THE GULF OF CARPENTARIA—A NEW BASIN AND NEW EXPLORATION TARGETS

1993 ◽  
Vol 33 (1) ◽  
pp. 297
Author(s):  
V. L. Passmore ◽  
P. E. Williamson ◽  
T. U Mating ◽  
A.R.G. Gray
Keyword(s):  
Shallow Water ◽  
Sedimentary Rocks ◽  
High Amplitude ◽  
Source Rocks ◽  
Petroleum Potential ◽  
Basin Floor ◽  
International Boundary ◽  
Fault Structures ◽  
The One ◽  
Sag Basin

The sparsely explored Gulf of Carpentaria is a shallow water frontier area of stacked basins. The petroleum potential was not tested by the one offshore well drilled in the Gulf in 1984.Recent re-interpretation of offshore seismic in Queensland waters delineated the Bamaga Basin, a new infrabasin below the Carpentaria Basin. This new basin is a northerly trending asymmetrical sag basin that continues north of the international boundary. The Bamaga Basin, containing up to 1.8 seconds of gently folded and faulted sediments, is untested and offers a new exploration objective. Apparent high velocities make the age of the basin uncertain, but Paleozoic reservoir and source rocks, similar to sedimentary rocks in nearby basins, are inferred, although analogue basins are not readily identifiable.Bamaga Basin source rock burial is sufficient to generate hydrocarbons and could source reservoirs in the Bamaga and Carpentaria Basins via migration along faults. Possible direct hydrocarbon indicators increase support for the presence of hydrocarbons in the Gulf.Structural and stratigraphic plays in the Carpentaria Basin that provide new exploration targets include: basal sandstones onlapping areas of higher relief or filling basin floor depressions, sandstone layers within the Wallumbilla Formation draping highs and possible carbonate zones appearing as high amplitude chaotic reflectors. Within the Bamaga Basin, horst, fault structures and anticlinal features are potential structural plays, and termination of units against the main unconformity are possible stratigraphic play targets.

scholarly journals Geochemistry and geochronology of the Paleozoic sedimentary rocks in the Shar Khutul area, Central Mongolia

2018 ◽  
pp. 4-21
Author(s):  
Erdenechimeg D ◽  
Oyunchimeg T ◽  
Otgonbaatar D ◽  
Jitka Míková ◽  
Tomurchudur Ch ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sedimentary Rocks ◽  
Thin Layers ◽  
Detrital Zircons ◽  
Source Rocks ◽  
Coarse Grained ◽  
Al2o3 Content ◽  
Oceanic Plate ◽  
Stratigraphic Unit ◽  
Middle Carboniferous

The study area is located in the central part of Tsetserleg terrane in the southwestern margin of the Khangai-Khentey orogenic system. The paper presents new data on geochemistry and geochronology of sedimentary rocks from the Shar Khutul area, where the Tsetserleg terrane consists of Silurian-Devonian oceanic plate stratigraphic unit and Carboniferous shallow water sediment. The Upper Silurian to Middle Devonian Erdenetsogt Formation (S3-D2er), which is an oceanic plate stratigraphic unit, is mainly composed of siliceous siltstone, volcanites, tuffs, quartzite, and cherts. The shallow water sediments are divided into Upper Devonian to Lower Carboniferous Tsetserleg Formation (D3-C1cc) and Lower–Middle Carboniferous Dzargalant Formation (C1-2dz). The Tsetserleg Formation (D3-C1cc) consists of only sedimentary rocks such as bluish-grey sandstones and siltstones, and Lower–Middle Carboniferous Dzargalant Formation (C1-2dz) is principally composed of medium- to coarse-grained, brown-greenish grey sandstones with thin-layers of dark siltstones and gravelites. The SiO2 content of the Shar Khutul area sandstones ranges from 63.85 to 67.95 wt.% and the average content of TiO2 is 0.72 wt.% and Al2O3 content is 14.38 wt.%. The Chemical Index of Alteration (CIA) value ranges from 48.71 to 56.94 and the range of Index of compositional variations (ICV) is from 0.98 to 1.24. Moreover, the samples studied show that most of the sandstones are generally immature and were derived from weakly weathered source rocks. The ratios of Eu/Eu* (0.83), La/Sc (3.81), La/Co (5.30), and Cr/Th (13.81) indicate that the derivation of the Shar Khutul area sandstones from felsic rock sources and confirm the signatures of a felsic igneous provenance and suggest an active continental margin tectonic setting of the source area. The clastic zircons from the medium grained sandstone (Erdenetsogt formation) yield ages between 2.5 Ga and 236 Ma and the detrital zircons exhibit four peak ages at 1.7-2.5 Ga (n = 13), 455-499 Ma (n = 6), 337-382 Ma (n = 13) and 236–250 Ma (n = 5).

