Synrift evaporite deposition and structural characterization of the onshore Alagoas subbasin

2019 ◽  
Vol 7 (4) ◽  
pp. SH19-SH31
Author(s):  
Gabriela Salomão Martins ◽  
Webster Ueipass Mohriak ◽  
Nivaldo Destro
Keyword(s):  
Structural Characterization ◽  
Oil And Gas ◽  
Hanging Wall ◽  
Structural Evolution ◽  
Gas Production ◽  
North East ◽  
The North ◽  
Half Graben ◽  
Well Data

The Sergipe-Alagoas Basin, situated in the north-east Brazilian margin, has a long tradition of oil and gas production and the presence and distribution of evaporites play an important role in petroleum systems in the basin. However, little research has focused on the structural evolution of the older, synrift evaporitic sections of the basin. We have focused explicitly in the detailed subsurface structural characterization of the rift in the Alagoas subbasin and the distribution of the Early Aptian evaporites. To accomplish this objective, we interpreted selected 2D and 3D seismic and well data located in two areas known as the Varela Low (VL) and Fazenda Guindaste Low (FGL). We identified diverse deformation styles in those two basin depocenters. Our interpretation indicates that VL consists of a half-graben with a significant rollover structure, controlled by two listric northeast–southwest border faults. The deformation in the hanging wall is also accommodated by release faults and minor antithetic faults. In this depocenter, we mapped in the seismic and the well data an older evaporitic sequence within the Coqueiro Seco Fm., known as Horizonte Salt. This evaporitic section occurs in the internal part of the VL half graben, where it is limited by release and antithetic faults. Significant salt strata growing toward the antithetic fault is observed. Whereas, the FGL represents a graben elongated along the north-east direction and is controlled by several types of structures. We recognized normal synthetic and antithetic faults, transfer zones, release faults, and rollover anticlines in the seismic throughout this depocenter. We mapped an evaporitic section within the Maceió Fm., known as Paripueira Salt, which consists of disconnected salt bodies, restricted to the hanging walls of synrift faults.

HALF-GRABEN MODEL FOR THE STRUCTURAL EVOLUTION OF THE FITZROY TROUGH, CANNING BASIN, AND IMPLICATIONS FOR RESOURCE EXPLORATION

1988 ◽  
Vol 28 (1) ◽  
pp. 76 ◽  
Author(s):  
B.J. Drummond ◽  
M.A. Etheridge ◽  
P.J. Davies ◽  
M.F. Middleton
Keyword(s):  
Structural Evolution ◽  
Passive Margin ◽  
Normal Faults ◽  
Canning Basin ◽  
North East ◽  
The North ◽  
Structural Style ◽  
Half Graben ◽  
Resource Exploration ◽  
Transfer Faults

The Fitzroy Trough is a north-west/south-east trending rift along the north-east margin of the Canning Basin. The major crustal extension in the trough occurred in the Middle Devonian to Early Carboniferous. Most idealised cross-sections show down-to-trough normal faults bounding both sides of the trough. In contrast, we show the trough to have a half- graben style, with one side a hinge zone or flexure, and the other side bounded by normal faults. Thus, the basin has marked structural asymmetry. The sense of asymmetry switches several times along strike with the hinged margin on the north-eastern margin in some places and the south-west margin in others. The switching in asymmetry occurs at transfer faults. This structural style is expected in extensional tectonic models where the extension occurs on a detachment surface and is typical of many continental and passive margin rifts. The asymmetry of the Palaeozoic structure has implications for resource exploration because of its influence on facies development in and subsequent structural evolution of the trough. Quite different syn-rift clastic and carbonate facies are expected on faulted and hinged margins of a half-graben. Post-rift subsidence will also be somewhat asymmetric, influencing the carbonate reef geometry in particular. Mesozoic deformation in the basin reactivated many of the Palaeozoic normal and transfer faults, and induced reverse slip up basement surfaces on the hinged margin segments.

