WAXINGS AND WANINGS IN STRATIGRAPHY, PLAY CONCEPTS AND PROSPECTIVITY IN THE CANNING BASIN

1989 ◽  
Vol 29 (1) ◽  
pp. 466
Author(s):  
Barry A. Goldstein
Keyword(s):  
Joint Venture ◽  
Low Cost ◽  
Early Carboniferous ◽  
Source Rocks ◽  
Submarine Fan ◽  
Canning Basin ◽  
Salt Domes ◽  
Reservoir Type ◽  
The Will ◽  
Oil Source

The prospectivity of the Canning Basin is by no means exhausted. Furthermore, low product prices will offer those with the will and the wherewithal some relatively low cost opportunities to drill seismically well- defined, selected plays in selected acreage. There may never be a better time to invest in the Canning Basin.The Canning Basin rock record includes at least 16 distinct regional episodes of onlapping, quiet- water conditions that transgressed higher energy reservoir- type facies. These vertical successions often constitute correctable seismic sequences and represent apt horizons at which to map prospective, shale- capped trap configurations. All of these 16+ top- sealed reservoir levels are associated with oil and/or gas shows in some part of the Canning Basin. Indeed, the majority of Canning Basin wildcats are associated with reports of petroleum shows.There are seven separate petroleum discoveries (four developed) in the Canning Basin. These span seven different formations and three distinctive trap- types: draped bioherms, anticlinal culminations and tilted horsts. While the overall historical ratio of discoveries to wildcats is low (~1:19), the most successful joint venture in the Canning Basin can claim a 1 in 5.3 rate of discovery leading to development since its first wildcat (Blina 1) in 1980.The most effective oil source rocks in the Canning Basin are thought to be Arenigian to Llanvirnian (Ordovician) marine shales, the Givetian to Frasnian (Devonian) Gogo Formation and the Late Devonian to Early Carboniferous Fairfield Group, in particular the Tournaisian Laurel Formation.The most consistently permeable reservoirs that are most frequently in favourable juxtaposition to source rocks and seals are the Permo- Carboniferous glacigenic quartzose sandstones of the Grant Group. Most other Palaeozoic reservoirs that are judged to have adequate top seals are less regularly porous. All significant porosity in carbonates in the Canning Basin is apparently diagenetic and irregularly distributed. Those carbonates most likely to be permeable are leached and/or dolomitised and/or fractured. Regressive carbonates, carbonates interfingering with permeable siliciclastics, carbonates adjacent to major faults, and carbonates that either lie above or are cut by unconformities are those apparently most frequently dolomitised. Fenestrate (especially algal) and oolitic fabrics provide excellent habitats for high levels of secondary dolomite and subsequently leached porosity. The Nita, Mellinjerie (lowermost Pillara), uppermost Nullara and Yellow Drum Formations are those units that most frequently exhibit these characteristics in the Canning Basin.Reefs, salt domes and anticlines have enticed, and will probably continue to attract, explorers to the Canning Basin. Traps including (1) intra- Grant Group palaeo- monadnocks, (2) Carribuddy salt pillows and salt evacuation- related turtle- backs, (3) low- stand submarine fan sandstone complexes in the Frasnian Gogo Formation and (4) tilted horsts at Ordovician levels are additional recognised play types that warrant continued interest and will probably be further explored, if product prices permit.

THE HYDROCARBON POTENTIAL OF THE PALAEOZOIC BASINS OF WESTERN AUSTRALIA

1993 ◽  
Vol 33 (1) ◽  
pp. 123 ◽  
Author(s):  
B. J. Warris
Keyword(s):  
Western Australia ◽  
Early Carboniferous ◽  
Poor Quality ◽  
Source Rocks ◽  
Structural Development ◽  
Hydrocarbon Migration ◽  
North West ◽  
Canning Basin ◽  
Made In ◽  
Carnarvon Basin

