upper seal section in the Carpentaria Basin and a full sequence through the overlying Karumba Basin. Jackin Ck–1 intersected the lower reservoir units and a condensed upper seal section of the Carpentaria Basin. Coal drillhole 307RD12 tested the late Jurassic to early Cretaceous reservoir section in the Carpentaria Basin and also intersected an underlying Permian infrabasin sequence.Little is known of the pre Jurassic sedimentary section below the offshore Carpentaria Basin but at least two different rock packages appear to be present. The most encouraging are relatively small, layered, low velocity, channel and half-graben fill, possibly related to Permian or Permo-Triassic sedimentary rocks to the east in the Olive River area. The other packages consist of poorly defined, discontinuous, high velocity rocks believed to be related to those of the Bamaga Basin which have been mapped further north.During the period 1990-1993 Comalco Aluminium Limited reprocessed 2188 km of existing seismic data and acquired 2657 km of new seismic data over the offshore Carpentaria Basin. When combined with onshore seismic and the results of drilling previously undertaken by Comalco near Weipa on northwestern Cape York Peninsula, it was possible to define a significant and untested play in the Carpentaria Depression, the deepest part of the offshore Carpentaria Basin.The main play in the basin is the late Jurassic to early Cretaceous reservoir sandstones and source rocks, sealed by thick early Cretaceous mudstones. Possible pre-Jurassic source rocks are also present in discontinuous fault controlled half-grabens underlying the Carpentaria Basin. New detailed basin modelling suggests both the lower part of the Carpentaria Basin and any pre Jurassic section are mature within the depression and any source rocks present should have expelled oil.

Oil-oil correlation and potential source rocks for oils in Paleozoic reservoir rocks in the Tataria and Perm basins, Russia

1998 ◽  
Vol 29 (1-3) ◽  
pp. 701-712 ◽  
Author(s):  
Zeev Aizenshtat ◽  
Shimon Feinstein ◽  
Irena Miloslavski ◽  
Zoya Yakubson ◽  
Christof.I. Yakubson
Keyword(s):  
Source Rocks ◽  
Reservoir Rocks ◽  
Potential Source

PETROLEUM AND GEOLOGY: A SYNTHESIS

1972 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Richard E. Chapman
Keyword(s):  
Sediment Accumulation ◽  
Sedimentary Basins ◽  
Direct Consequence ◽  
Source Rocks ◽  
Reservoir Rocks ◽  
Subsurface Geology ◽  
Tectonic Events ◽  
Potential Source ◽  
Potential Reservoir ◽  
Vertical Gravity

A marine sedimentary basin typically begins with a transgressive phase and ends with a regressive phase; but there may be several cycles, and also periods in which neither is dominant.Petroleum occurrences fall into two broad stratigraphie classes: those of transgressive sequences, and those of regressive sequences. Transgressions tend to accumulate potential source rocks on top of potential reservoir rocks, and the petroleum tends to migrate downwards then laterally into stratigraphic traps, especially reefs and below unconformities. It also occurs in diachronous units that are anticlinal in form due to basement irregularities. Regressions tend to accumulate potential reservoir rocks on top of potential source rocks, and the petroleum tends to migrate upwards and then laterally into anticlines and fault traps that are typically initiated contemporaneously or penecontemporaneously with sediment accumulation. There is some evidence that oil of transgressive sequences is heavier than oil of regressive sequences.Evidence derived from subsurface geology, including petroleum occurrences, suggests that young marine sedimentary basins are typically deformed by vertical, gravity processes during and just after significant regressive phases of their development; and that these processes are a direct consequence of the accumulation of sediment in a regressive sequence. Subsequent horizontal tectonic events, in general, only modify the earlier, contemporaneous, deformation.

