THE INTRA-LATROBE PLAY : A CASE HISTORY FROM THE BASKER/MANTA BLOCK (VIC/P19), GIPPSLAND BASIN

1988 ◽  
Vol 28 (1) ◽  
pp. 100
Author(s):  
A.B.S. Clark ◽  
B.M. Thomas
Keyword(s):  
Large Scale ◽  
Fault Plane ◽  
Sedimentary Facies ◽  
Source Rocks ◽  
Economic Viability ◽  
Burial Depth ◽  
The North ◽  
North Eastern ◽  
Limiting Parameters ◽  
Gippsland Basin

In 1981 Shell and its co-venturers were the successful applicants for gazettal block V80-3, now permit VIC/P19, on the north-eastern margin of the Gippsland Basin where, subsequently, 10 exploration wells were drilled. At the time of the award, the offshore Gippsland Basin had been explored for some 20 years, and the conventional 'Top Latrobe' play even then was considered to be largely exhausted although a few small traps of doubtful economic viability remained untested. Thus, from the outset, exploration in VIC/P19 also emphasised the intra-Latrobe play. While the existence of the intra-Latrobe play has long been recognised, its extent and limiting parameters are less well documented.Recent exploration results in the southern part of VIC/P19 indicate that the main phase (peak) of generation and expulsion of hydrocarbons from intra- Latrobe source rocks occurs at depths of 4 to 5 km for oil and 5 to 6 km for gas. Large-scale vertical migration of hydrocarbons (up to 2 km or more) is probably occurring in many parts of the central Gippsland Basin and has charged faulted intra- Latrobe traps, such as found at Basker-1 and Manta-1. These accumulations are characterised by multiple stacked reservoirs (fluvial and alluvial sandstones) and thin hydrocarbon columns. However, similar adjacent traps are dry, despite the presence of equivalent reservoirs (e.g. Basker South-I and Chimaera-I), probably due to inadequate lateral fault seals. Lateral sealing may occur along the fault plane itself or by favourable juxtaposition of lithologies, both cases being demonstrated in the Manta accumulation. The petrology and reservoir characteristics of Latrobe Group sandstones vary considerably, depending largely on sedimentary facies. Sands of fluvial or alluvial origin are generally inferior to those deposited in shoreline environments. An effective intra-Latrobe reservoir 'floor' lies at around 4 km burial depth for both fluvial and alluvial sandstones.

scholarly journals No Country for Men: Searching for Late Medieval Submerged Settlements in the North-Eastern Zuiderzee Area in the Netherlands

2019 ◽  
Vol 22 (4) ◽  
pp. 567-587 ◽  
Author(s):  
Yftinus T. van Popta
Keyword(s):  
The Netherlands ◽  
Cultural Landscape ◽  
Large Scale ◽  
Interdisciplinary Approach ◽  
Economic Networks ◽  
Late Medieval ◽  
Maritime Cultural Landscape ◽  
The North ◽  
Maritime Culture ◽  
North Eastern

This article focuses on the maritime cultural landscape of the former Zuiderzee (ad 1170–1932) in the central part of the Netherlands. Since the large-scale reclamations from the sea (1932–1968), many remains have been discovered, revealing a submerged and eroded late medieval maritime culture, represented by lost islands, drowned settlements, cultivated lands, shipwrecks, and consequently socio-economic networks. Especially the north-eastern part of the region, known today as the Noordoostpolder, is testimony to the dynamic battles of the Dutch against the water. By examining physical and immaterial datasets from the region, it is possible to give a modern-day idea of this late medieval maritime cultural landscape. Spatial distribution and densities of late medieval archaeological remains are analysed and compared to historical data and remote sensing results. This interdisciplinary approach has led to the discovery of the remains of the drowned settlement of Fenehuysen.

scholarly journals Stratigraphic organisation of the Jurassic sequence in Interior Oman, Arabian Peninsula

GeoArabia ◽  
2006 ◽  
Vol 11 (1) ◽  
pp. 17-50 ◽  
Author(s):  
Mathieu Rousseau ◽  
Gilles Dromart ◽  
Henk Droste ◽  
Peter Homewood
Keyword(s):  
Middle Jurassic ◽  
Large Scale ◽  
Geometric Model ◽  
Sedimentary Facies ◽  
Source Rocks ◽  
Correlation Technique ◽  
Well Log ◽  
Angular Unconformity ◽  
Stratigraphic Model ◽  
Jurassic Sequence

