PALAEOTECTONIC EVOLUTION AND HYDROCARBON GENESIS OF THE CENTRAL EXMOUTH PLATEAU

1982 ◽  
Vol 22 (1) ◽  
pp. 131 ◽  
Author(s):  
Peter M. Barber

In the wake of high industry optimism for the discovery of commercially viable hydrocarbons on the Exmouth Plateau, drilling of three wells by the Phillips Group revealed the presence of noncommercial quantities of gas. Expectations were originally based on the generation of oil from Upper Jurassic and Neocomian shales in the Kangaroo Trough and subsequent migration into Triassic and Jurassic tilted fault blocks on the Exmouth Plateau High, tested by the Jupiter 1 and Mercury 1 wells. In both these wells, and at the Saturn 1 location subsequently drilled in the Kangaroo Trough, the Upper Triassic, Jurassic and Cretaceous sections were found to be immature and incapable of generating hydrocarbons. Most hydrocarbon shows on the Exmouth Plateau possibly originated from a deep (5.5 km) overmature gas source, probably Lower Triassic and Permian shales. Deep tapping of the source beds by faults bounding the tilted fault block structures has enabled gas to migrate.Integrated palaeotectonic and thermal maturation studies indicate a direct link between the hydrocarbon grade and its subsequent expulsion and entrapment. The absence of much of the Jurassic cover due to erosion and/or non-deposition allowed early and mature phase hydrocarbons being generated from the Permian and Lower Triassic to escape. With increasing depth of burial and concomitant overmature hydrocarbon genesis during the Cenozoic era, further leakage was caused by upward perpetuation and regeneration of the fault conduits, breaching the Lower Cretaceous and younger sealing units. Effective trapping usually occurs only where overmature gas is trapped by fault-independent closure immediately beneath the Callovian break-up unconformity, such as at Jupiter 1 and Saturn 1.The lack of major liquid hydrocarbons is attributed to unfavourable source rocks, inadequate burial history and an historically low geothermal gradient, the effect of which is further compounded by the cooling effect of water depths greater than 1000 m.

1986 ◽  
Vol 128 ◽  
pp. 103-121
Author(s):  
F Surlyk ◽  
S Piasecki ◽  
F Rolle

Active petroleum exploration in East Greenland is of fairly recent date and was preceded by a much longer history of scientific work and mineral exploration. The discovery in 1948 of lead-zinc mineralisation at Mestersvig resulted in the formation of Nordisk Mineselskab AIS in 1952. In the beginning of the seventies Nordisk Mineselskab initiated cooperation with the American oil company Atlantic Richfield (ARCO) in order to undertake petroleum exploration in Jameson Land. The Jameson Land basin contains a very thick Upper Palaeozoic - Mesozoic sedimentary sequence. Important potential source rocks are Lower Permian lacustrine mudstone, Upper Permian black marine mudstone, Middle Triassic dark marine limestone, uppermost Triassic black marginal marine mudstone, Lower Jurassic black mudstone and Upper Jurassic deep shelf black mudstone. Tbe Upper Permian mudstone, which is the most promising source rock, is immature to weakly mature along the western basin margin and is expected to be in the oil or gas-generating zone when deeply buried in the central part of the basin. Potential reservoir rocks include Upper Permian bank and mound limestones, uppermost Permian fan delta sandstones, Lower Triassic aeolian and braided river sandstones, and Lower, Middle and Upper Jurassic sandstones. The most important trap types are expected to be stratigraphic, such as Upper Permian limestone bodies, or combination stratigraphic-structural such as uppermost Permian or Lower Triassic sandstones in Early Triassic tilted fault blocks. In the offshore areas additional play types are probably to be found in tilted Jurassic fault blocks containing thick Lower, Middle and Upper Jurassic sandstones and lowermost Cretaceous sandstones and conglomerates. The recognition of the potential of the Upper Permian in petroleum exploration in East Greenland has important implications for petroleum exploration on the Norwegian shelf.


2013 ◽  
Vol 53 (1) ◽  
pp. 97 ◽  
Author(s):  
Nadege Rollet ◽  
Chris Nicholson ◽  
Andrew Jones ◽  
Emmanuelle Grosjean ◽  
George Bernardel ◽  
...  

