EXPLORATION IN THE COOPER BASIN

1989 ◽  
Vol 29 (1) ◽  
pp. 366 ◽  
Author(s):  
R. Heath
Keyword(s):  
Oil And Gas ◽  
South Australia ◽  
Mature Stage ◽  
Small Contribution ◽  
Terrestrial Source ◽  
Seismic Acquisition ◽  
Proterozoic Basement ◽  
Gas Fields ◽  
Coal Measures ◽  
Cooper Basin

The Cooper Basin is located in the northeastern corner of South Australia and in the southwestern part of Queensland. The basin constitutes an intracratonic depocentre of Permo- Triassic age. The Cooper Basin succession unconformably overlies Proterozoic basement as well as sediments and metasediments of the Cambro- Ordovician age. An unconformity separates in turn the Cooper succession from the overlying Jurassic- Cretaceous Eromanga Basin sediments.The Permo- Triassic succession comprises several cycles of fluvial sandstones, fluvio- deltaic coal measures and lacustrine shales. The coal measures contain abundant humic kerogen, comprising mainly inertinite and vitrinite with a small contribution of exinite. All hydrocarbon accumulations within the Cooper Basin are believed to have originated from these terrestrial source rocks.Exploration of the basin commenced in 1959 and, after several dry holes, the first commercial discovery of gas was made at Gidgealpa in 1963. To date, some 97 gas fields and 10 oil fields, containing recoverable reserves of 5 trillion cubic feet of gas and 300 million barrels recoverable natural gas liquids and oil, have been discovered in the Cooper Basin. Production is obtained from all sand- bearing units within the Cooper stratigraphic succession.The emphasis of exploration in the Cooper Basin is largely directed towards the assessment of four- way dip closures and three- way dip closures with fault control, but several stratigraphic prospects have been drilled. Furthermore, in the development phase of some gas fields a stratigraphic component of the hydrocarbon trapping mechanism has been recognised.Improvements in seismic acquisition and processing, combined with innovative thinking by the explorers, have facilitated the development of untested structural/stratigraphic plays with large reserves potential. Exploration for the four- and three- way dip closure plays in the Cooper Basin is now at a mature stage. However, reserves objectives are expected to continue to be met, with the expectation of a continuing high success rate.Selected new plays are expected to be tested within a continuing active exploration program as exploration for oil and gas in the Cooper Basin refines the search for the subtle trap.

Comparative geological setting of conventional oil and gas fields and CSG resources in the Surat/Bowen Basin, Queensland

2009 ◽  
Vol 49 (2) ◽  
pp. 580
Author(s):  
Rob Willink
Keyword(s):  
Oil And Gas ◽  
Gas Content ◽  
Small Contribution ◽  
Coal Seams ◽  
Reservoir Properties ◽  
Oil And Gas Fields ◽  
The Difference ◽  
Permian Coal ◽  
Gas Fields ◽  
Coal Measures

The Surat/Bowen Basin has long been of interest to explorers in pursuit of gas and oil in conventional reservoirs. Some 500 BCF of gas and 32 million barrels of oil have been produced from sandstones of Permian, Triassic and Jurassic age. Geochemical evidence suggests that these hydrocarbons were sourced almost exclusively from Permian coal measures, though a small contribution from Triassic coals cannot be discounted. Primary interest in these basins today, however, resides in the exploration for, and commercialisation of, methane trapped in coal seams within the Permian and Jurassic successions. Total industry declared proven, probable and possible (3P) coal seam gas (CSG) reserves exceed 30 TCF, of which some 8 TCF are attributed to reserves in Permian coal seams, and 22 TCF in Jurassic coal seams. With particular reference to a representative regional seismic traverse through the basin, this presentation will explain why known conventional and CSG fields in these basins are located where they are from a regional structural and stratigraphic perspective. The difference between the reservoir properties of coals and sandstones, and between the Permian and Jurassic coals will be discussed in terms of their maceral composition, gas content, adsorption capacity and thermal maturity. In addition, the location of known sweetspots within CSG fairways will be revealed. The presentation will conclude with some speculative comments on what the future holds for both conventional and CSG exploration in these basins and will show that Origin Energy, in particular through its investment with Conoco Phillips in Australian Pacific LNG (APLNG), is well placed to participate in that future.

