New insights into the deep-water Otway Basin – Part 3. Petroleum system modelling

2021 ◽  
Vol 61 (2) ◽  
pp. 665
Author(s):  
Oliver Schenk ◽  
Emmanuelle Grosjean ◽  
Dianne S. Edwards ◽  
Christopher J. Boreham ◽  
Tekena West ◽  
...  
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Water Area ◽  
Primary Objective ◽  
Depositional Environments ◽  
Petroleum System ◽  
Seismic Survey ◽  
Rift System ◽  
System Modelling ◽  
Quality Of Data

The Otway Basin is a broadly northwest–southeast trending basin and forms part of a rift system that developed along Australia’s southern margin. It represents an established hydrocarbon province with mostly onshore and shallow-water offshore discoveries. However, the outboard deep-water Otway Basin, with water depths up to 6300m, is comparatively underexplored and can be considered a frontier area. Following the completion of a basin-wide seismic depth-imaging program (Part 1) and insights from the revised seismic interpretation (Part 2), we have developed a comprehensive petroleum system modelling (PSM) study by integrating these data and findings (Part 3). Together, the studies have resulted in an improved understanding of the hydrocarbon prospectivity of the deep-water areas of the basin. Given the sparsity of data outboard, almost all legacy PSM studies have been focused either on the onshore or shallow-water areas of the basin and primarily on their thick Lower Cretaceous depocentres. The limitations of legacy seismic datasets resulted in a high degree of uncertainty in the derivative interpretations used as input into PSM studies. In addition, the paucity and poor quality of data in the deep-water area reduced confidence in the understanding of the basin evolution and spatial distribution of depositional environments through time. The newly acquired 2D seismic survey and reprocessed legacy data, with calibration via several wells across the basin, have improved confidence in our understanding of the tectonostratigraphic evolution of the basin (Part 2). The study presented herein integrates products from the work in Part 2 into a petroleum system model with the primary objective being to better understand the petroleum systems across the deep-water Otway Basin.

DEEP-WATER OTWAY BASIN: A NEW ASSESSMENT OF THE TECTONICS AND HYDROCARBON PROSPECTIVITY

2000 ◽  
Vol 40 (1) ◽  
pp. 66 ◽  
Author(s):  
A.M.G. Moore ◽  
H.M.J. Stagg ◽  
M.S. Norvick
Keyword(s):  
Continental Shelf ◽  
Continental Slope ◽  
Deep Water ◽  
South Australia ◽  
Petroleum System ◽  
Hydrocarbon Exploration ◽  
Source Rocks ◽  
Rift System ◽  
Crust And Upper Mantle ◽  
Data Set

The northwest-trending Otway Basin in southeast Australia formed during the separation of Australia and Antarctica between the latest Jurassic and the Early Cainozoic. A new, deep-seismic data set shows that the basin comprises two temporally and spatially overlapping rift components:the mainly Late Jurassic to mid-Cretaceous, east-west trending, inner Otway Basin—comprising the onshore basin and most of the continental shelf basin; andthe northwest–southeast to north–south trending depocentres beneath the outer shelf and continental slope, extending from eastern South Australia to the west coast of Tasmania, and a relatively minor and ill-defined sub-basin underlying the continental rise in water depths greater than about 4,500 m. This rift system was most active from the mid-Cretaceous to Palaeogene, and was strongly affected by sinistral strike-slip motion as Australia and Antarctica separated.The continental slope elements contain the bulk of the sediment volume in the basin. From northwest to southeast, these elements comprise the Beachport and Morum Sub-basins, the north-south trending Discovery Bay High, and the Nelson Sub-basin which appears to be structurally and stratigraphically continuous with the Sorell Basin off west Tasmania.The reflection character of the crust and upper mantle varies widely across the basin, and there is a strong correlation between that character and the basin configuration. It appears that accommodation space beneath the slope basin was created largely by extension and removal of most of the laminated deep continental crust.There is encouragement for hydrocarbon exploration in the deep-water basin. Firstly, there are indications of diagenesis related to fluid flow in and above the strongly faulted Cretaceous section in the Morum Sub-basin. As an Early Cretaceous petroleum system is already proven beneath the continental shelf, this suggests that the same system is also active in deep-water. Secondly, existing sample data suggest that a second, Late Cretaceous petroleum system could be active where any source rocks are sufficiently deeply buried; this condition would probably be met in the Nelson Sub-basin.

Slumps Mass-Transport Deposits in the Brazilian Continental Margin Deep Water: Offshore Potiguar Basin, NE Brazil.

2020 ◽  
Author(s):  
Yoe Perez ◽  
Julia Fonseca ◽  
Helenice Vital ◽  
Andre Silva ◽  
David Castro
Keyword(s):  
Mass Transport ◽  
Continental Slope ◽  
Continental Margin ◽  
Deep Water ◽  
Negative Impact ◽  
Water Area ◽  
Passive Margin ◽  
Rift System ◽  
Potiguar Basin ◽  
Mass Transport Deposits