The 2013 Acreage Release Areas W13-19 and W13-20 in the offshore northern Perth Basin, Western Australia, cover more than 19,000 km2 in parts of the Houtman, Abrolhos, Zeewyck and Gascoyne sub-basins. The Release Areas are located adjacent to WA-481-P, the only active offshore exploration permit in the Perth Basin, granted to joint venture partners Murphy Australia Oil Pty Ltd, Kufpec Australia Pty Ltd and Samsung Oil and Gas Australia Pty Ltd in August 2012. Geoscience Australia recently undertook a regional prospectivity study in the area as part of the Australian Government’s Offshore Energy Security Program, which provides fresh insights into basin evolution and hydrocarbon prospectivity. A sequence stratigraphic framework, based on new biostratigraphic sampling and interpretation, and an updated tectonostratigraphic model, using multiple 1D burial history models for Permian to Cenozoic sequences, have been developed. New geochemical studies of key offshore wells demonstrate that the oil-prone source interval of the Lopingian–Lower Triassic Hovea Member extends regionally offshore into the Abrolhos Sub-basin and potentially as far as the Houtman Sub-basin. This is supported by fluid inclusion data that provide evidence for palaeo-oil columns within Permian reservoirs in wells from the Abrolhos Sub-basin. Oil trapped in fluid inclusions in Houtman-1 can be linked to Jurassic source rocks, suggesting that multiple petroleum systems are effective in the Release Areas. The presence of active petroleum systems is also supported by the results of a recent marine survey. Potential seepage sites on the seafloor over reactivated faults correlate with hydroacoustic flares, pockmarks and dark colored viscous fluids that were observed over the areas. This may indicate an active modern-day petroleum system in the Houtman Sub-basin. Finally, a trap integrity analysis was undertaken to mitigate exploration risks associated with trap failure during Early Cretaceous breakup and provides a predictive approach to prospect assessment. These results provide strong support for the presence of active petroleum systems in the offshore northern Perth Basin and upgrade the prospectivity of the Release Areas.


1999 ◽  
Vol 39 (1) ◽  
pp. 364 ◽  
Author(s):  
S.A. Smith ◽  
P.R. Tingate ◽  
C.M. Griffths ◽  
J.N.F. Hull

The Roebuck Basin is a sparsely explored, frontier province located between the Carnarvon and Browse basins on Australia's North West Shelf. Mapping of the main structural and depositional elements of the basin has led to the identification of new features and elucidated the basin's tectonic history.The newly-identified Oobagooma High is a 25 km wide north-south oriented, elongate structure that separates the Oobagooma and Rowley sub-basins at the Palaeozoic level. This structure links with the Bedout High to form a major hinge zone that stretches across the entire basin.In the study area, three sub-divisions of the Fitzroy Movement are observed which have been termed Fitzroy Movement I, II and III, of Middle Triassic, Late Triassic and Early Jurassic ages. A previously unidentified breakup event linked to Fitzroy Movement III in the Early Jurassic is inferred from the stratal geometries in the basin.The region lacks a source rock equivalent to the Upper Jurassic Dingo Claystone of the contiguous Carnarvon Basin. However, Lower Triassic marine shale and deltaic sands are well developed in the Bedout Sub-basin and based on the results of forward stratigraphic modelling using SEDPAK™ software and sequence stratigraphic correlations these sediments, have high source potential over most of the untested Rowley Sub-basin. Possible Jurassic source rocks in the Roebuck Basin were deposited under fluvio-deltaic conditions during waning thermal sag. Thinly developed sapropel zones exist in the Bedout Sub-basin but potential exists for greater thicknesses in the Rowley Sub-basin. This potential is suggested by the seismic character, sedimentary architecture and sedimentary modelling of Lower Jurassic rocks in the basin. Preliminary thermal modelling indicates that source rocks would have generated significant hydrocarbons from Middle Jurassic to the present. Timing of generation is favourable for trap formation.


2016 ◽  
Vol 56 (1) ◽  
pp. 483 ◽  
Author(s):  
Nadege Rollet ◽  
Emmanuelle Grosjean ◽  
Dianne Edwards ◽  
Tehani Palu ◽  
Steve Abbott ◽  
...  

The Browse Basin hosts large gas accumulations, some of which are being developed for conventional liquefied natural gas (LNG). Extensive appraisal drilling has been focused in the central Caswell Sub-basin at Ichthys and Prelude, and along the extended Brecknock-Scott Reef Trend; whereas elsewhere the basin remains underexplored. To provide a better understanding of regional hydrocarbon prospectivity, the sequence stratigraphy of the Cretaceous succession and structural framework were analysed to determine the spatial relationship of reservoir and seal pairs, and those areas of enhanced source rock development. The sequence stratigraphic interpretation is based upon a common North West Shelf stratigraphic framework that has been developed in conjunction with industry, and aligned with the international time scale. Sixty key wells and 2D and 3D seismic data have been interpreted to produce palaeogeographic maps and depositional models for the Cretaceous succession. Geochemical analyses have characterised the molecular and stable isotopic signatures of fluids and correlated them with potential source rocks. The resultant petroleum systems model provides a more detailed understanding of source rock maturity, organic richness and hydrocarbon-generation potential in the basin. The model reveals that many accumulations have a complex charge history, with the mixing of hydrocarbon fluids from multiple Mesozoic source rocks, including the Lower–Middle Jurassic J10–J20 supersequences (Plover Formation), Upper Jurassic–Lowermost Cretaceous J30–K10 supersequences (Vulcan Formation), and Lower Cretaceous K20–K30 supersequences (Echuca Shoals Formation). Burial history and hydrocarbon expulsion models, applied to these Jurassic and Cretaceous supersequences, suggest that numerous petroleum systems are effective within the basin. For example, hydrocarbons are interpreted to have been generated from several source pods within the southern Caswell Sub-basin with migration continuing onto the Yampi Shelf, an area of renewed exploration interest.