Old rocks, new tricks: a reinvigorated Cooper Basin offers growth opportunity

2019 ◽  
Vol 59 (2) ◽  
pp. 928
Author(s):  
Bill Ovenden
Keyword(s):  
Oil And Gas ◽  
Low Cost ◽  
New Technology ◽  
South Australia ◽  
Production Costs ◽  
Imaging Data ◽  
Oil And Gas Development ◽  
North East ◽  
Risk Appetite ◽  
Cooper Basin

The Cooper Basin spans north-east South Australia and south-west Queensland and is Australia’s largest integrated onshore oil and gas development. Santos and Delhi first discovered commercial gas in 1963. First oil was discovered in 1970. Since then, the Cooper Basin has become a strategically important processing and transportation hub for produced gas and liquids. Continuous investment in new technology, the use of existing infrastructure and, recently, an unrelenting drive to lower drilling and production costs has delivered a low-cost, high-margin producer for east coast domestic and liquefied natural gas (LNG) export markets. This improved operating performance has, in turn, offered Santos the opportunity to reassess ‘our backyard’. The Cooper Basin boasts many growth options, remaining and emerging. Seismic advances are providing improved imaging. Data management, the use of play-based exploration studies, innovative geoscience thinking and renewed investment risk appetite are playing key roles in the development of discovered resources and the exploration of new and emerging plays. Targeted wildcat exploration and appraisal programs, supported by low-cost operations, offer the potential to unlock significant remaining oil and gas resources. The Cooper Basin is poised for another stage of growth. This tangible potential emphasises the critical future role the basin is likely to continue to play as an onshore Australian hydrocarbon supply hub.

THE NATURAL CONVERSION OF OIL TO GAS IN SEDIMENTS IN THE COOPER BASIN

1971 ◽  
Vol 11 (1) ◽  
pp. 121
Author(s):  
J.D. Brooks ◽  
W.R. Hesp ◽  
D. Rigby
Keyword(s):  
Oil And Gas ◽  
South Australia ◽  
High Rank ◽  
Average Chain Length ◽  
Low Grade ◽  
Liquid Hydrocarbons ◽  
Gaseous Products ◽  
Underground Gasification ◽  
Long Chain ◽  
Cooper Basin

In the Permian Cooper Basin, South Australia, in which oil and gas occur in coal-bearing sediments, there appears to be a relation between the degree of low grade metamorphism of the coaly matter and the nature of the hydrocarbons in the reservoirs. Liquid hydrocarbons are not found in areas and at depths where the coals are at the high-rank bituminous stage (88-89% carbon, dry mineral-free); there, methane is the main hydrocarbon present. Oil occurs in association with coals of lower rank (80-85% carbon, dry mineral-free) and it seems possible that underground gasification of the liquid hydrocarbons has occurred under natural conditions during advanced coalification.In order to test this, mixtures of long chain paraffins (C10-C28) and (C16-C31) from Kingfish crude oil (East Gippsland Basin) were heated at various pressures, with and without water at temperatures between 255-375°C with the intention of reproducing in one week reactions which might occur at lower temperatures in sediments during geological time.The formation of gaseous products (C1-C4 hydrocarbons; hydrogen and carbon dioxide), light liquid paraffins (C10-C16) and aromatic hydrocarbons was observed. The average chain length of the long chain hydrocarbons was reduced and the effect was more pronounced with the longer chain (C16-C31) fraction. It is concluded that during extended time at temperatures near 400°F which prevail in the deeper parts of the Cooper Basin, gasification reactions involving progressive chain shortening could be responsible for the absence of liquid hydrocarbons in regions where the coals are of the high-rank bituminous type.

Fracture mapping and modelling in shale-gas target in the Cooper Basin, South Australia

2011 ◽  
Vol 51 (1) ◽  
pp. 397 ◽  
Author(s):  
Guillaume Backé ◽  
Hani Abul Khair ◽  
Rosalind King ◽  
Simon Holford
Keyword(s):  
Shale Gas ◽  
Seismic Data ◽  
Oil And Gas ◽  
South Australia ◽  
Horizontal Stress ◽  
Fracture Network ◽  
Low Permeability ◽  
Lake Area ◽  
Stress Regime ◽  
Cooper Basin

