PALAEOGEOGRAPHY OF THE AUSTRALIAN PERMIAN IN RELATION TO OIL SEARCH

1966 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
R. C. SPRIGG
Keyword(s):  
Continental Shelf ◽  
Nutrient Status ◽  
Hinge Line ◽  
Open Sea ◽  
Antarctic Convergence ◽  
Antarctic Waters ◽  
Eastern Australia ◽  
Petroleum Generation ◽  
Gondwana Land ◽  
Coal Measures

Aspects of Permian glaciomarine sedimentation in Australia in relation to petroleum generation are treated in the light of the "Gondwana-land" hypothesis and recent studies in palaeolatitudinal distribution of Tertiary oilfields. The Permian segment of the Gondwana (U. Dev. to Trias.) succession is characterised by Glossopteris-Gangamopteris flora, glacial. glaciomarine and glaciofluvial sediments, coal measures and cyclothems.Evolution of the Hunter-Bowen Geosyncline of eastern Australia was accompanied by major volcanic activity along an arc-like archipelago. Sedimentation in this longitudinal ortho-geosynclinal belt linked acrosn the continent via shallow infra-basins and intra-cratonic basins to a series of graben-troughs (Perth, Carnarvon, Fitzroy and Bonaparte) developing about the western margin of Neo-Australia. These latter elongate and generally extremely deep "basins" were early manifestations of, and incipient riftings related to, the embryonic Indian Ocean.The Permian (south) palaeomagnetic pole was located approximately 30 degrees of are west of south from Melbourne, placing Australia in relatively high southern latitudes. Middle to Upper Tertiary oilfields of the Northern Hemisphere on the other hand have been indicated elsewhere to be products of tropical palaeolatitudes from which it has been implied that warm temperatures may be critical in oil formation.Recent investigations indicate that, acre for acre, Antarctic waters are potentially richer in organic life than any other. This is related primarily to abundance of nitrates and phosphates brought into sunlit (20 or more hours per day in summer) waters by upwelling currents. In consequence a high nutrient status of marine waters may be more important than palaeolatitudes in facilitating organic build-up in accumulating sediments. More research into contemporaneous sedimentation in relation to "Antarctic Convergence" in continental shelf settings is undoubtedly desirable.The great variety of Australian palaeo-environments of Permian age includes those of the open sea, continental shelf, hinge-line, barred embayment and alternating marine to fresh water basin. These offer a range of settings favourable to the entombment of organic matter under a variety of conditions presumed favourable to the formation of petroleum source-beds. Encouraging discoveries at Yardarino (W.A.), Gidgealpa (S.A.) and Cabawin (Qld.) justify accelerated exploration for commercial petroleum in the Australian Permian.

Conodont Biostratigraphy of Ordovician Deep-Water Turbiditic Sequences in Eastern Australia—A New Biozonal Scheme for the Open-Sea Realm

2021 ◽  
Vol 32 (3) ◽  
pp. 486-500
Author(s):  
Yong Yi Zhen ◽  
Ian G. Percival ◽  
Phil Gilmore ◽  
Jodie Rutledge ◽  
Liann Deyssing
Keyword(s):  
Deep Water ◽  
Conodont Biostratigraphy ◽  
Open Sea ◽  
Eastern Australia

Optimization of Coal Seam Connectivity via Multi-Seam Pinpoint Fracturing Operations in the Walloons Coal Measures, Surat Basin

2021 ◽  
Author(s):  
Vibhas J. Pandey ◽  
Sameer Ganpule ◽  
Steven Dewar
Keyword(s):  
Coal Seam ◽  
History Matching ◽  
Design Matrix ◽  
Coal Seams ◽  
Major Step ◽  
Well Completion ◽  
Eastern Australia ◽  
Treatment Designs ◽  
Coal Measures ◽  
Gas Bearing