ABSTRACT A Stratigraphic model is proposed for the Jurassic sequence in Interior Oman. The model is based on regional well-log correlations, outcrop analysis and integration of Biostratigraphy. Large-scale architectures are restored using a well-to-well correlation technique, after the well-log markers of the relevant surfaces of sequence stratigraphy are identified. This identification is achieved by comparing well-log signatures to lithological and sedimentological columns of nearby exposed sections. The subsurface dataset consists of 19 wells arranged in two east-west profiles, 341 km and 332 km long. The Jurassic sequence in Interior Oman shows a general easterly thinning wedge and includes two hiatuses with marked age-gaps. Three major depositional episodes are identified: (1) a Pliensbachian-Toarcian coastal encroachment in a southward direction, represented by the dominantly clastic deposition of the Lower Mafraq Formation upon the Permian carbonates; (2) a general late Bajocian marine flooding (hybrid facies of marginal-marine environments of the Upper Mafraq Formation), followed through the Bathonian-Callovian by the carbonate Dhruma-Tuwaiq System which evolved through time from a low-angle, homoclinal ramp dipping in a (north) westwards direction, to a purely aggradational, flat-topped platform (upper Dhruma and Tuwaiq Mountain formations); (3) a Kimmeridgian-Tithonian onlap in an eastwards direction of finegrained limestones (Jubaila-Rayda) upon the post-Tuwaiq unconformity. Depositional hiatuses in the early Liassic and at the Early-Middle Jurassic transition are likely to reflect major eustatic sea-level lowstands. In contrast, subsurface correlations of the MFSs through the Dhruma-Tuwaiq indicate that the post-Tuwaiq unconformity is a low-angle (0.001 degrees) angular unconformity associated with tilting and truncation of the underlying sequences. Oxfordian sequences were probably never deposited in Interior Oman because of a lack of accommodation space and prolonged subaerial exposure. It is here proposed that the Upper/Middle Jurassic angular unconformity in Interior Oman was planed-off by subaerial carbonate dissolution during a steady, tectonically-driven uplift of the whole eastern Arabian shelf edge. The proposed geological model has several implications for the petroleum systems of Interior Oman. The geometric model predicts the distribution of the sedimentary facies, including source rocks, clastic and carbonate reservoirs, and seal facies. The occurrence of isolated Upper Mafraq-producing reservoir sands (i.e. Sayh Rawl field) are believed to be restricted to central and eastern Interior Oman. There are two other reservoir/seal combinations, both related to the Upper/Middle Jurassic unconformity: (1) truncation traps of the Dhruma-Tuwaiq below the unconformity (i.e. Hadriya and Uwainat reservoirs); (2) updip pinch-out trap of the Hanifa above the unconformity. Finally, it is believed that the early Late Jurassic general uplift and truncation of eastern Oman may have caused local remobilisation, updip migration, and loss to the surface of oil in reservoirs, initially generated from the prolific Al Huqf source rocks of Late Precambrian-Early Cambrian age.

AN EARLY CRETACEOUS SOURCE ROCK IN THE KENDREW TERRACE, DAMPIER SUB-BASIN?

1996 ◽  
Vol 36 (1) ◽  
pp. 477 ◽  
Author(s):  
S. Ryan-Grigor ◽  
C. M. Griffiths
Keyword(s):  
Source Rock ◽  
North Sea ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Large Scale ◽  
Free Water ◽  
Organic Content ◽  
Source Rocks ◽  
The North ◽  
Northern North Sea

The Early to Middle Cretaceous is characterised worldwide by widespread distribution of dark shales with high gamma ray readings and high organic contents defined as dark coloured mudrocks having the sedimentary, palaeoecological and geochemical characteristics associated with deposition under oxygen-deficient or oxygen-free bottom waters. Factors that contributed to the formation of the Early to Middle Cretaceous 'hot shales' are: rising sea-level, a warm equable climate which promoted water stratification, and large scale palaeogeographic features that restrict free water mixing. In the northern North Sea, the main source rock is the Late Jurassic to Early Cretaceous Kimmeridge Clay/Draupne Formation 'hot shale' which occurs within the Viking Graben, a large fault-bounded graben, in a marine environment with restricted bottom circulation and often anaerobic conditions. Opening of the basin during a major trans-gressive event resulted in flushing, and deposition of normal open marine shales above the 'hot shales'. The Late Callovian to Berriasian sediments in the Dampier Sub-basin are considered to have been deposited in restricted marine conditions below a stratified water column, in a deep narrow bay. Late Jurassic to Early Cretaceous marine sequences that have been cored on the North West Shelf are generally of moderate quality, compared to the high quality source rocks of the northern North Sea, but it should be noted that the cores are from wells on structural highs. The 'hot shales' are not very organic-rich in the northern Dampier Sub-basin and are not yet within the oil window, however seismic data show a possible reduction in velocity to the southwest in the Kendrew Terrace, suggesting that further south in the basin the shales may be within the oil window and may also be richer in organic content. In this case, they may be productive source rocks, analogous to the main source rock of the North Sea.

