Browse Basin sequence stratigraphic study

2012 ◽  
Vol 52 (2) ◽  
pp. 703
Author(s):  
Jim Raggatt ◽  
Tim Gibbons ◽  
James Stockley ◽  
Ian Deighton

In addition to the large gas fields already discovered in the Browse Basin, there is considerable scope for further exploration success because this basin holds an estimated recoverable reserve of 30 tcf gas. TGS has completed the Browse Basin Sequence stratigraphic study to specifically understand the many depositional environments of this basin by a comprehensive analysis of 75 key wells all tied to extensive 2D seismic interpretation. With a standardized lithostratigraphic and chronostratigraphic interpretation, each well has a full 3rd order sequence boundary record across all logged sections, and was subsequently assigned detailed gross depositional environments (GDE). Tied to the GDE’s are specific and highly detailed facies associations, displayed in 26 facies maps, thereby building a robust multi-sequence geological model constrained by sequences. These basin-wide facies maps delineate known source, reservoir and seal and propose where—within the robust geological model—potentially similar facies have been deposited and preserved. This extended abstract is delivered by the Facies Map Browser (FMB), a unique product, containing all data and interpreted maps. The Browse Basin FMB allows users to quickly understand the basin-wide depositional history and interpreted facies. With the multi-well and multi-source background database, the FMB product has proven to shorten the exploration cycle by its sheer level of detail and wide ranging interpretation.

2019 ◽  
Vol 156 (10) ◽  
pp. 1715-1741 ◽  
Author(s):  
Jake Breckenridge ◽  
Angelos G. Maravelis ◽  
Octavian Catuneanu ◽  
Kevin Ruming ◽  
Erin Holmes ◽  
...  

AbstractAn integrated study of sedimentological, sequence-stratigraphic and palaeodispersal analysis was applied to the Upper-Permian clastic sedimentary succession in the Northern Sydney Basin, Australia. The succession is subdivided into fifteen facies and three facies associations. The facies associations are further subdivided into eight sub-facies associations. The sedimentary evolution involves progradation from delta-front to delta-plain to fluvial depositional environments, with a significant increase in sediment grain size across the unconformable contact that separates the deltaic from the overlying fluvial system. In contrast to the delta front that is wave/storm- and/or river-influenced, the delta plain is significantly affected by tides, with the impact of tidal currents decreasing up-sequence in the delta plain. The general lack of wave-influenced sedimentary structures suggests low wave energy in the delta plain. The abrupt termination of the tidal impact in the fluvial realm relates to the steep topographic gradients and high sediment supply, which accompanied the uplift of the New England Orogen. The sequence-stratigraphic framework includes highstand (deltaic forest and topset) and lowstand (fluvial topset) systems tracts, separated by a subaerial unconformity. In contrast to most of the mud-rich modern counterparts, this is an example of a sand-rich tidally influenced deltaic system, developed adjacent to the source region. This investigation presents a depositional model for tidal successions in regions of tectonic uplift and confinement.


ISRN Geology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ntokozo Malaza ◽  
Kuiwu Liu ◽  
Baojin Zhao

The late Palaeozoic coal-bearing Madzaringwe Formation of the Karoo Supergroup in the Tshipise-Pafuri Basin in the Limpopo Province, South Africa, records part of the infill of a passive continental margin terrain. Lithofacies analysis was performed with a view to deduce the nature of depositional environments of the Formation. Sedimentological and sequence stratigraphic evidence indicates that this unit represents a complex siliciclastic facies that reflects a fluvial paleodepositional environment. Eleven facies, which were grouped into five facies associations, were recognised. The base of the Madzaringwe Formation (Lower Member) represents a sequence deposited by braided channels. The coal deposits represent flood plain and swamp deposits, which is characterised by shale, thick coal seams, siltstone, and sandstone. The Middle Member is characterised by both clast and matrix supported conglomerates, major tubular and lenticular sandstones, and finely calcareous, micaceous siltstone. The deposition represents a sequence being formed from fluvial and particularly braided channels. The crudely stratified, coarse to pebbly sandstone indicates channel lag deposits within a heavy loaded fluvial system. The fine-grained sandstone represents deposition by shift channel and side bar deposits during lower flow conditions. The Upper Member is characterised by facies associations similar to the Lower Member, representing a new depositional cyclothem.