Petroleum Systems Analysis of The Tungkal PSC Area, South Sumatra – A Means of Adding New Life to A Mature Area

2020 ◽  
Author(s):  
A. Livsey
Keyword(s):  
Seismic Data ◽  
Systems Analysis ◽  
Generation Model ◽  
Hydrocarbon Accumulation ◽  
Petroleum Systems ◽  
Oil Generation ◽  
Exploration Risk ◽  
Exploration Area ◽  
Hydrocarbon Charge ◽  
Surface Geology

South Sumatra is considered a mature exploration area, with over 2500MMbbls of oil and 9.5TCF of gas produced. However a recent large gas discovery in the Kali Berau Dalam-2 well in this basin, highlights that significant new reserve additions can still be made in these areas by the re-evaluation of the regional petroleum systems, both by identification of new plays or extension of plays to unexplored areas. In many mature areas the exploration and concession award history often results in successively more focused exploration programmes in smaller areas. This can lead to an increased emphasis on reservoir and trap delineation without further evaluation of the regional petroleum systems and, in particular, the hydrocarbon charge component. The Tungkal PSC area is a good example of an area that has undergone a long exploration history involving numerous operators with successive focus on block scale petroleum geology at the expense of the more regional controls on hydrocarbon prospectivity. An improved understanding of hydrocarbon accumulation in the Tungkal PSC required both using regional petroleum systems analysis and hydrocarbon charge modelling. While the Tungkal PSC operators had acquired high quality seismic data and drilled a number of wells, these were mainly focused on improving production from the existing field (Mengoepeh). More recent exploration-driven work highlighted the need for a new look at the hydrocarbon charge history but it was clear that little work had been done in the past few year to better understand exploration risk. This paper summarises the methodology employed and the results obtained, from a study, carried out in 2014-15, to better understand hydrocarbon accumulation within the current Tungkal PSC area. It has involved integration of available well and seismic data from the current and historical PSC area with published regional paleogeographic models, regional surface geology and structure maps, together with a regional oil generation model. This approach has allowed a better understanding of the genesis of the discovered hydrocarbons and identification of areas for future exploration interest.

Stratigraphic Intervals for Oil and Tar Sand Deposits in the Uinta Basin, Utah

2017 ◽  
Vol 54 (4) ◽  
pp. 227-264
Author(s):  
Ronald Johnson ◽  
Justin Birdwell ◽  
Paul Lillis
Keyword(s):  
Brackish Water ◽  
Source Rocks ◽  
Uinta Basin ◽  
Green River ◽  
Reservoir Rocks ◽  
Stratigraphic Framework ◽  
Two Samples ◽  
The Rich ◽  
And Migration ◽  
Almost All

To better understand oil and bitumen generation and migration in the Paleogene lacustrine source rocks of the Uinta Basin, Utah, analyses of 182 oil samples and tar-impregnated intervals from 82 core holes were incorporated into a well-established stratigraphic framework for the basin. The oil samples are from the U.S. Geological Survey Energy Resources Program Geochemistry Laboratory Database; the tar-impregnated intervals are from core holes drilled at the Sunnyside and P.R. Spring-Hill Creek tar sands deposits. The stratigraphic framework includes transgressive and regressive phases of the early freshwater to near freshwater lacustrine interval of Lake Uinta and the rich and lean zone architecture developed for the later brackish-to-hypersaline stages of the lake. Two types of lacustrine-sourced oil are currently recognized in the Uinta Basin: (1) Green River A oils, with high wax and low β-carotane contents thought to be generated by source rocks in the fresh-to-brackish water lacustrine interval, and (2) much less common Green River B oils, an immature asphaltic oil with high β-carotane content thought to be generated by marginally mature to mature source rocks in the hypersaline lacustrine interval. Almost all oil samples from reservoir rocks in the fresh-to-brackish water interval are Green River A oils; however four samples of Green River A oils were present in the hypersaline interval, which likely indicates vertical migration. In addition, two samples of Green River B oil are from intervals that were assumed to contain only Green River A oil. Tar sand at the P.R. Spring-Hill Creek deposit are restricted to marginal lacustrine and fluvial sandstones deposited during the hypersaline phase of Lake Uinta, suggesting a genetic relationship to Green River B oils. Tar sand at the Sunnyside deposit, in contrast, occur in marginal lacustrine and alluvial sandstones deposited from the early fresh to nearly freshwater phase of Lake Uinta through the hypersaline phase. The Sunnyside deposit occurs in an area with structural dips that range from 7 to 14 degrees, and it is possible that some tar migrated stratigraphically down section.

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