Structural Integrity System Based on an Object-Oriented Activity- and Product Model

1993 ◽  
Author(s):  
Morten Lovstad ◽  
Tor G. Syvertsen
Keyword(s):  
Computational Models ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Physical Structure ◽  
Gas Production ◽  
Structural Safety ◽  
Actual State ◽  
Product Model ◽  
The North ◽  
Analysis Models

Abstract Huge steel or reinforced concrete structures in deep waters support the installations for oil and gas production in the North Sea. Steady operations in a hostile environment require that structural safety and integrity is maintained. For rapid evaluation and assessment of structural integrity in case of modifications or urgency situations, Structural Integrity Systems are established, comprising computational models and structural analysis programs. A major problem for structural assessment at short notice is to keep the analysis models updated and consistent with the actual state of the physical structure and the loadings. This paper proposes a layered approach for model integration, which enable maintenance of the models at a high level, from which detailed analysis models are derived in a consistent manner.

scholarly journals Stretching and Contraction of Extensional Basins With Pre-Rift Salt: A Numerical Modeling Approach

2021 ◽  
Vol 9 ◽  
Author(s):  
Pablo Granado ◽  
Jonas B. Ruh ◽  
Pablo Santolaria ◽  
Philipp Strauss ◽  
Josep Anton Muñoz
Keyword(s):  
Hanging Wall ◽  
Structural Evolution ◽  
Extension Rate ◽  
Rift Basins ◽  
Basin Inversion ◽  
Accommodation Space ◽  
Basement Faults ◽  
Original Distribution ◽  
Thrust Belts ◽  
Half Graben

We present a series of 2D thermo-mechanical numerical experiments of thick-skinned crustal extension including a pre-rift salt horizon and subsequent thin-, thick-skinned, or mixed styles of convergence accompanied by surface processes. Extension localization along steep basement faults produces half-graben structures and leads to variations in the original distribution of pre-rift salt. Thick-skinned extension rate and salt rheology control hanging wall accommodation space as well as the locus and timing of minibasin grounding. Upon shortening, extension-related basement steps hinder forward propagation of evolving shallow thrust systems; conversely, if full basin inversion takes place along every individual fault, the regional salt layer is placed back to its pre-extensional configuration, constituting a regionally continuous décollement. Continued shortening and basement involvement deform the shallow fold-thrust structures and locally breaches the shallow décollement. We aim at obtaining a series of structural, stratigraphic and kinematic templates of fold-and-thrust belts involving rift basins with an intervening pre-rift salt horizon. Numerical results are compared to natural cases of salt-related inversion tectonics to better understand their structural evolution.

scholarly journals Structural characterization of eutectic aqueous NaCl solutions under variable temperature and pressure conditions

2015 ◽  
Vol 17 (21) ◽  
pp. 14054-14063 ◽  
Author(s):  
A.-A. Ludl ◽  
L. E. Bove ◽  
A. M. Saitta ◽  
M. Salanne ◽  
T. C. Hansen ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Variable Temperature ◽  
Structural Evolution ◽  
Temperature And Pressure

We analyze the structural evolution of quenched aqueous NaCl solutions under pressure up to 4 GPa.

Development of semi-submersible production vessels and its application to Australian waters

2008 ◽  
Vol 48 (1) ◽  
pp. 241
Author(s):  
Hilde Engelsen ◽  
Henrik Hannus
Keyword(s):  
North Sea ◽  
Environmental Conditions ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
The North ◽  
Hull Design ◽  
Steel Catenary Risers ◽  
Drilling Rigs ◽  
In The Beginning

Semi-submersible platforms have a long history in the North Sea. In the beginning they were used mainly as mobile offshore drilling units, but in the last two decades the permanently moored semi-submersible production vessels have become widely used both as gas processing units and combination oil and gas production vessels. The design of production semi-submersibles evolved from that of drilling rigs, but there have since been significant improvements to the design of the hull and the topside configuration in relation to operational requirements and construction processes. The design methods have also been successfully adapted to areas with different environmental conditions, in combination with steel catenary risers and polyester mooring systems. On recent designs, simplifications of the hull systems are being implemented, which ease operation and enhance the passive safety. Finally, the semi-submersible production vessel’s application to Australian waters is discussed with focus on topside layout, hull design and mooring system design. Environmental conditions offshore northwest Australia are compared to North Sea and Gulf of Mexico conditions, along with vessel class and regulatory requirements.