Abstract The Walloons coal measures located in Surat Basin (eastern Australia) is a well-known coal seam gas play that has been under production for several years. The well completion in this play is primarily driven by coal permeability which varies from 1 Darcy or more in regions with significant natural fractures to less than 1md in areas with underdeveloped cleat networks. For an economic development of the latter, fracturing treatment designs that effectively stimulate numerous and often thin coals seams, and enhance inter-seam connectivity, are a clear choice. Fracture stimulation of Surat basin coals however has its own challenges given their unique geologic and geomechanical features that include (a) low net to gross ratio of ~0.1 in nearly 300 m (984.3 ft) of gross interval, (b) on average 60 seams per well ranging from 0.4 m to 3 m in thickness, (c) non-gas bearing and reactive interburden, and (d) stress regimes that vary as a function of depth. To address these challenges, low rate, low viscosity, and high proppant concentration coiled tubing (CT) conveyed pinpoint stimulation methods were introduced basin-wide after successful technology pilots in 2015 (Pandey and Flottmann 2015). This novel stimulation technique led to noticeable improvements in the well performance, but also highlighted the areas that could be improved – especially stage spacing and standoff, perforation strategy, and number of stages, all aimed at maximizing coal coverage during well stimulation. This paper summarizes the findings from a 6-well multi-stage stimulation pilot aimed at studying fracture geometries to improve standoff efficiency and maximizing coal connectivity amongst various coal seams of Walloons coal package. In the design matrix that targeted shallow (300 to 600 m) gas-bearing coal seams, the stimulation treatments varied in volume, injection rate, proppant concentration, fluid type, perforation spacing, and standoff between adjacent stages. Treatment designs were simulated using a field-data calibrated, log-based stress model. After necessary adjustments in the field, the treatments were pumped down the CT at injection rates ranging from 12 to 16 bbl/min (0.032 to 0.042 m3/s). Post-stimulation modeling and history-matching using numerical simulators showed the dependence of fracture growth not only on pumping parameters, but also on depth. Shallower stages showed a strong propensity of limited growth which was corroborated by additional field measurements and previous work in the field (Kirk-Burnnand et al. 2015). These and other such observations led to revision of early guidelines on standoff and was considered a major step that now enabled a cost-effective inclusion of additional coal seams in the stimulation program. The learnings from the pilot study were implemented on development wells and can potentially also serve as a template for similar pinpoint completions worldwide.

Active and passive dispersal of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) larvae on the Sydney shelf

2000 ◽  
Vol 51 (3) ◽  
pp. 229 ◽  
Author(s):  
Kimberley A. Smith
Keyword(s):  
Continental Shelf ◽  
Larval Stage ◽  
Shelf Break ◽  
Outer Shelf ◽  
Size Distributions ◽  
Passive Dispersal ◽  
Larval Size ◽  
Larval Behaviour ◽  
Eastern Australia ◽  
Spawning Periods

Distributions of small and large larvae of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) were examined along a shore-normal transect across the Sydney continental shelf, south-eastern Australia during January and April 1994. Both species were abundant, and 3016 individuals of C. affinis and 3184 individuals of G. greyi were taken. Distributions of small and large C. affinis reflected hydrographic variability and suggested passive dispersal. Previous observations of high year-class variability for this species may therefore reflect oceanographic variability during the larval stage. In contrast, the distributions of G. greyi only partially reflected hydrography and appeared to be influenced by larval behaviour at both sizes. Size distributions during each month indicated protracted spawning periods for both species. Spawning by C. affinis may have occurred over the inner shelf although the location was unclear because of the complexity of nearshore currents. Spawning by G. greyi probably occurred over the outer shelf. An increasing influence of larval behaviour with larval size on the distribution of G. greyi restricted larger individuals to the shelf break; this may have been a response to higher productivity in this region.