GeoArabia ◽  
2013 ◽  
Vol 18 (4) ◽  
pp. 17-44 ◽  
Author(s):  
Marlene Maria-Louise Haase ◽  
Thomas Aigner

ABSTRACT This study is part of a large-scale outcrop analog study on Middle Permian to Lower Triassic Khuff-equivalent strata in the Oman Mountains, Al Jabal al-Akhdar, Sultanate of Oman. The Khuff outcrop equivalent can be divided into six sequences (Khuff sequences KS6 to KS1, from base to top). The main focus of this study is the description of the internal anatomy of the shoal grainstone bodies in the lower part of Sequence KS4 (“lower KS4”). High-resolution sedimentological logging of three outcrop sections in wadis Sahtan, Bani Awf and Mistal yielded eight lithofacies types that were grouped into five facies associations. Lower KS4 strata were mainly deposited within a “shoal complex” of an epeiric carbonate ramp, resulting in a thick pile of up to 70 m of grainstones that, on first sight, appear relatively homogeneous. However, detailed facies and microfacies analysis revealed their heterogeneous architecture on various scales: (1) Minor changes in depositional environments directly affected the type of carbonate grains (ooids versus peloids/cortoids versus bioclasts), leading potentially to highly variable pore systems (moldic versus interparticle versus intraparticle). (2) Vertically, detailed sequence-stratigraphic analysis revealed a higher-order of cyclicity (“mini-cycles”) on a decimeter- to meter-scale. Four mini-cycle types were recognized. (3) Laterally, facies changes, the amalgamation of grainstone beds and mini-cycle pinch-outs were observed in 2-D correlations on a scale of a few kilometers. These different types of heterogeneities may contribute to varying production rates commonly observed in the subsurface KS4 reservoir.


Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 273
Author(s):  
Sean Melehan ◽  
Chrysanthos Botziolis ◽  
Angelos G. Maravelis ◽  
Octavian Catuneanu ◽  
Kevin Ruming ◽  
...  

This study integrates sedimentological and stratigraphic insights into the Upper Permian sedimentary rocks of the Wittingham, Tomago and Newcastle Coal Measures in the Northern Sydney Basin, Australia. Facies analysis documented fifteen facies that belong to seven facies associations. These facies associations correspond to different depositional environments and sub-environments including prodelta, delta-front, upper, lower delta-plain and fluvial. The stratigraphic development points to a shallowing upward trend and is reflected with fluvial deposits sitting on top of the deltaic deposits. The fluvio-deltaic contact is represented by an unconformity and displays an upward increase in sediment caliber. The delta front is mainly controlled by wave, storms- and/or river currents, even though the contribution of tides also occurs in the form of sedimentary structures that suggest tidal influence. In contrast, prodelta and delta-plain are significantly modulated by tidal currents. The impact of tides in the delta plain is fading away upward and therefore, the upper delta plain is much less impacted compared to the lower delta plain. The low abundance of wave ripples suggests that the wave action was not very important in the delta plain. Steep topographic gradients and increased sediment input are suggested, based on the limited or absent evidence of tides in the fluvial realm, related to the growing New England Orogen. In sequence stratigraphic terms, the deltaic system accumulated during highstand normal regression, while the deposition of the overlying fluvial system occurred during lowstand normal regression. The two systems are separated by a subaerial unconformity developed during an intervening forced regression. Short periods of transgression are inferred from the presence of higher frequency cycles in the delta-front.


GeoArabia ◽  
2008 ◽  
Vol 13 (3) ◽  
pp. 39-120 ◽  
Author(s):  
Peter Homewood ◽  
Philippe Razin ◽  
Carine Grélaud ◽  
Henk Droste ◽  
Volker Vahrenkamp ◽  
...  

ABSTRACT This field guide describes eleven outcrops of the Natih Formation in the Al Jabal al Akhdar-Jabal Shams and Adam Foothills areas, not far from Nizwa, at the foot of the Oman Mountains. The outcrops have been chosen for their accessibility, as well as for the fairly complete picture of the Natih Formation, which they piece together. To visit all eleven outcrops requires several days and the use of 4-wheel-drive vehicles, but the locations offer no serious physical difficulty, nor long hiking, to gain access. The outcrop descriptions follow in stratigraphic order from the lower to the upper Natih members, roving back-and-forth across the outcrop area. Much of the detailed account of the sedimentology and stratigraphy of the Natih that has been used as the basis of this field guide, has been given previously by van Buchem et al. (1996, 2002), Grélaud (2005), Schwab et al. (2005) and Grélaud et al. (2006). The observations and interpretations given here come in part from those studies, but this paper is also largely the product of a subsequent project that was carried out for the Fahud Studies Team of Petroleum Development Oman (PDO), to provide detailed sedimentology and high-resolution sequence stratigraphy of the Natih Formation for further development of the Fahud field (Homewood et al. 2006). In this respect, this field guide is not so much intended to be an original contribution in terms of the science concerning the Natih Formation. The intent is to provide the ways-and-means for all to gain a first-hand personal understanding of the rocks we have enjoyed working on. Following the outcrop descriptions, a general section provides a discussion on facies and facies associations in terms of the constraints of sequence stratigraphy, sea-level change and clay influx on the carbonate factory. With the incorporation of limited subsurface seismic and well data, geobodies and depositional assemblages, the three-dimensional objects that form the stratigraphic packages at outcrop and seismic scales, respectively, are also discussed. Facies are thus interpreted not only in terms of depositional environments, but are also placed within both geometrical (geobody, depositional assemblage) and sequence-stratigraphic frameworks. In the conclusion, it is argued that a deeper understanding of the Natih Formation has been gained by comparison of outcrop data with subsurface data, and by contrast with modern analogs. The detail required to apply what was learned from outcrop to the nearby subsurface, in a practical manner (but also properly to reconstruct the successive Natih scenarios), requires building several facies models. This is in contrast to giving a single composite picture of Natih facies distribution in space and time, under one single facies model.