There are four main Palaeozoic Basins in Western Australia; the Perth Basin (Permian only), the Carnarvon Basin (Ordovician-Permian), the Canning Basin (Ordovician-Permian) and the Bonaparte Basin (Cambrian-Permian).The Perth Basin is a proven petroleum province with commercially producing gas reserves from Permian strata in the Dongara, Woodada and Beharra Springs gas fields.The Palaeozoic of the Carnarvon Basin occurs in three main sub-basins, the Ashburton, Merlinleigh and Gascoyne Sub-basins. No commercial petroleum discoveries ahve been made in these basins.The Canning Basin can be divided into the southern Ordovician-Devonian province of the Willara and Kidson sub-basins and Wallal Embayment and Anketell Shelf, and the northern Devonian-Permian province of the Fitzroy and Gregory sub-basins. Commercial production from the Permo-Carboniferous Sundown, Lloyd, West Terrace, Boundary oilfields and from the Devonian Blina oilfield is present only in the Fitzroy sub-basins.The Bonaparte Basin contains Palaeozoic strata of Cambrian-Permian age but only the Devonian-Permian is considered prospective. Significant but currently non-producing gas discoveries have been made in the Permian of the Petrel and Tern offshore gas fields.Based on the current limited well control, the Palaeozoic basins of Western Australia contain excellent marine and non marine clastic reservoirs together with potential Upper Devonian and Lower Carboniferous reefs. The dominantly marine nature of the Palaeozoic provides thick marine shale seals for these reservoirs. Source rock data is very sparse but indicates excellent gas prone source rocks in the Early Permian and excellent—good oil prone source rocks in the Early Ordovician, Late Devonian, Early Carboniferous and Late Permian.Many large structures are present in these Palaeozoic basins. However, most of the existing wells were drilled either off structure due to insufficient and poor quality seismic or on structures formed during the Mesozoic which postdated primary hydrocarbon migration from the Palaeozoic source rocks.With modern seismic acquisition and processing techniques together with a better understanding of the stratigraphy, structural development and hydrocarbon migration, the Palaeozoic basins of Western Australia provide the explorer with a variety of high risk, high potential plays without the intense bidding competition currently present along the North West Shelf of Australia.

scholarly journals Effective source rock selection and oil–source correlation in the Western Slope of the northern Songliao Basin, China

2021 ◽  
Vol 18 (2) ◽  
pp. 398-415
Author(s):  
He Bi ◽  
Peng Li ◽  
Yun Jiang ◽  
Jing-Jing Fan ◽  
Xiao-Yue Chen
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Thermal Evolution ◽  
Songliao Basin ◽  
Source Rocks ◽  
Crude Oils ◽  
Western Slope ◽  
Geochemical Parameters ◽  
Group I ◽  
Oil Source

AbstractThis study considers the Upper Cretaceous Qingshankou Formation, Yaojia Formation, and the first member of the Nenjiang Formation in the Western Slope of the northern Songliao Basin. Dark mudstone with high abundances of organic matter of Gulong and Qijia sags are considered to be significant source rocks in the study area. To evaluate their development characteristics, differences and effectiveness, geochemical parameters are analyzed. One-dimensional basin modeling and hydrocarbon evolution are also applied to discuss the effectiveness of source rocks. Through the biomarker characteristics, the source–source, oil–oil, and oil–source correlations are assessed and the sources of crude oils in different rock units are determined. Based on the results, Gulong and Qijia source rocks have different organic matter primarily detrived from mixed sources and plankton, respectively. Gulong source rock has higher thermal evolution degree than Qijia source rock. The biomarker parameters of the source rocks are compared with 31 crude oil samples. The studied crude oils can be divided into two groups. The oil–source correlations show that group I oils from Qing II–III, Yao I, and Yao II–III members were probably derived from Gulong source rock and that only group II oils from Nen I member were derived from Qijia source rock.

The Conversion Conundrum: The State and Federal Response to Hospitals’ Changes in Charitable Status

1997 ◽  
Vol 23 (2-3) ◽  
pp. 221-250
Author(s):  
Lawrence E. Singer
Keyword(s):  
Joint Venture ◽  
Low Cost ◽  
State Level ◽  
The State ◽  
Nonprofit Hospitals ◽  
For Profit ◽  
Tax Exempt ◽  
Federal Response ◽  
Profit Status ◽  
Hospital Conversions

The pressures encountered by hospitals in the current era of reimbursement declines and stiffened competition are well known. As the “ultimate” payors—primarily employers and government—aggressively continue to seek low cost care, the response of the hospital industry has been to move toward consolidation and efficiency-enhancing mechanisms.Increasingly, nonprofit, tax-exempt hospitals have come to believe that they are at a significant disadvantage vis-á-vis their for-profit brethren in their ability to attract the capital needed to compete in the market. A growing trend among nonprofit hospitals, therefore, is to sell to or enter into a joint venture with a proprietary organization, or alternatively to convert to for-profit status. In 1995, fifty-eight nonprofit hospitals became for-profit; hospital conversions to for-profit status in 1996 are projected to outstrip the pace established the prior year.The conversion trend has not gone unnoticed at the state level. Recently, several states have proposed or enacted laws regulating sales and conversions of nonprofit hospitals, and many more states are contemplating such legislation.

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.

