A geochemical investigation into the resource potential of the Lawn Hill Platform, northern Australia

2020 ◽  
Vol 60 (2) ◽  
pp. 722
Author(s):  
Amber J. M. Jarrett ◽  
Adam E. H. Bailey ◽  
Christopher J. Boreham ◽  
Tehani Palu ◽  
Lisa Hall ◽  
...  
Keyword(s):  
Organic Geochemistry ◽  
Source Rocks ◽  
Geochemical Data ◽  
Northern Australia ◽  
Hydraulic Stimulation ◽  
Petroleum Potential ◽  
North West ◽  
North Eastern ◽  
Resource Exploration ◽  
Geochemical Investigation

The Lawn Hill Platform (LHP) is a sedimentary province in north-eastern Northern Territory and north-western Queensland that hosts a significant Paleoproterozoic–Mesoproterozoic sequence, often referred to as 'the ‘Isa Superbasin’, and includes the overlying South Nicholson Group. Shale gas resources and base-metals mineralisation are known in north-west Queensland, but the larger basin is underexplored. The Australian Government’s Exploring for the Future (EFTF) 2016−2020 program aims to boost resource exploration in northern Australia. New precompetitive geochemical data obtained in this program includes source rock geochemistry, kerogen kinetics, bitumen reflectance, biomarker and δ13C n-alkanes for understanding the petroleum potential, organic geochemistry of source rocks and fluids, stratigraphic correlations and mineralogy to determine the brittleness of shales. All data and derived reports are accessible on the EFTF portal (www.eftf.ga.gov.au), providing a central location for informed decision making. The results in this study demonstrate fair to excellent source rocks in multiple supersequences that are brittle and favourable to hydraulic stimulation. A comparison to the greater McArthur Basin demonstrates, that although there are many similarities in bulk geochemistry, LHP mudstones are largely heterogeneous, reflecting local variations that may be inherited from variations in contributing biomass, microbial reworking, depositional environment, sediment input and paleoredox conditions.

Population genetics of two tropical sharks, Carcharhinus tilstoni and C. sorrah, in Northern Australia

1989 ◽  
Vol 40 (5) ◽  
pp. 541 ◽  
Author(s):  
S Lavery ◽  
JB Shaklee
Keyword(s):  
Eastern Coast ◽  
Population Subdivision ◽  
Starch Gel Electrophoresis ◽  
Northern Australia ◽  
Tissue Samples ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Starch Gel ◽  
Sufficient Variation

The genetic structure of the Australian populations of Carcharhinus tilstoni and C. sorrah was investigated by starch gel electrophoresis. Tissue samples were taken from 1580 sharks from throughout the fishery, which extends from the North-West Shelf (off Western Australia) to the north-eastern coast of Queensland. From a total of 47 enzyme loci screened in each species, 13 proved to be polymorphic (P0.99) for at least one species, with only 5 loci for each species showing sufficient variation (P0.95) to be of use in the analysis of population structure. Mean heterozygosity values were relatively low: 0.037 for C. tilstoni and 0.035 for C. sorrah. A low level of population subdivision was found within each species, with FST values of 0.0094 for C. tilstoni and 0.0076 for C. sorrah. There was insufficient evidence to suggest that there is more than one population of either species of shark in Australian waters.

HYDROCARBON GENERATION AND EXPULSION FROM EARLY CRETACEOUS SOURCE ROCKS IN THE BROWSE BASIN, NORTH WEST SHELF, AUSTRALIA: A SMALL ANGLE NEUTRON SCATTERING STUDY

2004 ◽  
Vol 44 (1) ◽  
pp. 151 ◽  
Author(s):  
A.P. Radlinski ◽  
J.M. Kennard ◽  
D.S. Edwards ◽  
A.L. Hinde ◽  
R. Davenport
Keyword(s):  
Neutron Scattering ◽  
Pore Size ◽  
Source Rock ◽  
Early Cretaceous ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Source Rocks ◽  
Geochemical Data ◽  
Hydrocarbon Generation ◽  
North West