Rates of retained and discarded catches from demersal fish trawling off the north-eastern United States

1997 ◽  
Vol 48 (3) ◽  
pp. 185 ◽  
Author(s):  
S. J. Kennelly ◽  
S. C. Drew ◽  
C. D. Delano Gagnon
Keyword(s):  
United States ◽  
Large Scale ◽  
Demersal Fish ◽  
Statistical Analyses ◽  
Individual Species ◽  
Eastern United States ◽  
Spatial And Temporal Patterns ◽  
The North ◽  
North Eastern ◽  
Catch Rates

The retained- and discarded-catch rates of fish, crustaceans and molluscs caught by demersal fish trawlers were quantified in a large-scale observer survey of fleets working off the north-eastern United States. The data presented come from catches sampled from 7757 tows on 1010 fishing trips during the four-year period from July 1990 to June 1994 and are summarized as the weights retained and discarded (per hour of trawling) for many of the important commercial and recreational species in the region. Problems with the spatial and temporal design of the programme restricted statistical analyses of the data and prevented summaries across all statistical areas and months. However, separate summaries for individual areas (over all months) and individual months (over all areas) identified several spatial and temporal patterns in retained- and discarded-catch rates for individual species and combinations of species. Noticeable increases and decreases in catch rates during the four-year period provided information on the relative health of certain stocks, and overall discard percentages indicated relative selectivities of the trawling operations sampled.

scholarly journals Basic characteristics and accumulation mechanism of Sinian−Cambrian giant highly mature and oil-cracking gas reservoirs in the Sichuan Basin, SW China

2017 ◽  
Vol 36 (4) ◽  
pp. 568-590 ◽  
Author(s):  
Bing Luo ◽  
Yu Yang ◽  
Gang Zhou ◽  
Wenjun Luo ◽  
Shujiao Shan ◽  
...  
Keyword(s):  
Natural Gas ◽  
Lower Cambrian ◽  
Sichuan Basin ◽  
Large Scale ◽  
Oil And Gas ◽  
Source Rocks ◽  
Burial Depth ◽  
Sw China ◽  
Accumulation Mechanism ◽  
Oil Cracking

Old Mesoproterozoic−Cambrian successions have been regarded as an important frontier field for global oil and gas exploration in the 21st century. This has been confirmed by a recent natural gas exploration breakthrough in the Sinian and Cambrian strata, central Sichuan Uplift, Sichuan Basin of SW China. However, the accumulation mechanism and enrichment rule of these gases have not been well characterized. This was addressed in this work, with aims to provide important guidance for the further exploration while enriching the general studies of the oil and gas geology in the old Mesoproterozoic–Cambrian strata. Results show that the gas field in the study area is featured by old target layers (Sinian–Lower Cambrian), large burial depth (>4500 m), multiple gas-bearing intervals (the second and fourth members of the Sinian Dengying Formation and the Lower Cambrian Longwangmiao Formation), various gas reservoir types (structural type and structural–lithologic type), large scale (giant), and superimposing and ubiquitous distribution. The giant reserves could be attributed to the extensive intercalation of pervasive high quality source rocks and large-scale karst reservoirs, which enables a three-dimensional hydrocarbon migration and accumulation pattern. The origin of natural gas is oil cracking, and the three critical stages of accumulation include the formation of oil reservoirs in Triassic, the cracking of oil in Cretaceous, and the adjustment and reaccumulations in the Paleogene. The main controlling factor of oil and gas enrichment is the inherited development of large-scale stable paleo-uplift, and the high points in the eastern paleo-uplift are the favorable area for ​natural gas exploration.

scholarly journals KEROGENES KINETIC PARAMETERS INFLUENCE ON THE HYDROCARBONS GENERATION DYNAMICS AND VOLUME BY THE EXAMPLE OF THE UPPER JURASSIC SOURCE ROCKS OF THE NORTH-EASTERN PART OF WEST SIBERIA

2021 ◽  
Vol 2 (1) ◽  
pp. 52-61
Author(s):  
Aleksey A. Deshin ◽  
Svetlana A. Yazikova
Keyword(s):  
Kinetic Parameters ◽  
West Siberia ◽  
Upper Jurassic ◽  
Source Rocks ◽  
One Dimensional ◽  
The North ◽  
Dimensional Modeling ◽  
North Eastern ◽  
North Eastern Part

One-dimensional modeling of four well of the North-Eastern part of West Siberia was conducted. When using kinetic parameters of II type kerogen (Menil-2) and calculated kerogen characteristics for the Upper Jurassic source rocks hydrocarbons generation volume was estimated.

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