Browse to Bonaparte stratigraphic evaluation

2013 ◽  
Vol 53 (2) ◽  
pp. 483
Author(s):  
Marcus Lemberger ◽  
James Stockley ◽  
Tim Gibbons
Keyword(s):  
Depositional Environment ◽  
Oil And Gas ◽  
Structural Evolution ◽  
North West ◽  
Integrated Environment ◽  
Public Data ◽  
Wide Range ◽  
Well Data ◽  
The Uk ◽  
Gas Bearing

After an initial 2010 stratigraphic, depositional environment and facies determination study of 75 wells in the Browse Basin, TGS has pushed this high-resolution project north into the Bonaparte Basin area. The study incorporates a further 165 wells located across the Ashmore Platform, Vulcan Sub-basin, Londonderry High, Malita and Calder Grabens, Sahul and Flamingo synclines, Laminara and Flamingo highs, Sahul Platform, Troubadour Terrace, and offshore Petrel Sub-basin areas. This multi-basin project has combined all the selected relevant public data into one interpretation study and is delivered in an integrated environment—wells are standardised and sequences interpreted. Once depositional environment and facies are allocated, multi-element maps are produced showing how the basin environments change through time and structural evolution. Stratigraphic interpretation has determined 37 sequences and 32 associated facies maps. Both Browse Basin (140,000 km2) and Bonaparte Basin (270,000 km2) are relatively less explored and at different ages in their exploration life-cycle. Both have proved to be oil and gas bearing across numerous different stratigraphic ages with a wide range of trapping and reservoir methods. This study aims to further aid North West Shelf exploration by delineating, among other facets, the presence or otherwise of rocks with reservoir and seal potential and by identifying structural elements such as the Petrel Sub-basin salt diapirs. This regional well data stratigraphic approach has been used across all the UK and Norway continental shelf hydrocarbon provinces. TGS sees the Australian North West Shelf as a province where this approach will further assist sub-surface understanding, and hence exploration success.

EXPLORATION AND GEOLOGY OF THE WEST SULU BASIN, PHILIPPINES

1974 ◽  
Vol 14 (1) ◽  
pp. 21 ◽  
Author(s):  
R. M. Bell ◽  
R. G. C. Jessop
Keyword(s):  
Oil And Gas ◽  
The Philippines ◽  
The West ◽  
Sulu Sea ◽  
North East ◽  
The North ◽  
Tectonic Events ◽  
Provisional Identification ◽  
Western Portion ◽  
Made In

The West Sulu Basin lies in the western portion of the Sulu Sea. Republic of the Philippines. It occupies an area in excess of 26,000 square miles (67,000 km2) and is bounded to the west and south by the cordilleran arc extending from the island of Palawan through Sabah and along the Sulu Archipelago to the island of Mindanao. To the north-east, the basin probably extends beyond the edge of the continental shelf in Philippine territorial waters.The basin may be broadly divided into a western platform and an eastern deep: the latter is subdivided by northeast-trending basement ridges into three sub-basins. Sediments deposited in these sub-basins are of Tertiary to Recent age and have been affected by several orogenies and by contemporaneous movements of fault-controlled blocks. This has resulted in truncation and the development of marked erosion surfaces and onlap within the Upper Tertiary section. Many anticlinal features mapped within the basin have resulted from drape over basement highs or from penecontemporaneous growth of these highs.Major unconformities associated with Upper Tertiary tectonic events have been recognized onshore. Extrapolation to offshore areas where these events can be seismically mapped has enabled an interpretative geologic model to be built up. Provisional identification of stratigraphic units and their nature have been made using this model.The Upper Tertiary section within the eastern deep is expected to consist of deltaic and paralic reservoir sands interbedded with, grading into and transgressed by deeper water shale and mudstone with good hydrocarbon source potential. Some limestone lenses may be present.The presence of Lower to Middle Miocene diapiric shale and Plio-Pleistocene intrusives coupled with data of variable quality makes seismic interpretation difficult in some areas. However, several large anticlinal features and a number of stratigraphic and combination traps have been located.A non-commercial discovery of oil and gas has been made in the basin.

New Forms of Work and Employment in an `Old Industrial Region'? The Offshore Construction Industry in the North East of England

1994 ◽  
Vol 8 (4) ◽  
pp. 531-552 ◽  
Author(s):  
Andy Cumbers
Keyword(s):  
Labour Market ◽  
Construction Industry ◽  
Oil And Gas ◽  
Evolutionary Process ◽  
The Past ◽  
North East ◽  
The North ◽  
Local Labour ◽  
New Forms Of Work ◽  
Work And Employment

This paper examines the nature of the new forms of work and employment brought to the North East of England by the development of offshore construction activities, serving the North Sea's oil and gas industries in the period since the early 1970s. In particular, it assesses the extent to which these activities differ from traditional forms of work and employment organisation within the region. The results of this analysis suggest the need to interpret contemporary patterns of restructuring, both in a particular local labour market context and more generally, as part of an on-going evolutionary process, rather than as a decisive break (or shift) from the past.

