Lithofacies analysis and sequence stratigraphy of the Roseneath-Epsilon-Murteree gas plays in the Cooper Basin, South Australia

2017 ◽  
Vol 57 (2) ◽  
pp. 749
Author(s):  
Fengtao Guo ◽  
Peter McCabe
Keyword(s):  
South Australia ◽  
Flood Plain ◽  
X Ray Diffraction ◽  
Sedimentary Evolution ◽  
Facies Associations ◽  
Three Stages ◽  
Mouth Bar ◽  
Mouth Bars ◽  
Stacking Patterns ◽  
Cooper Basin

The early–middle Permian Roseneath-Epsilon-Murteree (REM) strata of the Cooper Basin, South Australia, has conventional and unconventional gas plays. To better understand the sedimentary evolution of the strata, eight key cored wells for the REM in the South Australia were selected and more than 1400 m cores have been characterised to study the lithofacies, facies associations and associated stacking patterns. Twelve lithofacies are identified and further categorised into eight facies associations: (1) open lacustrine, (2) lacustrine shoreface, (3) flood plain/interdistributary bay/channel fill, (4) fluvial channel/distributary channel, (5) crevasse channel/splay/natural levee, (6) distributary mouth bar, (7) prodelta, and (8) mire/swamp. Cyclic stacking patterns are distinguished both in cores and well logs. X-ray diffraction analysis indicates the lower and middle parts of the Murteree Shale mainly consist of claystone and are characteristic of deep water sediments. The upper Murteree Shale has a larger percentage of silt and sand, which suggests an overall regressive process. The Epsilon Formation displays three stages of deposition: (1) a lower, thin, upward-coarsening package of beach and lacustrine shoreline deposits with a continued regression from the underlying Murteree Shale; (2) a coaly, middle unit deposited by distributary channels, crevasse splays, mires and delta mouth bars; and (3) an upper unit of cyclic coarsening-upward claystone, siltstone and sandstone, deposited in shoreline environments with fluvial modifications. The Roseneath Shale resulted from transgression after deposition of the upper Epsilon Formation with a relatively rapid rise of lake level marked by transgressive lags. A final coarsening-upward sequence of shoreline deposits indicates an ending phase of regression.

Internal mouth-bar variability and differential preservation of coastal-process indicators in low-accommodation deltaic settings 

2021 ◽  
Author(s):  
Anna van Yperen ◽  
Miquel Poyatos-Moré ◽  
John Holbrook ◽  
Ivar Midtkandal
Keyword(s):  
Internal Variability ◽  
High Density ◽  
Coastal Processes ◽  
Density Currents ◽  
Sedimentary Characteristics ◽  
Process Regime ◽  
Process Indicators ◽  
Facies Associations ◽  
Mouth Bar ◽  
Mouth Bars

<p>Mouth bars are fundamental architectural elements of deltaic successions. Understanding their internal architecture and complex interaction with coastal processes (fluvial-, tide- and wave-dominated) is therefore paramount to the interpretation of ancient deltaic successions. This is particularly challenging in low-accommodation systems because they are commonly characterized by a thin, condensed and top-truncated expression. In this study we analyze the exhumed Cenomanian Mesa Rica Sandstone (Dakota Group, Western Interior Seaway, USA), which encompasses a fluvio-deltaic system along a ~450 km depositional dip-parallel profile. The study targets the proximal deltaic expression of the system, using 22 sedimentary logs (total of 390 m) spatially correlated within a ~25 km2 study area at the Tucumcari Basin margin. Analysis of facies distribution, depositional architecture and stratigraphic surfaces mapping reveals a 6–10-m-thick, sharp-based and sand-prone deltaic package, comprising several laterally-extensive (>1.4 km width) mouth bars. Within those, we distinguish four different along-strike sub-environments based on differences in grain size, sedimentary structures, bed thicknesses, and bioturbation indices; these are mouth bar axis, off-axis, lateral fringe to distal lateral fringe deposits, and overall reflect waning depositional energy with increasing distality from the distributary channel mouth. The interpreted mouth-bar components also show internal variability in dominant process regime, with overall river dominance but local preservation of tide influence in the lateral fringe and distal fringe environments. However, mouth-bar deposits amalgamate to form an extensive sand-rich sheet body throughout the study area, in which interflood mudstone to very-fine grained sandstone beds are nearly absent. This indicates a low accommodation/supply (A/S) setting, which promoted recurrent channel avulsion/bifurcation and thus reworking of mouth-bar fringe and distal-fringe sediments, where background coastal processes tend to be better recorded.</p><p>Trends in along-strike changes in sedimentary characteristics from axial to lateral environments are also recognized in other wave- and river-dominated deltaic settings as well, where axial components consist of higher energy facies associations resulting from high-density currents, whereas heterolithics become dominant towards the fringes, where there is an alternation of low- and high-density deposits combined with an increased recording of finer-grained facies associations. Complemented with our study, this suggests that internal hierarchy of mouth bars is evident and observed regardless of dominant coastal processes. Consequently, subdivision of mouth bars into different components can reduce complexity of models deriving from a myriad of facies subdivisions, and guide prediction of facies changes and sand distribution in future studies of proximal deltaic settings. Finally, results of this study evidence internal process-regime variability within mouth-bar components. This cautions against relying solely on the preserved deposits at one given location in a system to infer dominant and subordinate coastal processes (e.g. tidal indicators), with a consequent risk of underestimating the true mixed-influence nature of low-accommodation deltaic settings.</p>