Small Angle Neutron Scattering (SANS) analyses were carried out on 165 potential source rocks of Late Jurassic–Early Cretaceous age from nine wells in the Browse Basin (Adele–1, Argus–1, Brecknock South–1, Brewster–1A, Carbine–1, Crux–1, Dinichthys–1, Gorgonichthys–1 and Titanichthys–1). Samples from Brewster–1A and Dinichthys–1 were also analysed using the Ultra Small Angle Neutron Scattering (USANS) technique.The SANS/USANS data detect the presence of generated bitumen and mobile hydrocarbons in pores and are pore-size specific. As the pore-size range in mudstones extends from about 0.001–30 μm, the presence of bitumen in the small pores detected by SANS indicates the depth of onset of hydrocarbon generation, whereas the presence of bitumen and mobile hydrocarbons in the largest pores detected by USANS indicates a significant saturation and the onset of expulsion.Although geochemical data imply the existence of a potential gas and oil source rock in the Lower Cretaceous section (Echuca Shoals and Jamieson Formations), the SANS/USANS data indicate significant generation but little or no expulsion. This source limitation may explain poor exploration success for liquid hydrocarbons in the area. The SANS/USANS data provide evidence of intra- and inter-formational hydrocarbon migration or kerogen kinetics barriers. There is no evidence of an oil charge to the Berriasian Brewster Sandstone from the Echuca Shoals Formation, although some gas charge in Brewster–1A is possible. This novel microstructural technique can be used to independently calibrate and refine source rock generation/expulsion scenarios derived from geochemistry modelling.

AN ALTERNATIVE VIEW ON INDO-AUSTRALIAN COALS AS A SOURCE OF PETROLEUM

1994 ◽  
Vol 34 (1) ◽  
pp. 256 ◽  
Author(s):  
Barry Jay Katz
Keyword(s):  
Northern Hemisphere ◽  
Genetic Relationships ◽  
Primary Source ◽  
Source Rocks ◽  
Geochemical Data ◽  
Alternative View ◽  
Apparent Absence ◽  
Petroleum Potential ◽  
Marine Source ◽  
Oil Source

Numerous studies have argued that coals are the primary source for much of the petroleum in the Indo-Australian region. These studies have invoked this genetic relationship because of similarities in n-alkane distributions among coal extracts and oils and the apparent absence of conventional sources. Others have suggested that the ability of southern hemisphere coals to source oil is a result of differences in the nature of their precursors compared to their gas-prone northern hemisphere counterparts.Suggested genetic relationships are challenged through several independent approaches. Organic geochemical data reveal that these coals display characteristics similar to their northern hemisphere, gas-prone counterparts. They appear capable of generating large volumes of heavy hydrocarbons but are incapable of expelling them within the oil-window. Other data reveal that many of the region's proposed oil-source rock correlations are internally inconsistent. And finally, data are becoming available which indicate that conventional lacustrine or marginal marine source rocks are present.This alternative view of the petroleum potential of coals is significant in that it alters exploration concepts and mass-balance calculations of reserves.

THE PETROLEUM POTENTIAL OF THE GUNNED AH BASIN AND OVERLYING SURAT BASIN SEQUENCE, NEW SOUTH WALES

1988 ◽  
Vol 28 (1) ◽  
pp. 218 ◽  
Author(s):  
D.S. Hamilton ◽  
C.B. Newton ◽  
M. Smyth ◽  
T.D. Gilbert ◽  
N. Russell ◽  
...  
Keyword(s):  
Vitrinite Reflectance ◽  
Source Rocks ◽  
Lower Permian ◽  
Petroleum Potential ◽  
Shallow Marine ◽  
North West ◽  
South Wales ◽  
Oil Generation ◽  
Origin Of Oil ◽  
Auto Fluorescence

