Application of Vitrinite Reflectance to Interpret Gas Content, Maximum Depth of Burial, and Paleogeothermal Gradient of Coal Beds in Dunkard Basin: ABSTRACT

The offshore Sydney Basin is unique frontier acreage because it is adjacent to Australia's largest gas and petroleum market on the east coast of New South Wales. Although the onshore Sydney Basin has been tested by more than 100 petroleum exploration wells, no wells have been drilled offshore.New South Wales Permit NSW/P10 has an area of 9419 km2 and extends over the offshore northern and central Sydney Basin which contains Upper Carboniferous to Middle Triassic lithiclastic and siliciclastic sedimentary rocks and volcanics. Maximum depth to magnetic basement in NSW/P10 is greater that 9 km in the southern Macquarie Syncline and south of the New England Fold Belt at the continental margin. Recent seismic reprocessing and aeromagnetic surveying have focused the exploration effort on northern NSW/P10 where thick (greater than 1600 m) Upper Permian section containing source and reservoir facies is predicted. Other areas in the permit are less prospective because of widespread intrasedimentary magnetic bodies or the absence by erosion of Upper Permian and Triassic section.The Sydney Basin is an exhumed basin that reached its maximum depth of burial in the Early Cretaceous prior to basinwide uplift of 1.5-3.5 km during the Tasman Sea rifting. The magnitude and timing of the exhumation can be demonstrated with fluid inclusion, magnetisation, fission track and vitrinite reflectance data. The presence of commercial quantities of oil or gas in Upper Permian reservoirs depends on trap integrity having been maintained during the epeirogeny, or the re-migration of hydrocarbon into new traps.

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RELATIONS BETWEEN DEPTH OF BURIAL, VITRINITE REFLECTANCE AND GEOTHERMAL GRADIENT: VITRINITE REFLECTANCE DATA FOR THE LONE STAR BERTHA ROGERS BOREHOLE

Journal of Petroleum Geology ◽

10.1111/j.1747-5457.1999.tb00471.x ◽

1999 ◽

Vol 22 (2) ◽

pp. 233-234 ◽

Cited By ~ 1

Author(s):

R. P. Suggate

Keyword(s):

Vitrinite Reflectance ◽

Geothermal Gradient ◽

Depth Of Burial ◽

Reflectance Data

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Controls on Gas Domains and Production Behaviour in A High-Rank CSG Reservoir: Insights from Molecular and Isotopic Chemistry of Co-Produced Waters and Gases from the Bowen Basin, Australia

Geosciences ◽

10.3390/geosciences10020074 ◽

2020 ◽

Vol 10 (2) ◽

pp. 74 ◽

Cited By ~ 1

Author(s):

Stephanie K. Hamilton ◽

Suzanne D. Golding ◽

Joan S. Esterle ◽

Kim A. Baublys ◽

Brycson B. Ruyobya

Keyword(s):

Carbon Isotope ◽

Vitrinite Reflectance ◽

Isotope Analysis ◽

Co2 Reduction ◽

Production Performance ◽

High Rank ◽

Gas Content ◽

Coal Seams ◽

Gas Generation ◽

Geographic Variations

This paper uses hydrochemical and multi-isotope analysis to investigate geological controls on coal seam gas (CSG) saturation domains and gas well production performance in a high-rank (vitrinite reflectance (Rv) > 1.1) CSG field in the north-western Bowen Basin, Australia. New hydrochemical and stable isotope data were combined with existing geochemical datasets to refine hypotheses on the distribution and origins of CSG in two highly compartmentalized Permian coal seams. Stable isotopic results suggest that geographic variations in gas content, saturation and production reflect the extent of secondary microbial gas generation and retention as a function of hydrodynamics. δ13C and δ2H data support a gas mixing hypothesis with δ13C-CH4 increasing from secondary biogenic values to thermogenic values at depth (δ13C −62.2‰ to −46.3‰), whereas correlated methane and carbon dioxide carbon isotope compositions, Δ13C(CO2–CH4) values and δ13CDIC/alkalinity trends are largely consistent with microbial CO2 reduction. In addition, below 200 m, the majority of δ13C-CO2 values are positive (δ13C: −1.2‰ to 7.1‰) and δ13CDIC shows an erratic increase with depth for both seams that is characteristic of evolution via microbial activity. The progression of carbon isotope values along the CO2 reduction fractionation line suggests progressive depletion of the CO2 reservoir with increasing depth. Faults clearly segment coal seams into areas having significantly different production, with results of geochemical analysis suggesting that pooling of biogenic gas and waters and enhanced methanogenesis occur north of a faulted hinge zone.

