Geochemical characterisation, volumetric assessment and shale-oil/gas potential of the Middle Jurassic–Lower Cretaceous source rocks of NE Arabian Plate

ABSTRACT The Middle Jurassic–Lower Cretaceous strata of the NE Arabian Plate contain several prolific source rocks providing the charge to some of the largest world-class petroleum systems. They are located within the Zagros Fold Belt and Mesopotamian Foreland Basins covering the northern, central and southeastern parts of Iraq, Kuwait and western and southwestern Iran, particularly the Lurestan and Khuzestan provinces. These source rocks include the Bajocian–Bathonian Sargelu, the Callovian–Lower Kimmeridgian Naokelekan and the Upper Tithonian–Lower Berriasian Chia Gara formations of Iraq and their chronostratigraphic equivalents in Kuwait and Iran. They have charged the main Cretaceous and Cenozoic (Tertiary) reservoirs throughout Iraq, Kuwait and Iran with more than 250 billion barrels of proven recoverable hydrocarbons. These formations represent the transgressive system tracts of sequences deposited within deep basinal settings and anoxic environments. They are dominated by black shales and bituminous marly limestones, with high total organic carbon (TOC) contents (ranging from 1–18 wt%), and by marine Type IIS kerogen. Their Rock-Eval S2 yields may reach up to 60 mg HC/g Rock, particularly along the depocentre of the Mesopotamian Foreland Basin. The immature hydrogen index (HI) values might have been up to 700 mg HC/g TOC, whereas the present-day observed values vary depending on the location within the basin and the present-day maturity. The Source-Potential Index (SPI; i.e. mass of hydrocarbons in tons, which could be generated from an area of 1 sq m in case of 100% transformation ratio) averages around 2–3, but can even reach up to 14–16 along the basins’ centres. The Sargelu and the overlying Naokelekan-basinal Najmah formations (and their equivalents) could represent the best potential shale-gas/shale-oil plays in Iraq, Kuwait and Iran, due to their organic richness, favourable maturity and the presence of regional upper and lower seals. The estimated oil-in-place for the potential Sargelu shale-oil play in Iraq only is around 1,300–2,500 billion barrel oil-equivalent (BBOE) and in Kuwait is about 7–150 BBOE.

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Geochemical Characterization and Volumetric Assessment of the Prolific Mesozoic Source Rocks of the Northeastern Arabian Plate

Fourth Arabian Plate Geology Workshop ◽

10.3997/2214-4609.20142780 ◽

2012 ◽

Author(s):

A. Aqrawi ◽

B. Badics

Keyword(s):

Source Rocks ◽

Arabian Plate ◽

Geochemical Characterization ◽

Volumetric Assessment

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Significance of angular unconformities between Cretaceous and Tertiary strata in the northwestern segment of the Zagros fold–thrust belt, Kurdistan Region, NE Iraq

Geological Magazine ◽

10.1017/s0016756811000471 ◽

2011 ◽

Vol 148 (5-6) ◽

pp. 925-939 ◽

Cited By ~ 27

Author(s):

KAMAL H. KARIM ◽

HEMIN KOYI ◽

MUSHIR M. BAZIANY ◽

KHALED HESSAMI

Keyword(s):

Lower Cretaceous ◽

Foreland Basin ◽

Geological Mapping ◽

Passive Margin ◽

Arabian Plate ◽

Thrust Belt ◽

Kurdistan Region ◽

Stratigraphic Position ◽

First Time ◽

Red Bed

AbstractIn this study, two angular unconformities are found and analysed for the first time in the Mesozoic–Cenozoic succession in the northwestern segment of the Zagros fold–thrust belt (ZFTB) in the Kurdistan Region. The first unconformity exists between Lower Cretaceous and Paleocene–Eocene rocks and the second between the Campanian Shiranish Formation and the Maastrichtian Tanjero Formation. Each of these unconformities is found in two different localities in the Zagros Imbricate Zone (i.e. the highly deformed zone immediately SW of the Zagros Suture) of the ZFTB of the Kurdistan Region near the border with Iran. The study uses recent geological mapping, structural and stratigraphic analyses in addition to using previous biozonation of the stratigraphic units that bound the two unconformities. The first unconformity was initiated with obduction of the ophiolite and Lower Cretaceous radiolarite onto the passive margin of the Arabian plate. This unconformity formed during an early phase of the Zagros orogeny, which is associated with the developing of a foreland basin, and resulted in the folding of the radiolarites and their uplift to form high-relief land. The erosion of this high-relief land resulted in the formation of the Paleocene–Eocene Red Bed Series and their deposition on the folded radiolarite. The timing of the deformation that caused this unconformity is hard to determine; however, its stratigraphic position may suggest that it possibly is related to post-Cenomanian movements. The second unconformity is between the tilted Campanian Shiranish Formation (hemipelagite) and Tanjero Formation (500 m of conglomerate in the more proximal area). These unconformities indicate that deformation and uplift of the sedimentary units was variable during ophiolite obduction in this part of the ZFTB. We argue that deformation, ophiolite obduction and collision are likely to have varied in space and time along the c. 2000 km long ZFTB.