The Permo-Triassic Gunnedah Basin has good potential for the discovery of commercial petroleum. Gas shows have been reported from the Porcupine-Watermark, Black Jack and Digby Formations, and from the basal sandstone of the Purlawaugh Formation in the overlying Surat Basin sequence. Gas flowed on drill stem test from the Porcupine-Watermark Formation in the Wilga Park No. 1 discovery well although the find was sub-commercial. An oil show was observed in Lower Permian volcanics, and oil staining has been observed in the Pilliga Sandstone in several wells. The origin of oil staining in the Pilliga Sandstone is unknown, however, and may have been the result of diesel contamination during drilling operations.Structural style within the basin sequence is characterised by north-south and north-north-west/south- south-east trending anticlines which formed in response to periodic compressive and left lateral strike-slip movements along the main Hunter Mooki Thrust Fault. These anticlines are attractive exploration targets.Westerly-derived quartz-rich sandstones occur at several stratigraphic levels within the Black Jack Formation and within the upper Digby Formation. Sandstones of the western bed-load fluvial system (lower Black Jack Formation) are most prospective with thick sections (up to 8 m) giving permeabilities from several hundred to several thousand millidarcies. Marine reworked easterly-derived sandstones up to 12 m thick in the Black Jack and Watermark Formations have minor reservoir potential with permeabilities in the order of tens of millidarcies. All potential reservoirs within the sequence are considered to be adequately sealed. Regionally extensive shaly units deposited either by marine incursion or lacustrine inundation overlie most reservoir horizons; remaining reservoirs are capped by intraformational shales.Organic petrology and geochemistry indicate the best potential source rocks within the Gunnedah Basin are floodplain, lacustrine and shallow marine facies of the Purlawaugh, Napperby, Watermark, Maules Creek and Goonbri Formations. The shallow marine Arkarula Sandstone Member within the Black Jack Formation also has significant potential for oil generation. Vitrinite reflectance, liptinite auto-fluorescence and TAI values indicate Lower Permian sediments are marginally mature to mature for oil generation. Combining the data on source quality and quantity with thermal maturity, the Permian sediments - in particular the Watermark Formation - have the best potential for generating oil.

scholarly journals Geophysical and petroleum geological activities in the Nuussuaq – Svartenhuk Halvø area 1994: promising results for an onshore exploration potential

1995 ◽  
Vol 165 ◽  
pp. 32-41
Author(s):  
F.G Christiansen ◽  
C Marcussen ◽  
J.A Chalmers
Keyword(s):  
Field Work ◽  
Source Rocks ◽  
Geochemical Data ◽  
Successful Completion ◽  
West Greenland ◽  
North West ◽  
Important Study ◽  
A Minor

After the successful completion of the 1993 field work and drilling programme in the Marraat area on western Nuussuaq (Fig. 1), including a subsequent logging and geophysical programme (see Christiansen et al., 1994a, b; Dam & Christiansen, 1994), a new picture of onshore ex­ploration opportunities has started to develop. Previously the onshore basins were only considered to have a minor exploration potential, if any at all. However, the Disko-Nuussuaq-Svartenhuk Halvo region has been an important study area because many of the key parameters (sedimentological, stratigraphical and organic geochemical data from the excellent outcrops) may be obtained for predicting the distribution of reservoir and source rocks in the neighbouring major offshore basins in North-West and West Greenland (Christiansen et al., 1992, I994c).

VITRINITE REFLECTANCE SUPPRESSION IN COAL DUE TO A MARINE TRANSGRESSION: CASE STUDY OF THE ORGANIC GEOCHEMISTRY OF THE GRETA SEAM, SYDNEY BASIN

1994 ◽  
Vol 34 (1) ◽  
pp. 241 ◽  
Author(s):  
S. C. George ◽  
J. W. Smith ◽  
D. R. Jardine
Keyword(s):  
Organic Geochemistry ◽  
Vitrinite Reflectance ◽  
Bimodal Distribution ◽  
Atomic Ratio ◽  
Petroleum Exploration ◽  
North West ◽  
The North ◽  
Geochemical Parameters ◽  
Marine Influence ◽  
Geochemical Investigation

Vitrinite reflectance suppression in marine sequences is a major problem facing some petroleum exploration companies. It leads to considerable difficulties in determining thermal maturity in exploration provinces like the North West Shelf of Australia. The Permian Greta seam, northern Sydney Basin, is a classical example of a marine-influenced coal which displays a vitrinite reflectance suppression of 0.25 per cent R0. It is an ideal candidate for detailed organic geochemical investigation of this problem. The amount and composition of extractable hydrocarbons in the coal appear to be only partially related to vitrinite reflectance, so it is unlikely that suppression is directly caused by the adsorption of hydrocarbons into the vitrinite matrix. Vitrinite reflectance is inversely proportional to the H/C atomic ratio, suggesting that the observed suppression is caused by the more perhydrous nature of vitrinite in marine-influenced coals. At the molecular level the marine influence can clearly be distinguished in the top metre of the seam by depleted amounts of n-alkanes with a lower carbon preference index and a slightly bimodal distribution, a lower pristane/phytane ratio and considerably more hopanes and diasteranes. In addition to the peat-derived humic compounds prevalent throughout the seam, these geochemical parameters indicate bacterial re-working of the newly deposited peat and a direct contribution of marinederived lipids at the top of the seam. Fluctuations in n-alkane and isoprenoid distributions and abundances elsewhere in the seam indicate that the depositional environment changed periodically.