The success story of a shale-gas reserve development in the United States is triggering a strong industry focus towards similar plays in Australia. The Cooper Basin (located at the border of South Australia and Queensland) and the Otway Basin (extending both onshore and offshore South Australia and Victoria) could be prime targets to develop shale-gas projects. The Cooper Basin, a late-Carboniferous to mid-Triassic basin, is the largest onshore sedimentary basin producing oil and gas from tight conventional reservoirs with low permeability. Fracture stimulation programs are used extensively to produce the oil and gas. Furthermore, new exploration strategies are now targeting possible commercial gas hosted in low-permeability Permian shale units. To maximise production, the development of shale-gas prospects requires a good understanding of the: 1. structure of the reservoirs; 2. mechanical properties of the stratigraphy; 3. fracture geometry and density; 4. in-situ stress field; and, 5. fracture stimulation strategies. In this study, we use a combination of seismic mapping techniques–including horizon and attribute mapping, and an analysis of wellbore geophysical logs–to best constrain the existing fracture network in the basins. This study is based on the processing and analysis of a 3D seismic cube–the Moomba Big Lake survey–which is located in the southwestern part of the Cooper Basin. This dataset covers an area encompassing both a structurally complex setting in the vicinity of a major fault to the SE of the survey, and an area of more subtle deformation corresponding to the southernmost part of the Nappamerri Trough. Structural fabrics trending ˜NW–SE and NE–SW, which are not visible on the amplitude seismic data, are revealed by the analysis of the seismic attributes–namely a similarity (equivalent to a coherency cube), dip steering and maximum curvature attributes. These orientations are similar to those of natural fractures mapped from borehole images logs, and can therefore be interpreted as imaging natural fractures across the Moomba-Big Lake area. This study is the first of its kind able to detect possible fractures from seismic data in the Cooper Basin. The methodology developed here can offer new insights into the structure of sedimentary basins and provide crucial parameters for the development of tight reservoirs. In parallel, a tentative forward model of the generation of a fracture network following a restoration of the Top Roseneath horizon was carried out. The relatively good correlation between the fracture orientations generated by the model and the fractures mapped from geophysical data shows that fractures in the Moomba-Big Lake area may have formed during either a N–S compressive principal horizontal stress, or an E–W compressive principal horizontal tectonic stress regime. In addition, the orientations of the fracture interpreted through this study are also compatible with a generation under the present day stress regime described in this part of the basin, with an maximal horizontal stress trending E–W.

A model for bottom‐hole temperature stabilization

Geophysics ◽  
1979 ◽  
Vol 44 (8) ◽  
pp. 1458-1462 ◽  
Author(s):  
M. F. Middleton
Keyword(s):  
South Australia ◽  
Alternative Methods ◽  
Drilling Fluids ◽  
Cylindrical Shape ◽  
Deep Well ◽  
Bottom Hole ◽  
Rectangular Coordinates ◽  
Basal Portion ◽  
Gas Fields ◽  
Cooper Basin

Bottom‐hole temperature (BHT) stabilization is modeled assuming that the mud temperature in a deep well is uniform for several meters above its base and that the basal portion of the well was formed rapidly so that it may be considered to have formed “instantaneously”. Therefore, knowledge of circulation time of the drilling fluids, which is required in many alternative methods of correction for BHT disturbance, is not necessary. Rectangular coordinates are used to describe the geometrical configuration of the well, which often departs from an ideal cylindrical shape due to caving of poorly consolidated formations. True formation temperature can be found by a simple curve‐matching technique if several time‐sequential BHT measurements are available. This technique is successfully applied to BHT data from a number of wells in the Moomba and Big Lake gas fields of the Cooper Basin, South Australia.

scholarly journals Geothermal Repurposing of Depleted Oil and Gas Wells in Italy

Proceedings ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 9
Author(s):  
Elena Soldo ◽  
Claudio Alimonti ◽  
Davide Scrocca
Keyword(s):  
Energy Demand ◽  
Oil And Gas ◽  
Preliminary Investigation ◽  
Mature Stage ◽  
Global Changes ◽  
Gas Wells ◽  
Oil And Gas Fields ◽  
Wide Range ◽  
Oil And Gas Wells ◽  
Gas Fields

The decarbonisation of the energy sector is probably one of the main worldwide challenges of the future. Global changes urge a radical transformation and improvement of the energy-producing systems to meet the decarbonisation targets and a reduction of greenhouse gas emissions. The hydrocarbon industry also contributes to this transition path. In a mature stage of oil and gas fields, the production of hydrocarbons is associated with formation waters. The volume of produced water increases with the maturity of the assets and the geothermal repurposing of depleted oil and gas wells could be an alternative to the mining closure. In the described transition scenario, the geothermal energy seems very promising because of its wide range of applications depending on the temperature of extracted fluids. This flexibility enables us to propose projects inspired by a circular economic vision considering the integration in the territory and social acceptance issues. In Italy, since 1985, 7246 wells have been drilled for hydrocarbon, of which 898 are located onshore with a productive or potentially productive operational status. This paper presents a preliminary investigation of oil and gas fields located onshore in Italian territory based on the available information on temperature distribution at different depths. Then, taking into account the local energy demand, existing infrastructure, and land use of the territory, a conversion strategy for the producing wells is proposed for three case studies.