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RELATIONS BETWEEN DEPTH OF BURIAL, VITRINITE REFLECTANCE AND GEOTHERMAL GRADIENT: THE LONE STAR BERTHA ROGERS BOREHOLE, ANADARKO BASIN, OKLAHOMA, USA — THE WORLD'S DEEPEST EXPLORATION BOREHOLE

Journal of Petroleum Geology ◽

10.1111/j.1747-5457.1999.tb00470.x ◽

1999 ◽

Vol 22 (2) ◽

pp. 229-231

Author(s):

G. M. Friedman

Keyword(s):

Vitrinite Reflectance ◽

Geothermal Gradient ◽

Anadarko Basin ◽

Depth Of Burial

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BEST BOUNDS ON DENSITY AND DEPTH FROM GRAVITY DATA

Geophysics ◽

10.1190/1.1440454 ◽

1974 ◽

Vol 39 (5) ◽

pp. 644-649 ◽

Cited By ~ 71

Author(s):

Robert L. Parker

Keyword(s):

Lower Bound ◽

General Theory ◽

Upper Bound ◽

Incomplete Data ◽

Extreme Values ◽

Gravity Data ◽

Maximum Depth ◽

Analytic Methods ◽

Depth Of Burial

Gravity data cannot usually be inverted to yield unique structures from incomplete data; however, there is a smallest density compatible with the data or, if the density is known, a deepest depth of burial. A general theory is derived which gives the greatest lower bound on density or the least upper bound on depth. These bounds are discovered by consideration of a class of “ideal” bodies which achieve the extreme values of depth or density. The theory is illustrated with several examples which are solved by analytic methods. New maximum depth rules derived by this theory are, unlike some earlier rules of this type, optimal for the data they treat.

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Geochemical investigation of hydrocarbon generation potential of coal from Raniganj Basin, India

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01281-4 ◽

2021 ◽

Vol 11 (10) ◽

pp. 3627-3636

Author(s):

D. S. Panwar ◽

Ram Chandra Chaurasia ◽

V. K. Saxena ◽

A. K. Singh ◽

Akanksha

Keyword(s):

Gas Content ◽

Coal Bed ◽

Hydrocarbon Generation ◽

Type Iii ◽

Coal Beds ◽

Petrographic Examination ◽

Raniganj Coalfield ◽

Geochemical Investigation ◽

A Minor ◽

Van Krevelen Diagram

AbstractMethane content in a coal seam is a necessary parameter for evaluating coal bed gas, and it poses an environmental risk to underground coal mining activities. Keeping in pace with comprehensive studies of coal bed gas, 12 coal samples were selected from the Sitarampur block of Raniganj Coalfield for analysis. The Petrographic examination illustrated that significant values of reactive macerals present in samples demonstrate that organic matter is dominated by the prominent source of aromatic hydrocarbons with a minor proportion of aliphatic hydrocarbon, which falls in the region of (Type III) kerogen, confirms the suitability for the potential of hydrocarbon generation. “A” factor (aliphatic/aromatic bands) and “C” factor (carbonyl/carboxyl bands) value concluded that the sample has the lowest aromaticity and the highest hydrocarbon-generating potential, which was also validated by the Van Krevelen diagram. The Van Krevelen diagram plots between the H/C and O/C ratio indicate that coal samples lie in the type III kerogen, and bituminous coal (gas prone zone) is present in the block, which is confirmed by the cross-plot between desorbed and total gas (cc/g). The in situ gas content values are high enough to produce methane from coal beds. The overall study concludes that the Sitarampur block from Raniganj Coalfield is suitable for hydrocarbon generation and extraction.

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THE WALLOON COAL MEASURES—THE NEXT COAL SEAM GASTARGET?

The APPEA Journal ◽

10.1071/aj99006 ◽

2000 ◽

Vol 40 (1) ◽

pp. 86

Author(s):

S.G. Scott ◽

P. Crosdale

Keyword(s):

Coal Seam ◽

Vitrinite Reflectance ◽

Petroleum Exploration ◽

Gas Content ◽

Coal Seam Gas ◽

Gas Industry ◽

Permian Coal ◽

Petroleum Wells ◽

The Individual ◽

Coal Measures

The Queensland coal seam gas industry has grown over the last 12 years. During this time the vast majority of exploration wells have targeted the Late Permian coal measures in the Bowen and Galilee Basins. These formations have been the major target because they contain coals with a vitrinite reflectance ranging above 0.7%. This range has always been seen as the main period for methane generation.As well as containing vast quantities of Permian coal, Queensland also has vast quantities of Middle Jurassic coals within its Mesozoic Basins. These coals have received little-to-no exploration for their coal seam gas potential as they have always been interpreted as being immature for gas generation.Over 550 petroleum exploration wells drilled in the Mesozoic Surat Basin of eastern Queensland were reviewed to determine the coal volume of the intersected Walloon Coal Measures. A significant number have intersected large volumes of sub-bituminous to high volatile bituminous coals, in seams ranging up to 11.7 m in thickness. While the individual seams are not laterally persistent, the coal packages can be traced over hundreds of kilometres of the eastern Surat Basin.While only one well has tested the gas content, gas quality and saturation of the Walloon Coal Measures, numerous water bores have reported gas flows from the zone, and petroleum wells intersecting the formation have recorded high mud gas readings during drilling.The relatively shallow depth of the unit over much of the basin, the thickness of the coal packages, the proximity to major gas trunk pipelines and markets make the Walloon Coal Measures an ideal target for the next generation of coal seam gas explorers.

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