The Flatback Turtle, Chelonia depressa, in Queensland: Post-Nesting Migration and Feeling Ground Distribution

1983 ◽  
Vol 10 (3) ◽  
pp. 557 ◽  
Author(s):  
CJ Limpus ◽  
CJ Parmenter ◽  
V Baker ◽  
A Fleay
Keyword(s):  
Continental Shelf ◽  
Great Barrier Reef ◽  
Adult Female ◽  
Barrier Reef ◽  
Inshore Water ◽  
Eastern Australia ◽  
North Eastern ◽  
Nesting Beaches ◽  
Feeding Grounds

Between 1968 and 1981, a total of 813 adult female flatback turtles were tagged while nesting on Queensland beaches. Eight have been recovered at a distance, 216-1300 km north of their respective nesting beaches, in waters between the mainland and the Great Barrier Reef. The species' principal feeding grounds seem to be in turbid, shallow inshore water off north-eastern Australia and in the Gulf of Carpentaria; there are no records beyond the continental shelf.

DISCOVERY AND DEVELOPMENT OF THE KOGAN NORTH AND TIPTON WEST COAL SEAM GAS (CSG) FIELDS, SURAT BASIN, SOUTHEAST QUEENSLAND

2006 ◽  
Vol 46 (1) ◽  
pp. 367 ◽  
Author(s):  
R.W. Day ◽  
R.F. Prefontaine ◽  
P.A.J. Bubendorfer ◽  
M.H. Oberhardt ◽  
B.J. Pinder ◽  
...  
Keyword(s):  
Coal Seam ◽  
Cultural Heritage ◽  
Gas Flow ◽  
Heritage Management ◽  
Management Systems ◽  
Coal Seam Gas ◽  
Cultural Heritage Management ◽  
Well Completion ◽  
Eastern Australia ◽  
Coal Measures

In 2001, Arrow Energy NL, a fledgling coal seam gas (CSG) explorer, drilled the first wells of a multi-well exploration program in two Authorities To Prospect (ATP) permits—ATPs 683P and 676P—that covered an area totalling 13,817 km2 of the Jurassic Walloon Coal Measures in the eastern Surat Basin. The objective was to discover significant CSG resources and, if successful, to commercialise to reserve status. Early exploration success in 2002 saw the discovery of the Kogan North and Tipton West CSG fields. This paper reviews the discovery and subsequent appraisal and development work that Arrow Energy has completed to establish production from these fields.By 2004, Arrow Energy had independently certified Probablereserves in the Kogan North field of 85 PJ, and Possible reserves of 157 PJ. Results from a five-well CSG pilot operation demonstrated the feasibility of commercial gas flow rates sufficiently to justify commercialising CSG from the Walloon Coal Measures in the Kogan North field. Under the terms of a staged development agreement, CS Energy Ltd—Queensland’s largest electricity generator—farmed into the Kogan North Project to earn a 50% interest in PL194 and an adjoining portion of ATP 676P by funding A$13.1 million of the project’s development and appraisalcosts. The funds provided by CS Energy covered the majority of the development costs required for Arrow’s Kogan North development project. The initial gas sales contract from Kogan North will supply sales gas of 4 PJ/a for 15 years to CS Energy from March 2006. Arrow Energy retains the remaining 50% interest and operates the project.With 25 PJ Probable, 90 PJ Probable and 1,980 PJ Possiblegas reserves certified independently, the Tipton West field could potentially be one of the largest onshore gas fields in eastern Australia. Final appraisal of the Tipton West field is currently underway with financial close on the development expected in late 2005. Beach Petroleum Ltd has entered into an agreement to fund the A$35 million required for upstream developmentto supply the initial 10 PJ/a sales gas from the field in 2007, in exchange for 40% interest in th Dalby block of ATP683P. Arrow Energy retains the remaining 60% interest and operates the project.Diligent environmental and land management systems are required with the development of any CSG field. For example, formation water produced from CSG activities needs to be managed effectively. To deal with this water Arrow Energy is developing and implementing several innovative strategies, including forced evaporation dams, water supply to local coal-washing plants and trialling desalination plants to provide drinking water for nearby towns, aquaculture and stock watering.Arrow Energy has also implemented a Cultural Heritage Management Plan within the development areas in cooperation with the local indigenous claimant groups, the Western Wakka Wakka and the Barunggam peoples. The plan was designed to minimise risk of any disturbance to indigenous artefacts and areas of significance during the exploration, construction and ongoing operations associated with the development of both gas fields.The discovery and future development of the Kogan North and Tipton West fields has been achieved by using an appropriate mix of geological evaluation, efficient drilling techniques, innovative well completion methods and successful marketing strategies, integrated with cooperative environmental and cultural heritage management systems.