scholarly journals Late Cretaceous basin development of the southern Danish Central Graben

1969 ◽  
Vol 20 ◽  
pp. 15-18
Author(s):  
Finn Jakobsen ◽  
Claus Andersen
Keyword(s):  
Late Cretaceous ◽  
Oil And Gas ◽  
Seismic Inversion ◽  
Gas Production ◽  
Structural Development ◽  
Oil Accumulation ◽  
Oil And Gas Production ◽  
North West ◽  
The North ◽  
Basin Development

The Danish oil and gas production mainly comes from fields with chalk reservoirs of Late Cretaceous (Maastrichtian) and early Paleocene (Danian) ages located in the southern part of the Danish Central Graben in the North Sea. The area is mature with respect to exploration with most chalk fields located in structural traps known since the 1970s. However, the discovery by Mærsk Oil and Gas A/S of the large nonstructurally and dynamically trapped oil accumulation of the Halfdan Field in 1999 north-west of the Dan Field (e.g. Albrechtsen et al. 2001) triggered renewed exploration interest. This led to acquisition of new high quality 3-D seismic data that considerably enhanced imaging of different depositional features within the Chalk Group. Parallel to the endeavours by the operator to locate additional non-structural traps in porous chalk, the Geological Survey of Denmark and Greenland took advantage of the new data to unravel basin development by combining 3-D seismic interpretation of a large number of seismic markers, well log correlations and 2-D seismic inversion for prediction of the distribution of porous intervals in the Chalk Group. Part of this study is presented by Abramovitz et al. (in press). In the present paper we focus on aspects of the general structural development during the Late Cretaceous as illustrated by semi-regional time-isochore maps. The Chalk Group has been divided into two seismically mappable units (a Cenomanian–Campanian lower Chalk Unit and a Maastrichtian–Danian upper Chalk Unit) separated by a distinct basin-wide unconformity.

scholarly journals Descriptive text to the Geological map of Greenland, 1:100 000, Kilen 81 Ø.1 Syd

2018 ◽  
pp. 1-29
Author(s):  
Kristian Svennevig ◽  
Peter Alsen ◽  
Pierpaolo Guarnieri ◽  
Jussi Hovikoski ◽  
Bodil Wesenberg Lauridsen ◽  
...  
Keyword(s):  
Hanging Wall ◽  
Field Work ◽  
Normal Faults ◽  
The South ◽  
Thrust Sheet ◽  
Basin Inversion ◽  
North East ◽  
The North ◽  
Geological Map ◽  
Surrounding Areas

The geological map sheet of Kilen in 1:100 000 scale covers the south-eastern part of the Carboniferous– Palaeogene Wandel Sea Basin in eastern North Greenland. The map area is dominated by the Flade Isblink ice cap, which separates several minor isolated landmasses. On the semi-nunatak of Kilen, the map is mainly based on oblique photogrammetry and stratigraphical field work while in Erik S. Henius Land, Nordostrundingen and northern Amdrup Land the map is based on field data collected during previous, 1:500 000 scale regional mapping. Twenty-one Palaeozoic–Mesozoic mappable units were identified on Kilen, while the surrounding areas comprise the Late Cretaceous Nakkehoved Formation to the north-east and the Late Carboniferous Foldedal Formation to the south-west. On Kilen, the description of Jurassic–Cretaceous units follows a recently published lithostratigraphy. The Upper Palaeozoic–lowermost Cretaceous strata comprise seven formations and an informal mélange unit. The overlying Lower–Upper Cretaceous succession comprises the Galadriel Fjeld and Sølverbæk Formations, which are subdivided into six and five units, respectively. In addition, the Quaternary Ymer Formation was mapped on south-east Kilen. The Upper Palaeozoic to Mesozoic strata of Kilen are faulted and folded. Several post-Coniacian NNW–SSE-trending normal faults are identified and found to be passively folded by a later N–S compressional event. A prominent subhorizontal fault, the Central Detachment, separates two thrust sheets, the Kilen Thrust Sheet in the footwall and the Hondal Elv Thrust Sheet in the hanging wall. The style of deformation and the structures found on Kilen are caused by compressional tectonics resulting in post-extensional, presumably Early Eocene, folding and thrusting and basin inversion. The structural history of the surrounding areas and their relation to Kilen await further studies.

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