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.

scholarly journals Study on Geochemical Characteristics of tight sandstone gas accumulation in Linxing area

2020 ◽  
Vol 206 ◽  
pp. 01017
Author(s):  
Yangbing Li ◽  
Weiqiang Hu ◽  
Xin Chen ◽  
Litao Ma ◽  
Cheng Liu ◽  
...  
Keyword(s):  
Source Rock ◽  
Ordos Basin ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Light Hydrocarbons ◽  
Tight Sandstone ◽  
Source Type ◽  
Reservoir Type ◽  
Sandstone Reservoir ◽  
Main Component

Based on the comprehensive analysis of the characteristics of tight sandstone gas composition, carbon isotope, light hydrocarbons and source rocks in Linxing area of Ordos Basin, the reservoir-forming model of tight sandstone gas in this area is discussed. The study shows that methane is the main component of tight sandstone gas, with low contents of heavy hydrocarbons and non-hydrocarbons, mainly belonging to dry gas in the Upper Paleozoic in Linxing area. The values of δ13C1, δ13C2 and δ13C3 of natural gas are in the ranges of -45.6‰ ~ -32.9‰, -28.9‰ ~ -22.3‰ and -26.2‰~ -19.1‰, respectively. The carbon isotopic values of alkane gas show a general trend of positive carbon sequence. δ13C1 value is less than -30‰, with typical characteristics of organic genesis. There is a certain similarity in the composition characteristics of light hydrocarbons. The C7 series show the advantage of methylhexane, while the C5-7 series mainly shows the advantage of isoalkane. The tight sandstone gas in this area is mainly composed of mature coal-derived gas, containing a small amount of coal-derived gas and oil-type gas mixture. According to the mode of hydrocarbon generation, diffusion and migration of source rocks in Linxing area, the tight sandstone gas in the study area can be divided into three types of reservoir-forming assemblages: the upper reservoir type of the far-source type (upper Shihezi formation-shiqianfeng formation sandstone reservoir-forming away from source rocks), the upper reservoir type of the near-source type ( the Lower Shihezi formation sandstone reservoir-outside the source rock), and the self-storage type of the source type (Shanxi formation-Taiyuan formation source rock internal sand reservoir).

Nature and evolution of metamorphic fluids associated with turbidite-hosted gold deposits: Hill End goldfield, NSW, Australia

1993 ◽  
Vol 57 (388) ◽  
pp. 423-436 ◽  
Author(s):  
P. K. Seccombe ◽  
J. Ju ◽  
A. S. Andrew ◽  
B. L. Gulson ◽  
K. J. Mizon
Keyword(s):  
Lead Isotope ◽  
Early Carboniferous ◽  
Gold Deposits ◽  
Source Rocks ◽  
Gold Deposition ◽  
Vein Quartz ◽  
Sulphur Isotope ◽  
Hydrous Minerals ◽  
Vein Formation ◽  
The Hill

AbstractThe Hill goldfield, NSW, Australia, is an example of a syntectonic, slate-belt gold deposit formed in a multiply deformed, Late Silurian slate-metagreywacke turbidite sequence. Gold is confined to bedding-parallel veins and discordant leader veins composed of as many as four generations of quartz, accompanied by phyllosilicates, carbonates and minor sulphides. Vein formation and gold deposition was apparently synchronous with Early Carboniferous metamorphism and deformation. Homogenisation temperatures (Th) for fluid inclusions in vein quartz demonstrate five groupings in the temperature intervals 350-280°C 280-250°C 250-190°C 190-150°C and 150-110°C corresponding to a variety of primary and secondary inclusions developed during four periods of vein quartz deposition under a generally declining temperature regime. Inclusion fluids are characterised by a low salinity of around 0.1 to 3.6 wt. % NaCl equivalent. The dominant gas phase present in the inclusion fluids varies from N2 in the early stages of the paragenesis, through CH 4 during the main episode of gold deposition, to CO2- rich fluids associated with late-stage mineralisation. δ18O values for vein quartz (range 15.1-17.1‰) and vein carbonate (range 11.3-13.4‰) are typical of metamorphic mineralisation. δD composition of hydrous minerals and inclusion fluids (range −53 to −138‰) suggest an influx of meteoric water in the later mineralising fluids. This conclusion is supported by δ13C data for vein calcite (range −2.5 to −9.7%0). δ34S composition of vein pyrrhotite and pyrite ranges from 6.9 to 7.8‰ early in the paragenesis, to lighter values (around 4.2 to 5.8%0) accompanying late gold deposition from more oxidising fluids. Sulphur isotope data imply a sulphur source from underlying turbidites and an increase in fluid oxidation state during mineralisation . Lead isotope measurements on vein pyrite, arseno py rite, galena and gold are characterised by two isotope populations with 207Pb/206Pb ratios of 0.862 and 0.860, which define two discrete mineralising events during vein formation. Consistency between data from vein minerals and lead isotope signatures for potential source rocks indicate that lead was derived from the sedimentary pile.

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