2011 ◽  
Vol 356-360 ◽  
pp. 2929-2932 ◽  
Author(s):  
Yan Ran Huang ◽  
Zhi Huan Zhang ◽  
Ji Yong Liu

On Lower Yangtze region source rocks of Permian and the Lower Triassic activation energy distribution suggests that source rocks experienced some hydrocarbon generation reaction, generally high activation energy mainly because of high maturity, the weighted average activation energy has good positive correlation with maturity. The time of hydrocarbon generation in Huang Qiao area is short, and it’s speed is fast; the time in Ju Rong area is longer, characteristics is prone to early and multi-period; source rocks in Chao Hu region been uplifted to surface, the thermal evolution is lowest of all, and the time is longest. Source rocks secondary hydrocarbon generation exists in many area in Lower Yangtze region, the degree of hydrocarbon generation is mainly depend on sedimentary burial history.


Author(s):  
N.I. Samokhvalov ◽  
◽  
K.V. Kovalenko ◽  
N.A. Skibitskaya ◽  
◽  
...  
Keyword(s):  

2019 ◽  
Vol 56 (4) ◽  
pp. 365-396
Author(s):  
Debra Higley ◽  
Catherine Enomoto

Nine 1D burial history models were built across the Appalachian basin to reconstruct the burial, erosional, and thermal maturation histories of contained petroleum source rocks. Models were calibrated to measured downhole temperatures, and to vitrinite reflectance (% Ro) data for Devonian through Pennsylvanian source rocks. The highest levels of thermal maturity in petroleum source rocks are within and proximal to the Rome trough in the deep basin, which are also within the confluence of increased structural complexity and associated faulting, overpressured Devonian shales, and thick intervals of salt in the underlying Silurian Salina Group. Models incorporate minor erosion from 260 to 140 million years ago (Ma) that allows for extended burial and heating of underlying strata. Two modeled times of increased erosion, from 140 to 90 Ma and 23 to 5.3 Ma, are followed by lesser erosion from 5.3 Ma to Present. Absent strata are mainly Permian shales and sandstone; thickness of these removed layers increased from about 6200 ft (1890 m) west of the Rome trough to as much as 9650 ft (2940 m) within the trough. The onset of oil generation based on 0.6% Ro ranges from 387 to 306 Ma for the Utica Shale, and 359 to 282 Ma for Middle Devonian to basal Mississippian shales. The ~1.2% Ro onset of wet gas generation ranges from 360 to 281 Ma in the Utica Shale, and 298 to 150 Ma for Devonian to lowermost Mississippian shales.


Author(s):  
Lars Stemmerik ◽  
Gregers Dam ◽  
Nanna Noe-Nygaard ◽  
Stefan Piasecki ◽  
Finn Surlyk