THE TIRRAWARRA SANDSTONE AND MERRIMELIA FORMATION OF THE SOUTHERN COOPER BASIN, SOUTH AUSTRALIA — THE SEDIMENTATION AND EVOLUTION OF A GLACIOFLUVIAL SYSTEM

1984 ◽  
Vol 24 (1) ◽  
pp. 377 ◽  
Author(s):  
B. P. J. Williams ◽  
E. K. Wild
Keyword(s):  
South Australia ◽  
Hydrocarbon Potential ◽  
Spatial Evolution ◽  
Fluvial Deposits ◽  
Temporal And Spatial Evolution ◽  
Depositional System ◽  
Facies Associations ◽  
Temporal And Spatial ◽  
The Relationship ◽  
Cooper Basin

An extensive sedimentological study of cores from the Permian Gidgealpa Group of the southern Cooper Basin has produced a new understanding of the relationship between the Tirrawarra Sandstone and the Merrimelia Formation. These two sequences were previously considered to be everywhere separated by a regional unconformity. This study has shown that the facies states, transitions and associations of both formations interdigitate so that typical 'Tirrawarra- type' fluvial deposits are present within glacigenic 'Merrimelia-type' sediments.The Merrimelia Formation was examined regionally in 29 cored wells. Typical facies occurring within the Formation include glaciofluvial outwash, extensive developments of subaerial and subaqueous diamictites, glaciolacustrine ripple-laminated sandstones and siltstones, and thick, monotonous mudrock sequences with clay-dominant rhythmite horizons.The Tirrawarra Sandstone was also examined regionally in 32 cored wells. Four major facies associations were identified within the Sandstone and indicate the temporal and spatial evolution of a fluvioglacial to predominantly fluvial depositional system. Locally the interrelationship between the Tirrawarra Sandstone and the Merrimelia Formation is clearly evident where basal outwash fan deposits of the Tirrawarra Sandstone are interbedded with typical Merrimelia lithotypes. The dominant, low-sinuosity fluvial channel sand facies of the Tirrawarra Sandstone is also an integral part of typical Merrimelia sediment patterns.The Merrimelia Formation and Tirrawarra Sandstone sediments are intimately related and illustrate the evolution of a predominantly glacigenic system into one in which fluvial processes dominate both in time and space. It is evident that no unconformity separates the two sequences and the inclusion of the Merrimelia Formation within the Gidgealpa Group is proposed.A distinct sedlmentological and stratigraphic identity has been assumed in evaluations of the hydrocarbon potential of the Tirrawarra Sandstone. The Merrimelia Formation has been considered generally non-prospective. This study indicates that potential exists for additional reservoirs of 'Tirrawarra type' to be locally developed within the Merrimelia Formation.

Emerging continuous gas plays in the Cooper Basin, South Australia

2012 ◽  
Vol 52 (2) ◽  
pp. 671
Author(s):  
Sandra Menpes ◽  
Tony Hill
Keyword(s):  
Shale Gas ◽  
South Australia ◽  
Flood Plain ◽  
Source Rocks ◽  
Early Permian ◽  
Gas Shale ◽  
Freshwater Lakes ◽  
Gas Desorption ◽  
Wet Gas ◽  
Cooper Basin