THE GEOLOGY AND PETROLEUM POTENTIAL OF THE WESTERN ARAFURA SEA

1990 ◽  
Vol 30 (1) ◽  
pp. 91 ◽  
Author(s):  
Jeanette M. McLennan ◽  
John S. Rasidi ◽  
Richard L. Holmes ◽  
Greg C. Smith
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Petroleum Potential ◽  
Northern Margin ◽  
The North ◽  
Australian Plate ◽  
North Eastern ◽  
Arafura Sea ◽  
Good Potential ◽  
Reservoir Potential

The northern Bonaparte Basin and the Arafura-Money Shoal Basins lie along Australia's offshore northern margin and offer significantly different exploration prospects resulting from their differing tectonic and burial histories. The Arafura Basin is dominated by a deep, faulted and folded, NW-SE orientated Palaeozoic graben overlain by the relatively flat-lying Jurassic-Tertiary Money Shoal Basin. The north-eastern Bonaparte Basin is dominated by the deep NE-SW orientated Malita Graben with mainly Jurassic to Recent basin-fill.A variety of potential structural and stratigraphic traps occur in the region especially associated with the grabens. They include tilted or horst fault blocks and large compressional, drape and rollover anticlines. Some inversion and possibly interference anticlines result from late Cenozoic collision between the Australian plate and Timor and the Banda Arc.In the Arafura-Money Shoal Basins, good petroleum source rocks occur in the Cambrian, Carboniferous and Jurassic-Cretaceous sequences although maturation is biassed towards early graben development. Jurassic-Neocomian sandstones have the best reservoir potential, Carboniferous clastics offer moderate prospects, and Palaeozoic carbonates require porosity enhancement.The Malita Graben probably contains good potential Jurassic source rocks which commenced generation in the Late Cretaceous. Deep burial in the graben has decreased porosity of the Jurassic-Neocomian sandstones significantly but potential reservoirs may occur on the shallower flanks.The region is sparsely explored and no commercial discoveries exist. However, oil and gas indications are common in a variety of Palaeozoic and Mesozoic sequences and structural settings. These provide sufficient encouragement for a new round of exploration.

THE STRUCTURAL DEVELOPMENT AND PETROLEUM POTENTIAL OF THE ROEBUCK BASIN

1999 ◽  
Vol 39 (1) ◽  
pp. 364 ◽  
Author(s):  
S.A. Smith ◽  
P.R. Tingate ◽  
C.M. Griffths ◽  
J.N.F. Hull
Keyword(s):  
Lower Triassic ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Source Rocks ◽  
Late Triassic ◽  
Structural Development ◽  
Petroleum Potential ◽  
North West ◽  
Sedimentary Architecture

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.

scholarly journals Source rock characterization and oil grouping in the NW Java, Central Java and NE Java Basins, Indonesia

2021 ◽  
Vol 47 (2) ◽  
pp. 48-66
Author(s):  
Ragil Pratiwi
Keyword(s):  
Organic Geochemistry ◽  
Hierarchical Cluster ◽  
Source Rocks ◽  
Geochemical Data ◽  
Crude Oils ◽  
Central Java ◽  
Agglomerative Hierarchical Cluster Analysis ◽  
Marine Source ◽  
Group 5 ◽  
Rock Characterization

This study reveals the detailed organic geochemistry from crude oils (acquired from wells and seepages) and rock extracts from NW Java and NE Java Basin that have been gathered and compiled from previous publications. The interpretation was conducted from geochemical data value and plot, GC-MS fingerprints, and agglomerative-hierarchical cluster analysis using the Euclidean algorithm. Various source rocks from those basins were deposited under fluvio-lacustrine to the marine environment. Six groups of crude oils are also distinguished. Groups 1, 2, and 6 are oils from deltaic source rocks, Groups 3 and 4 are oils from marine source rocks, and Group 5 is from lacustrine and/or fluvio-lacustrine source rocks. Groups 1, 2, and 6 could be distinguished from the pristane/phytane (Pr/Ph) ratio and C29 sterane composition, while Groups 3 and 4 differ from the distribution of C27 sterane. The schematic depositional environment of source rocks is also generated from this study and suggests that Group 5 is deposited during early syn-rift non-marine settings, while the remaining groups are deposited in the deltaic (Group 1,2 and 6) and marine settings (Groups 3 and 4). The main differences between those groups are including the distributions of C27-C28-C29 steranes.

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