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Arctic Alaska Basin, Hanna Trough, and Beaufortian Rifted Margin Composite Tectono-Sedimentary Elements

Geological Society London Memoirs ◽

10.1144/m57-2018-26 ◽

2021 ◽

pp. M57-2018-26

Author(s):

David W. Houseknecht

Keyword(s):

Lower Cretaceous ◽

Middle Jurassic ◽

Source Rocks ◽

The Arctic ◽

North Slope ◽

Growth Strata ◽

Middle Mississippian ◽

Arctic Alaska ◽

Sag Basin ◽

Rifted Margin

AbstractThe Arctic Alaska region includes three composite tectono-sedimentary elements (CTSEs): the (1) Arctic Alaska Basin (AAB), (2) Hanna Trough (HT), and (3) Beaufortian Rifted Margin (BRM) CTSEs. These CTSEs comprise Mississippian to Lower Cretaceous (Neocomian) strata beneath much of the Alaska North Slope, the Chukchi Sea and westernmost North Slope, and Beaufort Sea, respectively. These sedimentary successions rest on Devonian and older sedimentary and metasedimentary rocks, considered economic basement, and are overlain by Cretaceous to Cenozoic syn- and post-tectonic strata deposited in the foreland of the Chukotka and Brooks Range orogens and in the Amerasia Basin. (1) The Mississippian-Neocomian AAB CTSE includes two TSEs: (a) The Ellesmerian Platform TSE comprises mainly shelf strata of Mississippian to Middle Jurassic age and includes a relatively undeformed domain in the north and a fold-and-thrust domain in the south. (b) The Beaufortian Rift Shoulder TSE includes Middle Jurassic to Neocomian deposits related to rift-shoulder uplift. (2) The HT CTSE includes four TSEs: (a) The Ellesmerian Syn-Rift TSE comprises Late Devonian(?) to Middle Mississippian growth strata deposited in grabens and half grabens during intracontinental rifting. (b) The Ellesmerian-Beaufortian Sag-Basin TSE comprises Middle Mississippian to Upper Triassic strata deposited in a sag basin following cessation of rifting. (c) The Beaufortian Syn-Rift TSE comprises Jurassic to Neocomian graben-fill deposits related to rifting in the Amerasia and North Chukchi Basins. (d) The Beaufortian Rift-Shoulder TSE comprises Jurassic to Neocomian strata related to rifting and deposited outside rift basins. (3) The BRM CTSE includes two TSEs: (a) The Beaufortian Syn-Rift TSE comprises Middle Jurassic to Neocomian syn-rift strata deposited on attenuated continental crust associated with opening of the Amerasia Basin. (b) The Ellesmerian Platform TSE comprises mainly shelf strata of Mississippian to Middle Jurassic age that lie beneath Beaufortian syn-rift strata.The AAB, HT, and BRM CTSEs contain oil-prone source rocks in Triassic, Jurassic, and Cretaceous strata and proven reservoir rocks spanning Mississippian to Lower Cretaceous strata. A structurally high-standing area in the northern AAB CTSE, northern HT CTSE, and southernmost BRM CTSE lies in the oil window whereas all other areas lie in the gas window. Known hydrocarbon accumulations in the three CTSEs total more than 30 billion barrels of oil equivalent and yet-to-find estimates suggest a similar volume remains to be discovered.

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Evaluation of the nature, origin and potentiality of the subsurface Middle Jurassic and Lower Cretaceous source rocks in Melleiha G-1x well, North Western Desert, Egypt

Egyptian Journal of Petroleum ◽

10.1016/j.ejpe.2015.07.012 ◽

2015 ◽

Vol 24 (3) ◽

pp. 317-323 ◽

Cited By ~ 6

Author(s):

Mohamed M. El Nady

Keyword(s):

Lower Cretaceous ◽

Middle Jurassic ◽

Source Rocks ◽

Western Desert ◽

North Western

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Petroleum Systems in the Paris Sedimentary Basin, Europe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.931 ◽

2012 ◽

Vol 616-618 ◽

pp. 931-934

Author(s):

Hai Yan Hu ◽

Song Lu ◽

Hang Zhou Xiao

Keyword(s):

Lower Cretaceous ◽

Middle Jurassic ◽

Middle Triassic ◽

Sedimentary Basin ◽

Source Rocks ◽

Paris Basin ◽

Upper Carboniferous ◽

Petroleum Systems ◽

Northern Half ◽

The City

The Paris Basin encompasses most part of the northern half of France and is roughly circular in shape, centered around the city of Paris. Three known source rocks intervals are recognized in the basin. Main reservoirs in the basin were composed of the Triassic sandstones, Middle Jurassic (Dogger) limestones and Lower Cretaceous (Neocomian) sandstones. Interbedded continental red shales provide seals for the Middle Triassic deltaic sandstones and parallel dolomitic reservoirs. There were the nine hydrocarbon plays in the basin. Three known petroleum systems are recognized in the basin. They are Upper Carboniferous - Triassic, Middle Lias - Triassic and Upper Lias - Dogger petroleum systems.