Recent off-structure drilling in the Nappamerri Trough has confirmed the presence of gas saturation through most of the Permian succession, including the Roseneath and Murteree shales. Basin-centred gas, shale gas and deep CSG plays in the Cooper Basin are now the focus of an escalating drilling and evaluation campaign. The Permian succession in the Nappamerri Trough is up to 1,000 m thick, comprising very thermally mature, gas-prone source rocks with interbedded sands—ideal for the creation of a basin-centred gas accumulation. Excluding the Murteree and Roseneath shales, the succession comprises up to 45% carbonaceous and silty shales and thin coals deposited in flood plain, lacustrine and coal swamp environments. The Early Permian Murteree and Roseneath shales are thick, generally flat lying, and laterally extensive, comprising siltstones and mudstones deposited in large and relatively deep freshwater lakes. Total organic carbon values average 3.9% in the Roseneath Shale and 2.4% in the Murteree Shale. The shales lie in the wet gas window (0.95–1.7% Ro) or dry gas window (>1.7% Ro) over much of the Cooper Basin. Thick Permian coals in the deepest parts of the Patchawarra Trough and over the Moomba high on the margin of the Nappamerri Trough are targets for deep CSG. Gas desorption analysis of a thick Patchawarra coal seam returned excellent total raw gas results averaging 21.2 scc/g (680 scf/ton) across 10 m. Scanning electron microscopy has shown that the coals contain significant microporosity.

SEISMIC AVO STUDIES ASSIST IN THE MAPPING OF A PERMIAN GAS SAND AT KERNA FIELD, COOPER BASIN

1991 ◽  
Vol 31 (1) ◽  
pp. 244
Author(s):  
J. Pinchin ◽  
A.B. Mitchell
Keyword(s):  
South Australia ◽  
Flood Plain ◽  
Seismic Facies ◽  
Gas Field ◽  
Seismic Modelling ◽  
Coal Beds ◽  
South Central ◽  
Amplitude Versus Offset ◽  
Modelling Studies ◽  
Cooper Basin

Kerna is a gas field within the south-central part of the Cooper Basin, 12 km southwest of the Dullingari Field and adjacent to the border of South Australia and Queensland. The trap is a domal anticline containing gas structurally trapped within the Early Permian Patchawarra Formation. The overlying Permian Epsilon Formation, above intervening shale, also contains gas, which may be stratigraphically trapped or restricted by permeability barriers around the southern and western flanks of the field.Seismic reflection amplitudes can be used to map the extent of the Epsilon gas sand. Seismic modelling studies show that the gas sand displays an amplitude-versus-offset (AVO) effect which distinguishes the gas sand from a wet sand or from a coal reflection at the same stratigraphic level. The spatial distribution of the AVO anomalies, and of the overall seismic stack response, has been mapped across the field. The interpreted 'seismic facies' map shows a meander belt across a coal swamp dominated flood plain. The distribution of AVO anomalies within and around this meander belt shows the likely occurrence of gas-bearing sandstones.This study has implications for other areas of the Cooper Basin where adequate separation between coal beds and gas sands allows the AVO effect of the latter to be observed. These AVO effects can then be used as a direct indicator of gas in stratigraphic and structural traps.

LITHOFACIES STUDY ON THE TOOLACHEE FORMATION, GIDGEALPA-MOOMBA-BIG LAKE AREA, COOPER BASIN, SOUTH AUSTRALIA

1973 ◽  
Vol 13 (1) ◽  
pp. 41
Author(s):  
Roger C. N. Thornton
Keyword(s):  
South Australia ◽  
Flood Plain ◽  
Depositional Environments ◽  
Core Material ◽  
Upper Permian ◽  
Limited Area ◽  
Lake Area ◽  
Opposite Trend ◽  
Flow Gradient ◽  
Cooper Basin

A lithofacies study on the Upper Permian Toolachee Formation has been conducted in the Gidgealpa-Moomba-Big Lake area to determine the suitability of the technique in the reconstruction of depositional environments and palaeogeographic trends throughout the Cooper Basin. The Toolachee Formation is one of the main gas producing intervals in the basin, especially in the area of study, which is approximately 2,000 square kilometres. Thirty-one wells drilled in this region indicate that the formation ranges in thickness from 35 metres to over 115 metres.The Toolachee Formation, taken as a whole, is too thick to show any significant features on a lithofacies map over the limited area of investigation. However, lithofacies maps of three approximately chronostratigraphic subdivisions of the same formation show both vertical and lateral trends. Vertically, the percentage of sandstone decreases from the lowermost subdivision to the uppermost subdivision; coal percentages show the opposite trend; and core material shows fining upwards sequences. Laterally, isopachous thin areas (depositional highs) in most cases correlated with an increase in shale or coal lithologies. Histograms of coal cycles show that the lower and middle parts have similar composite sequences of, from the base upwards, sandstone mixture of sandstone and shale-shalecoal.The depositional model proposed is an aggradational flood-plain which, prior to the commencement of deposition, had been eroded to a peneplain. Sediments were deposited from rivers of gradually declining flow gradient until marsh and lacustrine conditions prevailed for long periods of time. Deposition ceased at the sediplain stage.