<p>The Brazilian Continental Margin (BEM) deep-water regions contain important geological features that need advance in their characterization. Mass-transport deposits (MTD) are important not only by their significance in the sedimentary but also because of their negative impact economically. A slump is a coherent mass of sediment that moves on a concave-up glide plane and undergoes rotational movements causing internal deformation and one of the basic types of MTD. The study area comprises part of the offshore Potiguar Basin in NE Brazil, on the distal eastern portion of the Touros High and Fernando de Noronha Ridge. This portion of the Potiguar Basin comprises a transform rift system that has evolved into a continental passive margin. This basin represents an important location related to the breakup between South America and Africa. The database used in this work included 2D post-stack time-migrated seismic profiles from the Brazilian Agency of Petroleum, Natural Gas, and Biofuels (ANP). The slumps reflectors are identified on the continental shelf profiles in form of present clinoform configuration, medium to high continuity, high amplitudes, and medium to high frequencies, representing a sigmoidal oblique complex prograding reflector. The slump scars at the continental slope indicate that this is a gravitationally unstable area that will eventually collapse, resulting in erosional features on the continental slope and deposition on the continental rise. Our results provide some insights regarding MDT slumps sedimentary evolution in the BEM deep water area as well as their interrelation with other sedimentary deposits.</p>

scholarly journals The influence of environmental setting on the community ecology of Ediacaran organisms

2019 ◽  
Author(s):  
Emily G. Mitchell ◽  
Nikolai Bobkov ◽  
Natalia Bykova ◽  
Alavya Dhungana ◽  
Anton Kolesnikov ◽  
...  
Keyword(s):  
Community Ecology ◽  
Shallow Water ◽  
Deep Water ◽  
Benthic Communities ◽  
Bedding Plane ◽  
Depositional Environments ◽  
Time Interval ◽  
Benthic Environment ◽  
A Chain ◽  
Broad Scale

AbstractThe broad-scale environment plays a substantial role in shaping modern marine ecosystems, but the degree to which palaeocommunities were influenced by their environment is unclear. To investigate how broad-scale environment influenced the community ecology of early animal ecosystems we employed spatial point process analyses to examine the community structure of seven bedding-plane assemblages of late Ediacaran age (558–550 Ma), drawn from a range of environmental settings and global localities. The studied palaeocommunities exhibit marked differences in the response of their component taxa to sub-metre-scale habitat heterogeneities on the seafloor. Shallow-marine palaeocommunities were heavily influenced by local habitat heterogeneities, in contrast to their deep-water counterparts. Lower species richness in deep-water Ediacaran assemblages compared to shallow-water counterparts across the studied time-interval could have been driven by this environmental patchiness, because habitat heterogeneities correspond to higher diversity in modern marine environments. The presence of grazers and detritivores within shallow-water communities may have promoted local patchiness, potentially initiating a chain of increasing heterogeneity of benthic communities from shallow to deep-marine depositional environments. Our results provide quantitative support for the “Savannah” hypothesis for early animal diversification – whereby Ediacaran diversification was driven by patchiness in the local benthic environment.Author ContributionsE. Mitchell conceived this paper and wrote the first draft. N. Bobkov, A. Kolesnikov, N. Sozonov and D. Grazhdankin collected the data for DS surface. N. Bobkov and N. Sozonov performed the analyses on DS surface. N. Bykova, S. Xiao, and D. Grazhdankin collected the data for WS, KH1 and KH2 surfaces and E. Mitchell performed the analyses. A. Dhungana and A. Liu collected the data for FUN4 and FUN5 surfaces and A. Dhungana performed the analyses. T. Mustill and D. Grazhdankin collected the data for KS and T. Mustill and E. Mitchell performed the analyses. I. Hogarth developed the software for preliminary KS surface analyses. E. Mitchell, N. Bobkov, N. Bykova, A. Dhungana, A. Kolesnikov, A. Liu, S. Xiao and D. Grazhdankin discussed the results and prepared the manuscript.

scholarly journals IMPLEMENTATION OF SEISMIC SURVEY TECHNOLOGIES WITHINTRANSITION ZONES OF THE NORTH OF WESTERN SIBERIA

2017 ◽  
pp. 11-20
Author(s):  
V. I. Kuznetsov ◽  
Yu. N. Dolgikh
Keyword(s):  
Shallow Water ◽  
Transition Zone ◽  
Western Siberia ◽  
Water Area ◽  
Seismic Survey ◽  
Ecological Safety ◽  
The North ◽  
Shallow Water Area ◽  
Marine Cables

From the viewpoint of seismic survey, transition zone is a shallow water area where it is impossible to use marine cables because of low depth, there are difficulties in terms of coordination between geophones and environment, usage of explosives is prohibited, usage of air guns is ineffective. And besides, there are in-creased requirements concerning ecological safety. In order to solve this problem it is necessary to use multiva-riant systems of emergence, reception and registration, that is complex usage of explosions, surface sources, air guns, bottom and surface geophones and hydrophones. It is necessary to use overlapping and special technolo-gy for combination of data received from different systems and different field seasons (summer, winter).

An integrated approach to understanding the petroleum system of a frontier deep-water area, offshore Japan

2008 ◽  
Vol 14 (3) ◽  
pp. 223-233 ◽  
Author(s):  
Akihiko Okui ◽  
Mitsuyoshi Kaneko ◽  
Satoshi Nakanishi ◽  
Nobuaki Monzawa ◽  
Hiroshi Yamamoto
Keyword(s):  
Deep Water ◽  
Integrated Approach ◽  
Water Area ◽  
Petroleum System ◽  
Deep Water Area

Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin
Keyword(s):  
Deep Water ◽  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Near Surface ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Platform Margin ◽  
Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

A new tool to detect exposure surfaces in shallow water carbonate depositional environments

2002 ◽  
Vol 45 (3) ◽  
pp. 301-317 ◽  
Author(s):  
Andrea Mindszenty ◽  
J. Ferenc Deák ◽  
Mária Fölvári
Keyword(s):  
Shallow Water ◽  
Depositional Environments ◽  
Water Carbonate ◽  
Shallow Water Carbonate
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