THE SOUTH AUSTRALIAN CONTINENTAL SHELF AS A HABITAT FOR PETROLEUM

1964 ◽  
Vol 4 (1) ◽  
pp. 53
Author(s):  
Reg. C. Sprigg
Keyword(s):  
Continental Shelf ◽  
Lower Cretaceous ◽  
Structural Break ◽  
Continental Drift ◽  
South Australia ◽  
The South ◽  
The North ◽  
Preferred Habitat ◽  
Murray River ◽  
Petroleum Generation

The Continental Shelf off South Australia is predicted to be a preferred habitat of petroleum. Non-metamorphosed sediments which are known or presumed to extend onto this shelf include Permian, Cretaceous and Cainozoic sediments. A single presumed Permian trough lying seaward of, and sub-parallel to, the Coorong is interpreted (aeromagnetic data) to extend to possibly 4,000 feet. As part of the Permian fossil valley system of central-eastern South Australia is is predicted to be filled by shales and sands with limited marine facies, and by glacigene sediments. The north-south orientation of the trough would require a landmass to the south from which the Permian glaciers originated. Some form of continental drift may be required to satisfy this requirement.An east-west graben or geosyncline (Gambier-Otway Basin) choked with Cretaceous mudstones and sub-greywackes projects across the shelf in the extreme south-east. Landward dips at depth extending well out beneath the shelf, may suggest a southerly boundary to the basin consistent with a pre-existing landmass in this direction.Extensive erosion at the close of Lower Cretaceous times accords with major geological change at least in more southerly shelf areas. Marine sedimentary onlap and overlap become conspicuous elements, and the accumulation of oceanward thickening sedimentary deposits is more in keeping with outbuilding terrace development. A major structural break accordingly is indicated at the end of the Lower Cretaceous, at which time development of the modern continental shelf began.The Murray River had its principal outlets in the extreme south-east zone during mid-Cretaceous to early Tertiary times, but shifted to its present position during late Cainozoic at which time its sediments were swept across the developing shelf south of Kangaroo Island. Thick sedimentary developments in each of these areas provide promising environment for petroleum generation. These are areas of extensive coastal bitumen activity.Principal petroleum prospects are to be expected within the Middle Cretaceous to Tertiary developments, but older Cretaceous and Permian deposits are potentially prospective.

COALBED METHANE RESOURCES IN THE PERMIAN OF EASTERN AUSTRALIA AND THEIR TECTONIC SETTING

1993 ◽  
Vol 33 (1) ◽  
pp. 161 ◽  
Author(s):  
S. Miyazaki ◽  
R.J. Korsch
Keyword(s):  
Coalbed Methane ◽  
Tectonic Setting ◽  
Temporal Distribution ◽  
Low Permeability ◽  
Burial History ◽  
Coal Seams ◽  
Methane Drainage ◽  
Eastern Australia ◽  
Permian Coal ◽  
Coal Measures