GEOLOGY OF THE DELLA FIELD, A PERSPECTIVE ON THE HISTORY OF THE COOPER BASIN

1984 ◽  
Vol 24 (1) ◽  
pp. 266
Author(s):  
D. I. Gravestock ◽  
J. G. G. Morton
Keyword(s):  
South Australia ◽  
Early Permian ◽  
Channel Migration ◽  
Fault Activity ◽  
Facies Associations ◽  
History Of ◽  
Petrophysical Logs ◽  
Fluvial Sandstone ◽  
Active Channel ◽  
Cooper Basin

The Della Field produces dry gas from stacked fluvial sandstone reservoirs in the Early Permian Patchawarra Formation and Late Permian Toolachee Formation. Localised but severe fault activity and erosion in the late Early Permian have resulted in structural and stratigraphic complexities, particularly on the western flank of the field.A detailed study of lithofacies associations from cores has enabled constraints on the resolution of petrophysical logs to be appreciated. Within these constraints major facies associations are mappable across the field. Active channel migration in the Patchawarra Formation resulted in erosion and hence incomplete preservation of the fluvial sequence, which hinders mapping across the field. In contrast, the successive fluvial cycles of the Toolachee Formation are more completely preserved, enabling intrafield and some interfield correlation and mapping. The contrast is due to changing responses of the fluvial regime to prevailing tectonic conditions.A preliminary fluvial facies model, proposed after the first six Della wells, was upgraded during development drilling, with the result that productive reservoirs were successfully predicted. Integration of all available data provides one perspective on the evolution of the Cooper Basin in South Australia.

Synthesis, Characterization and Thermal Behavior of  HYP2O7·3H2O Electrical Properties of  HYP2O7

2021 ◽  
Author(s):  
Rahma Rahzelli Zrelli ◽  
Fathia Chehimi-Moumen ◽  
Dalila Ben Hassen-Chehimi ◽  
Malika Trabelsi-Ayadi
Keyword(s):  
Infrared Spectroscopy ◽  
Electrical Properties ◽  
Complex Analysis ◽  
Optical Band Gap ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
Medium Temperature ◽  
X Ray ◽  
Three Stages

Abstract The synthesis of the diphosphate HYP2O7·3H2O was made via soft chemistry route from evaporation of aqueous solution at room temperature. The obtained compound, was characterized by means of X-ray diffraction (XRD) and infrared spectroscopy (IR). The results showed a high purity phase. IR spectrum of this diphosphate revealed usual signals related to P2O7 diphosphate group and water molecules. The thermal decomposition of the synthesized product by DTA / TG proceeded through four stages leading to the formation of the Y2P4O13 as a final product. On the other hand, its decomposition by CRTA took place in three stages leading to the formation of the anhydrous diphosphate HYP2O7 as a final product. X-ray powder diffraction and infrared spectroscopy were used to identify these materials. Furthermore the electrical properties of the HYP2O7 were investigated through impedance complex analysis. Modest conductivity has been observed in this material at relatively medium temperature range. Activation energy of 0.67 and 1.44 eV, was deduced from the corresponding Arrhenius plot.The optical band gap of the title compound is calculated and found to be 2.71 eV.

Exploring for stratigraphic traps in the Patchawarra Formation, Cooper Basin: an integrated seismic methodology

2018 ◽  
Vol 58 (2) ◽  
pp. 779
Author(s):  
Alexandra Bennett
Keyword(s):  
Complex Geometry ◽  
Imaging Techniques ◽  
South Australia ◽  
Seismic Interpretation ◽  
Seismic Survey ◽  
3D Seismic ◽  
Seismic Resolution ◽  
Seismic Reflectivity ◽  
Seismic Area ◽  
Cooper Basin

The Patchawarra Formation is characterised by Permian aged fluvial sediments. The conventional hydrocarbon play lies within fluvial sandstones, attributed to point bar deposits and splays, that are typically overlain by floodbank deposits of shales, mudstones and coals. The nature of the deposition of these sands has resulted in the discovery of stratigraphic traps across the Western Flank of the Cooper Basin, South Australia. Various seismic techniques are being used to search for and identify these traps. High seismic reflectivity of the coals with the low reflectivity of the relatively thin sands, often below seismic resolution, masks a reservoir response. These factors, combined with complex geometry of these reservoirs, prove a difficult play to image and interpret. Standard seismic interpretation has proven challenging when attempting to map fluvial sands. Active project examples within a 196 km2 3D seismic survey detail an evolving seismic interpretation methodology, which is being used to improve the delineation of potential stratigraphic traps. This involves an integration of seismic processing, package mapping, seismic attributes and imaging techniques. The integrated seismic interpretation methodology has proven to be a successful approach in the discovery of stratigraphic and structural-stratigraphic combination traps in parts of the Cooper Basin and is being used to extend the play northwards into the 3D seismic area discussed.

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