Deep fluids and their role in hydrocarbon migration and oil deposit formation exemplified by supercritical СO2

2021 ◽  
pp. 1-11
Author(s):  
Sara LIFSHITS
Keyword(s):  
Supercritical Fluid ◽  
Oil And Gas ◽  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Source Rocks ◽  
Reservoir Properties ◽  
Hydrocarbon Migration ◽  
Geological Processes ◽  
Before And After ◽  
Oil Source

ABSTRACT Hydrocarbon migration mechanism into a reservoir is one of the most controversial in oil and gas geology. The research aimed to study the effect of supercritical carbon dioxide (СО2) on the permeability of sedimentary rocks (carbonates, argillite, oil shale), which was assessed by the yield of chloroform extracts and gas permeability (carbonate, argillite) before and after the treatment of rocks with supercritical СО2. An increase in the permeability of dense potentially oil-source rocks has been noted, which is explained by the dissolution of carbonates to bicarbonates due to the high chemical activity of supercritical СО2 and water dissolved in it. Similarly, in geological processes, the introduction of deep supercritical fluid into sedimentary rocks can increase the permeability and, possibly, the porosity of rocks, which will facilitate the primary migration of hydrocarbons and improve the reservoir properties of the rocks. The considered mechanism of hydrocarbon migration in the flow of deep supercritical fluid makes it possible to revise the time and duration of the formation of gas–oil deposits decreasingly, as well as to explain features in the formation of various sources of hydrocarbons and observed inflow of oil into operating and exhausted wells.

scholarly journals Paleoenvironment of the Lower–Middle Cambrian Evaporite Series in the Tarim Basin and Its Impact on the Organic Matter Enrichment of Shallow Water Source Rocks

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 659
Author(s):  
Mingyang Wei ◽  
Zhidong Bao ◽  
Axel Munnecke ◽  
Wei Liu ◽  
G. William M. Harrison ◽  
...  
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Tarim Basin ◽  
Water Environment ◽  
Water Source ◽  
Major Elements ◽  
Source Rocks ◽  
Middle Cambrian ◽  
Sedimentary Environments ◽  
The Impact

Just as in deep-water sedimentary environments, productive source rocks can be developed in an evaporitic platform, where claystones are interbedded with evaporites and carbonates. However, the impact of the paleoenvironment on the organic matter enrichment of shallow water source rocks in an evaporite series has not been well explored. In this study, two wells in the central uplift of the Tarim Basin were systematically sampled and analyzed for a basic geochemical study, including major elements, trace elements, and total organic carbon (TOC), to understand the relationship between TOC and the paleoenvironmental parameters, such as paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity. The results show that the Lower–Middle Cambrian mainly developed in a fluctuating salinity, weak anoxic to anoxic, continuous dry and hot, and proper shallow water environment. The interfingering section of evaporites, carbonates, and claystones of the Awatag Fm. have higher paleoproductivity and higher enrichment of organic matter. Paleosalinity, redox, paleoclimate, paleo-seawater depth, and paleoproductivity jointly control the organic matter enrichment of shallow water source rocks in the evaporite series. The degree of enrichment of organic matter in shallow water source rocks first increases and then decreases with the increase in paleosalinity. All the samples with high content of organic matter come from the shallower environment of the Awatag Fm.