GeoArabia ◽  
2005 ◽  
Vol 10 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Moujahed Al-Husseini ◽  
Robley K. Matthews

The recent publication of GTS 2004 (Gradstein et al., 2004) provides an opportunity to recalibrate in time the late Carboniferous, Permian and Early Traissic Arabian Stratigraphy (GeoArabia Special Publication 3, Edited by Al-Husseini, 2004) as represented by the rock units in subsurface Interior Oman (Osterloff et al., 2004a, b) and the Haushi-Huqf Uplift region (Angiolini et al., 2004) (Figure). Additionally, sequence stratigraphic models of orbital forcing (Matthews and Frohlich, 2002; Immenhauser and Matthews, 2004) provide new insights in regards to the time calibration of depositional sequences: the “Rosetta Stone” approach. The Rosetta Stone approach predicts that the period of a third-order depositional sequence is 2.430 ± 0.405 my (denoted DS3 and here adjusted to increase the fourth-order ‘geological tuning fork’ from 0.404 to 0.405 my based on Laskar et al., 2004). The present calibration is also tied to the orbital-forcing model developed by R.K. Matthews (in Al-Husseini and Matthews, 2005; this issue of GeoArabia) that predicts that a second-order depositional sequence (denoted DS2) consists of six DS3s that were deposited in a period of about 14.58 my (6 x 2.430 my); the DS2 being bounded by two regional second-order sequence boundaries (SB2) corresponding to sea-level maximum regression surfaces.


1992 ◽  
Vol 6 ◽  
pp. 176-176
Author(s):  
H. R. Lane ◽  
M. W. Frye ◽  
G. D. Couples

Biothems are regional wedge- or lens-shaped bodies of strata that are: bounded shelfward or cratonward by paleontologically recognizable unconformities; generally thicken on marine shelves, where they are typically conformable with underlying and overlying biothems; are commonly thinner or represent “starved” sequences further basinward; and in their most basinward extent, are either bounded by biostratigraphically recognizable unconformities or are conformable with underlying and overlying biothems. Biothems are practical units whose definition and degree of refinement are dependent on the quality and availability of biostratigraphic control. As recognized to date, biothems have a logical distribution of faunal and floral components, as well as facies groupings that represent internally consistent and logical sequences of depositional environments. The use of biothems as primary sequence stratigraphic units places the emphasis on relative time in a stratigraphic framework.A west-to-east transect within the North American Mississippian System, which extends from the Basin and Range Province, across the Transcontinental Arch (TA) and into the Anadarko Basin, was constructed to demonstrate the regional distribution and tectono-stratigraphic significance of biothems relative to the axis of the TA. The relationships portrayed on the transect, tied to an understanding of North American Mississippian paleogeography, imply that biothems deposited during relative highstand events on one flank of the TA are time-equivalent to biothems deposited during relative lowstand events on the opposite flank of the TA. This distribution is interpreted to have been controlled by intraplate tectonic events that formed “piano-key” basins along the flanks of the TA. The spatial patterns of these basins are not consistent with published models of basin evolution. A further conclusion is that the lack of transgressive or regressive coincident Mississippian biothems on either flank of the TA suggests that it is inadvisable to impose the Mississippi Valley-derived eustasy curve on western flank depositional sequences.


Palaios ◽  
2006 ◽  
Vol 21 (1) ◽  
pp. 86-105 ◽  
Author(s):  
J. S. CRAMPTON ◽  
M. FOOTE ◽  
A. G. BEU ◽  
R. A. COOPER ◽  
I. MATCHAM ◽  
...  

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