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemmerik, L., Dam, G., Noe-Nygaard, N., Piasecki, S., & Surlyk, F. (1998). Sequence stratigraphy of source and reservoir rocks in the Upper Permian and Jurassic of Jameson Land, East Greenland. Geology of Greenland Survey Bulletin, 180, 43-54. https://doi.org/10.34194/ggub.v180.5085 _______________ Approximately half of the hydrocarbons discovered in the North Atlantic petroleum provinces are found in sandstones of latest Triassic – Jurassic age with the Middle Jurassic Brent Group, and its correlatives, being the economically most important reservoir unit accounting for approximately 25% of the reserves. Hydrocarbons in these reservoirs are generated mainly from the Upper Jurassic Kimmeridge Clay and its correlatives with additional contributions from Middle Jurassic coal, Lower Jurassic marine shales and Devonian lacustrine shales. Equivalents to these deeply buried rocks crop out in the well-exposed sedimentary basins of East Greenland where more detailed studies are possible and these basins are frequently used for analogue studies (Fig. 1). Investigations in East Greenland have documented four major organic-rich shale units which are potential source rocks for hydrocarbons. They include marine shales of the Upper Permian Ravnefjeld Formation (Fig. 2), the Middle Jurassic Sortehat Formation and the Upper Jurassic Hareelv Formation (Fig. 4) and lacustrine shales of the uppermost Triassic – lowermost Jurassic Kap Stewart Group (Fig. 3; Surlyk et al. 1986b; Dam & Christiansen 1990; Christiansen et al. 1992, 1993; Dam et al. 1995; Krabbe 1996). Potential reservoir units include Upper Permian shallow marine platform and build-up carbonates of the Wegener Halvø Formation, lacustrine sandstones of the Rhaetian–Sinemurian Kap Stewart Group and marine sandstones of the Pliensbachian–Aalenian Neill Klinter Group, the Upper Bajocian – Callovian Pelion Formation and Upper Oxfordian – Kimmeridgian Hareelv Formation (Figs 2–4; Christiansen et al. 1992). The Jurassic sandstones of Jameson Land are well known as excellent analogues for hydrocarbon reservoirs in the northern North Sea and offshore mid-Norway. The best documented examples are the turbidite sands of the Hareelv Formation as an analogue for the Magnus oil field and the many Paleogene oil and gas fields, the shallow marine Pelion Formation as an analogue for the Brent Group in the Viking Graben and correlative Garn Group of the Norwegian Shelf, the Neill Klinter Group as an analogue for the Tilje, Ror, Ile and Not Formations and the Kap Stewart Group for the Åre Formation (Surlyk 1987, 1991; Dam & Surlyk 1995; Dam et al. 1995; Surlyk & Noe-Nygaard 1995; Engkilde & Surlyk in press). The presence of pre-Late Jurassic source rocks in Jameson Land suggests the presence of correlative source rocks offshore mid-Norway where the Upper Jurassic source rocks are not sufficiently deeply buried to generate hydrocarbons. The Upper Permian Ravnefjeld Formation in particular provides a useful source rock analogue both there and in more distant areas such as the Barents Sea. The present paper is a summary of a research project supported by the Danish Ministry of Environment and Energy (Piasecki et al. 1994). The aim of the project is to improve our understanding of the distribution of source and reservoir rocks by the application of sequence stratigraphy to the basin analysis. We have focused on the Upper Permian and uppermost Triassic– Jurassic successions where the presence of source and reservoir rocks are well documented from previous studies. Field work during the summer of 1993 included biostratigraphic, sedimentological and sequence stratigraphic studies of selected time slices and was supplemented by drilling of 11 shallow cores (Piasecki et al. 1994). The results so far arising from this work are collected in Piasecki et al. (1997), and the present summary highlights the petroleum-related implications.


2021 ◽  
Vol 64 (3) ◽  
pp. 470-493 ◽  
Author(s):  
Jianping Chen ◽  
Xulong Wang ◽  
Jianfa Chen ◽  
Yunyan Ni ◽  
Baoli Xiang ◽  
...  

2021 ◽  
pp. 1-17
Author(s):  
Behnam Shafiei Bafti ◽  
István Dunkl ◽  
Saeed Madanipour

Abstract The recently developed fluorite (U–Th)/He thermochronology (FHe) technique was applied to date fluorite mineralization and elucidate the exhumation history of the Mazandaran Fluorspar Mining District (MFMD) located in the east Central Alborz Mountains, Iran. A total of 32 fluorite single-crystal samples from four Middle Triassic carbonate-hosted fluorite deposits were dated. The presented FHe ages range between c. 85 Ma (age of fluorite mineralization) and c. 20 Ma (erosional cooling during the exhumation of the Alborz Mountains). The Late Cretaceous FHe ages (i.e. 84.5 ± 3.6, 78.8 ± 4.4 and 72.3 ± 3.5 Ma) are interpreted as the age of mineralization and confirm an epigenetic origin for ore mineralization in the MFMD, likely a result of prolonged hydrothermal circulation of basinal brines through potential source rocks. Most FHe ages scatter around the Eocene Epoch (55.4 ± 3.9 to 33.1 ± 1.7 Ma), recording an important cooling event after heating by regional magmatism in an extensional tectonic regime. Cooling of the heated fluorites, as a result of thermal relaxation in response to geothermal gradient re-equilibration after the end of magmatism, or exhumation cooling during extensional tectonics characterized by lower amount of erosion are most probably the causes of the recorded Eocene FHe cooling ages. Oligocene–Miocene FHe ages (i.e. 27.6 ± 1.4 to 19.5 ± 1.1 Ma) are related to the accelerated uplift of the whole Alborz Mountains, possibly as a result of the initial collision between the Afro-Arabian and Eurasian plates further to the south.


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