The Yenisei-Khatanga Composite Tectono-Sedimentary Element, Northern Siberia

2021 ◽  
pp. M57-2021-15
Author(s):  
E. V. Deev ◽  
G. G. Shemin ◽  
V. A. Vernikovsky ◽  
O. I. Bostrikov ◽  
P. A. Glazyrin ◽  
...  
Keyword(s):  
Siberian Craton ◽  
Middle Triassic ◽  
Foreland Basin ◽  
Early Carboniferous ◽  
Source Rocks ◽  
Total Thickness ◽  
Petroleum Potential ◽  
Early Paleocene ◽  
Middle Carboniferous ◽  
Severnaya Zemlya

AbstractThe Yenisei-Khatanga Composite Tectono-Sedimentary Element (YKh CTSE) is located between the Siberian Craton and the Taimyr-Severnaya Zemlya fold-and-thrust belt. The total thickness of the Mesoproterozoic-Cenozoic sediments of YKh CTSE reaches 20 to 25 km. They are divided into four tectono-sedimentary elements (TSE): (i) Mesoproterozoic-early Carboniferous Siberian Craton continental margin, (ii) middle Carboniferous-Middle Triassic syn-orogenic Taimyr foreland basin, (iii) late Permian-Early Triassic syn-rift, and (iv) Triassic-Early Paleocene post-rift. The last one is the most important in terms of its petroleum potential and is the most drilled part of the CTSE. Its thickness accounts for half of the total thickness of YKh CTSE. The margins of the post-rift TSE and the inner system of inversion swells and adjacent troughs and depressions were shaped by three tectonic events: (i) middle Carboniferous-Middle Triassic Taimyr orogeny, (ii) Late Jurassic-Early Cretaceous Verkhoyansk orogeny, (iii) Late Cenozoic uplift. These processes led to more intense migration of hydrocarbons, the trap formation and their infill with hydrocarbons. Triassic, Jurassic, and Lower Cretaceous source rocks are mostly gas-prone, and among 20 discovered fields in Jurassic and Cretaceous plays, 17 are gas or mixed-type fields.

A Balanced Approximation of the One-Layer Shallow-Water Equations on a Sphere

2009 ◽  
Vol 66 (6) ◽  
pp. 1735-1748 ◽  
Author(s):  
W. T. M. Verkley
Keyword(s):  
Shallow Water ◽  
Potential Vorticity ◽  
Shallow Water Equations ◽  
Rossby Waves ◽  
Coriolis Parameter ◽  
Beta Plane ◽  
Propagating Waves ◽  
Barotropic Vorticity Equation ◽  
Barotropic Vorticity ◽  
The One

Abstract A global version of the equivalent barotropic vorticity equation is derived for the one-layer shallow-water equations on a sphere. The equation has the same form as the corresponding beta plane version, but with one important difference: the stretching (Cressman) term in the expression of the potential vorticity retains its full dependence on f 2, where f is the Coriolis parameter. As a check of the resulting system, the dynamics of linear Rossby waves are considered. It is shown that these waves are rather accurate approximations of the westward-propagating waves of the second class of the original shallow-water equations. It is also concluded that for Rossby waves with short meridional wavelengths the factor f 2 in the stretching term can be replaced by the constant value f02, where f0 is the Coriolis parameter at ±45° latitude.

An overview of the Ionian zone source rocks and petroleum potential of NW Greece (Ioannina concession block)

First Break ◽  
2014 ◽  
Vol 32 (12) ◽  
Author(s):  
Henry David ◽  
Constantinos Tzimeas ◽  
Paschalia Kiomourtzi ◽  
Panagiotis Konstantopoulos ◽  
George Panagopoulos ◽  
...  
Keyword(s):  
Source Rocks ◽  
Petroleum Potential

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.

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