EXPLORATION HIGHLIGHTS FOR 2006

2007 ◽  
Vol 47 (2) ◽  
pp. 631
Author(s):  
J.E. Blevin
Keyword(s):  
Oil And Gas ◽  
South Australia ◽  
3D Seismic ◽  
Market Demand ◽  
South Wales ◽  
Seismic Acquisition ◽  
Almost All ◽  
2D And 3D ◽  
Exploration Activity ◽  
Carnarvon Basin

Key business indicators show an upward trend in exploration activity in Australia during 2006. The year was marked by fluctuating high oil prices, a strong uptake of acreage in most basins, and increased levels of drilling activity and seismic acquisition. Market demand for product, production infrastructure and the fruition of several development projects have pushed the level of exploration activity in both offshore and onshore basins. Despite this trend and the spread of tenements, almost all petroleum discoveries made during 2006 were located within 15 km of existing (but often undeveloped) fields.The Carnarvon Basin continued to be the focus of most offshore exploration activity during 2006, with the highest levels of 3D seismic acquisition and exploration/appraisal/development drilling in the country. Discoveries in the Carnarvon Basin also covered the broadest range of water depths—extending from the oil and gas discoveries made by Apache on the inboard margin of the Barrow Subbasin, to the deepwater gas discoveries at Clio–1 and Chandon–1 by Chevron. Several large gas discoveries were made in the Carnarvon and Bonaparte basins and provide significant tie-back opportunities to existing and planned infrastructure. The Bonaparte Basin also saw significantly increased levels of 2D and 3D seismic acquisition during 2006. Onshore, the Cooper/Eromanga basins continued to experience the highest level of drilling activity and seismic acquisition, while maintaining an overall high drilling success rate. For the first time in many years, data acquisition also occurred in frontier basins like the Daly (Northern Territory), Darling (New South Wales), Tasmanian (Tasmania) and Faust/Capel basins (Lord Howe Rise region).Coal seam methane (CSM) exploration maintained a strong performance in 2006, particularly in Queensland, while South Australia, Queensland and Victoria continue to lead the way with large tracts of acreage gazetted for geothermal energy exploration.

THE EXPLORATION AND APPRAISAL HISTORY OF THE KATNOOK AND LADBROKE GROVE GAS FIELDS, ONSHORE OTWAY BASIN, SOUTH AUSTRALIA

1992 ◽  
Vol 32 (1) ◽  
pp. 67 ◽  
Author(s):  
K. A. Parker
Keyword(s):  
South Australia ◽  
Subsequent Development ◽  
Hydrocarbon Exploration ◽  
Gas Field ◽  
Water Contact ◽  
Field Development ◽  
Gas Accumulation ◽  
Seismic Acquisition ◽  
History Of ◽  
Gas Fields

The discoveries of the Katnook Field and, later, the Ladbroke Grove Field were significant milestones for hydrocarbon exploration in the southeast of South Australia as well as for the Otway Basin in general. The initial 1987 discovery at Katnook-1 of a relatively shallow gas accumulation in the basal part of the Eumeralla Formation was eclipsed in late 1988 at the Katnook-2 appraisal stage where deeper and more significant gas reserves were discovered in the Pretty Hill Sandstone.Technological improvement, in seismic acquisition, in particular, use of longer offset configurations and higher fold, and in filtering and correction techniques at the processing stage, are discussed in relation to improved geologic understanding. These aspects ultimately led to drilling success in both exploration and appraisal.At the deep Katnook discovery stage several significant problem areas remained unresolved. These related to uncertainties in vertical distribution of gas pay, level of a gas-water contact, and unreliable reserve estimates the result of the inability of conventional log analysis techniques to distinguish gas-bearing from water-bearing sands. Both in the evaluation of Katnook-2 and at the Katnook-3 appraisal stage, expensive cased-hole testing programs were undertaken to determine the size, extent and producibility of the gas accumulation. A key development between drilling Katnook-2 and Katnook-3 was the discovery of carbon dioxide-rich gas at Ladbroke Grove during 1989 in an adjacent structure to the south.The Katnook Field was the first commercial gas field development in the southeast, South Australian part of the Otway Basin, with gas sales commencing in March 1991, within a year of completing field appraisal. The discoveries, and subsequent development, have led to a renewed focus on the Otway Basin as a prospective hydrocarbon province.

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