The Bowen and Sydney Basins in eastern Australia contain vast coal resources which provide a source for coalbed methane. Through studies of the spatial and temporal distribution of the sedimentary packages, the structural geometry and tectonic setting of the sedimentary packages, and the maturation and burial history, the Australian Geological Survey Organisation (AGSO) is mapping the distribution and structural styles of the sources of methane, in particular, the Late Permian coal measures. AGSO's results from the Bowen Basin show at least two distinctly different structural styles of potential targets for coalbed methane drainage: on the Comet Ridge, the Permian coal measures are essentially subhorizontal and tectonically undisturbed, whereas in the western Taroom Trough, the coal measures are folded into a series of anticlines, each of which occurs above a thrust fault which in turn forms part of an imbricate thrust fan. Both of these styles occur at depths of less than 1000 m.Calculations by the Bureau of Resource Sciences (BRS) indicate that the inferred coalbed methane resources-in-place are 62 trillion cubic feet (1760 billion m3) for Australia, in which the Bowen and Sydney Basins are currently the only potential provinces of coalbed methane. The low permeability of the coal seams hinders attempts to utilise this vast amount of energy resources.Further exploration is necessary to delineate commercially feasible areas. This delineation is the only process that will be able to determine demonstrated coalbed methane resources.

Mapping horizons and fracture patterns in coal measures using magnetics for coalbed methane exploration in Queensland

2015 ◽  
Vol 55 (2) ◽  
pp. 443
Author(s):  
Irena Kivior ◽  
Stephen Markham ◽  
David Warner ◽  
Leslie Mellon
Keyword(s):  
Coalbed Methane ◽  
Magnetic Data ◽  
Mapping Technique ◽  
Stress Regime ◽  
Rock Fabric ◽  
Fracture Patterns ◽  
Eastern Australia ◽  
Hill Area ◽  
Well Data ◽  
Coal Measures

High resolution magnetic data has successfully been used to map the top and base of coal measures, related faults and fracture patterns across the Red Hill area in the northern Bowen Basin, eastern Australia. A horizon mapping technique, based on energy spectral analysis (ESA), was used to detect magnetic susceptibility contrasts that were laterally merged to form two magnetic interfaces, corresponding to the top of the Fair Hill Formation and base of the Goonyella Middle Seam in the Permian Moranbah coal measures. The depth estimates were made at stations on a regular mesh of 400 m x 400 m and at nine wells. The final detailed mapping of both horizons was constructed from spectral depth estimates on a regular mesh of 100 m x 100 m. Major faults, associated structures and fractures were mapped in 3D from the magnetic data by using automatic curve matching (ACM). This technique was applied to detect single magnetic anomalies produced by inter-sedimentary sources. These results were used to interpret magnetic lineaments in, above and below the coal measures to produce a rock fabric model. The results obtained from the interpretation of the magnetic data are consistent with structures mapped from existing seismic and well data. The mapped rock fabric was also confirmed by well results to be a fair representation of the open fracture set, which has an orientation that is consistent with the existing stress regime.

Spawning dynamics of the eastern gemfish (Rexea solandri) in relation to regional oceanography in south-eastern Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 611 ◽  
Author(s):  
Jeremy D. Prince ◽  
David A. Griffin
Keyword(s):  
Continental Shelf ◽  
Winter Season ◽  
Shelf Break ◽  
Sea Surface ◽  
Mode Water ◽  
Topographic Features ◽  
Warm Core ◽  
Eastern Australia ◽  
Northern Edge ◽  
Survival And Growth

Experienced fishers believe the winter aggregations of gemfish are influenced by the following: cold bottom currents from the south and east flowing up onto the shelf; the edge of warm-core eddies; and topographic features along the shelf break. These claims were tested through observations made at sea during industry surveys of the winter gemfish seasons 1996 –98, and the study of 250 m isotherm charts, sea surface temperature data, and historic catch data. The study generally confirmed the anecdotal information collected from the fishers. The first gemfish aggregations of the winter season often form on the southern edge of a warm-core eddy. Secondarily, aggregations tend to form around the northern edge of the warm-core eddy if it is interacting with the shelf break. Finally, gemfish aggregate around the point at which the main flow of the East Australian Current (EAC) detaches from the continental shelf. This timing and location apparently coincides with conditions conducive to the production of subsurface plumes of nutrient-rich deep Sub-Antarctic mode Water. These plumes lead to seasonal enhancement of phytoplankton growth along the edge of the continental shelf, which may offer the adaptive advantage of enhancing the survival and growth of larval gemfish.

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