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Coal rank and burial history of Cretaceous – Tertiary strata in the Grande Cache and Hinton areas, Alberta, Canada: implications for fossil fuel exploration

Canadian Journal of Earth Sciences ◽

10.1139/e96-071 ◽

1996 ◽

Vol 33 (6) ◽

pp. 938-957 ◽

Cited By ~ 11

Author(s):

W. Kalkreuth ◽

M. McMechan

Keyword(s):

Lower Cretaceous ◽

Upper Cretaceous ◽

Foreland Basin ◽

Source Rocks ◽

Thermal Modelling ◽

Coal Rank ◽

Thermal Maturity ◽

Burial History ◽

Near Surface ◽

Coal Measures

The present study discusses coal rank and burial histories for Cretaceous–Tertiary coal measures and thermal maturity of associated source rocks. Coal rank ranges from subbituminous to semianthracite. Coalification maps for selected coal zones indicate a broad coalification maximum east of the deformed belt. In the Pocahontas, Brûlé, and Hinton areas, rank levels appear to be elevated locally due to geothermal anomalies. Thermal modelling indicates that the westward decrease of coal rank in Lower Cretaceous strata is related to a westward decrease in the duration of burial beneath Maastrichtian–Eocene foreland-basin deposits. Upper Cretaceous – Tertiary strata were subjected to relatively low geothermal gradients (< 20 °C/km), whereas Lower Cretaceous strata were exposed to much higher gradients (up to 46 °C/km). Tectonic loading in the foothills had only a minor impact on coalification. At Obed Marsh (Alberta Syncline) thermal modelling suggests that deformation in the thrust belt continued for at least a few million years beyond the 60 Ma age recently suggested by fission-track analysis to indicate the end of Laramide deformation. Petroleum source rock intervals of the study area are currently at various stages of thermal maturity (oil generation window to dry gas zone). Coal seams in the Upper Cretaceous – Tertiary coal measures at and near surface have rank levels suitable for combustion, whereas seams in the Lower Cretaceous coal measures are high-quality metallurgical coals. East of the deformed belt the coal measures occur at depths that at the present time are uneconomic for production.

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First evidence of the early cretaceous oceanic anoxic events (MBE and OAE1a) in the southern Tethyan margin (NE-Tunisia): biostratigraphy and shale resource system

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01126-0 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1559-1575

Author(s):

Rachida Talbi ◽

Ahlem Amri ◽

Abdelhamid Boujemaa ◽

Hakim Gabtni ◽

Reginal Spiller ◽

...

Keyword(s):

Black Shale ◽

Saturation Index ◽

Black Shales ◽

Source Rocks ◽

Type I ◽

Hydrocarbon Generation ◽

Shale Oil ◽

Hydrocarbon Generation Potential ◽

Anoxic Events ◽

Rock Eval

AbstractThe Jebel Oust region (north-eastern Tunisia) recorded two levels of marine black shale in the Lower Cretaceous marly series. Geodynamic evolution, biostratigraphic and Rock–Eval analysies allow classifying those black shales as unconventional shale oil resource systems that were deposited during two oceanic anoxic events: the Middel Barremian Event "MBE" and the Early Aptian Event "OAE1a". Paleogeographic evolution highlights two transgressive–regressive cycles: the first one is Valanginian-Early Barremian, and the second is Late Barremian–Early Aptian. Each black shale deposit occurs at the end of the transgression that coincides with the highest sea level. During the Barreman–Aptian interval, sedimentation was controlled by extensional faults in a system of tilted fault blocks which were reactivated several times. Kerogen is of type I, II origin in black shales and of type III origin in marls. Tmax values indicate "oil window" stage. Average transformation ratio is around 67% and 82%, respectively, in the Lower Aptian and Middel Barremian source rock related to the relatively high thermal maturity degree due to the deep burial of the later. Estimated initial hydrocarbon generation potential is moderate to high. Oil saturation index records an "oil crossover" indicating expelled and migrated hydrocarbons from the organic-rich to the organic-poor facies. The petroleum system of the two mature source rocks with a high hydrocarbon generation potential enclose all elements characterizing a "shale oil hybrid system with a combination of juxtaposed organic-rich and organic-lean facies associated with open fractures".

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Sequence stratigraphy of source and reservoir rocks in the Upper Permian and Jurassic of Jameson Land, East Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v180.5085 ◽

1998 ◽

pp. 43-54 ◽

Cited By ~ 3

Author(s):

Lars Stemmerik ◽

Gregers Dam ◽

Nanna Noe-Nygaard ◽

Stefan Piasecki ◽

Finn Surlyk

Keyword(s):

Sequence Stratigraphy ◽

Middle Jurassic ◽

Sedimentary Basins ◽

Upper Jurassic ◽

Oil Field ◽

Source Rocks ◽

Upper Permian ◽

Shallow Marine ◽

East Greenland ◽

Reservoir Rocks

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.

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