scholarly journals Giant meandering channel systems controlled by sediment supply to the deep-water Campos basin

2019 ◽  
Author(s):  
Jacob Covault ◽  
Zoltan Sylvester ◽  
Daniel Carruthers ◽  
Dallas Dunlap
Geosphere ◽  
2021 ◽  
Author(s):  
Jacob A. Covault ◽  
Zoltán Sylvester ◽  
Can Ceyhan ◽  
Dallas B. Dunlap

Submarine channels are conduits for sediment delivery to continental margins, and channel deposits can be sandy components of the fill in tectonically active salt basins. Examples of salt-withdrawal basin fill commonly show successions of sandy channelized or sheet-like systems alternating with more mud-rich mass-transport complexes and hemipelagites. This alternation of depositional styles is controlled by subsidence and sediment-supply histories. Salt-basin fill comprising successions of largely uninterrupted meandering-channel deposition are less commonly recognized. This begs the questions: can sediment supply be large enough to overwhelm basin subsidence and result in a thick succession of channel deposits, and, if so, how would such a channel system evolve? Here, we use three-dimensional seismic-reflection data from a >1500 km2 region with salt-influenced topography in the Campos Basin, offshore Brazil, to evaluate the influence of salt diapirs on an Upper Cretaceous–Paleogene giant meandering submarine-channel system (channel elements >1 km wide; meander wavelengths several kilometers to >10 km). The large scale of the channels in the Campos Basin suggests that sediment discharge was large enough to sustain the meandering channel system in spite of large variability in subsidence across the region. We interpreted 22 channel centerlines to reconstruct the detailed kinematic evolution of this depositional system; this level of detail is akin to that of recent studies of meandering fluvial channels in time-lapse Landsat satellite images. The oldest channel elements are farther from salt diapirs than many of the younger ones; the centerlines of the older channel elements exhibit a correlation between curvature and migration rate, and a spatial delay between locations of peak curvature and maximum migration distance, similar to that observed in rivers. As many of the younger channel centerlines expanded toward nearby salt diapirs, their migration pattern switched to downstream translation as a result of partial confinement. Channel segments that docked against salt diapirs became less mobile, and, as a result, they do not show a correlation between curvature and migration rate. The channel migration pattern in the Campos Basin is different compared to that of a tectonically quiescent continental rise where meander evolution is unobstructed. This style of channelized basin filling is different from that of many existing examples of salt-withdrawal minibasins that are dominated by overall less-channelized deposits. This difference might be a result of the delivery of voluminous coarse sediment and high discharge of channel-forming turbidity currents to the Campos Basin from rivers draining actively uplifting coastal mountains of southeastern Brazil. Detailed kinematic analysis of such well-preserved channels can be used to reconstruct the impact of structural deformation on basin fill.


Author(s):  
Elton J. B. Ribeiro ◽  
Zhimin Tan ◽  
Yucheng Hou ◽  
Yanqiu Zhang ◽  
Andre Iwane

Currently the oil and gas industry is focusing on challenging deep water projects, particularly in Campos Basin located coast off Brazil. However, there are a lot of prolific reservoirs located in shallow water, which need to be developed and they are located in area very far from the coast, where there aren’t pipelines facilities to export oil production, in this case is necessary to use a floating production unit able to storage produced oil, such as a FPSO. So, the riser system configuration should be able to absorb FPSO’s dynamic response due to wave load and avoid damage at touch down zone, in this case is recommended to use compliant riser configuration, such as Lazy Wave, Tethered Wave or Lazy S. In addition to, the proposed FPSO for Tubarão Martelo development is a type VLCC (Very Large Crude Carrier) using external turret moored system, which cause large vertical motion at riser connection and it presents large static offset. Also are expected to install 26 risers and umbilicals hanging off on the turret, this large number of risers and umbilicals has driven the main concerns to clashing and clearance requirement since Lazy-S configuration was adopted. In this paper, some numerical model details and recommendations will be presented, which became a feasible challenging risers system in shallow water. For instance, to solve clashing problem it is strictly recommended for modeling MWA (Mid Water Arch) gutter and bend stiffener at top I-tube interface, this recommendation doesn’t matter in deep water, but for shallow water problem is very important. Also is important to use ballast modules in order to solve clashing problems.


Author(s):  
Jairo Bastos de Araujo ◽  
Roge´rio Diniz Machado ◽  
Cipriano Jose de Medeiros Junior

Petrobras developed a new kind of anchoring device known as Torpedo. This is a steel pile of appropriate weight and shape that is launched in a free fall procedure to be used as fixed anchoring point by any type of floating unit. There are two Torpedoes, T-43 and T-98 weighing 43 and 98 metric tons respectively. On October 2002 T-43 was tested offshore Brazil in Campos Basin. The successful results approved and certified by Bureau Veritas, and the need for a feasible anchoring system for new Petrobras Units in deep water fields of Campos Basin led to the development of a Torpedo with High Holding Power. Petrobras FPSO P-50, a VLCC that is being converted with a spread-mooring configuration will be installed in Albacora Leste field in the second semester of 2004. Its mooring analysis showed that the required holding power for the mooring system would be very high. Drag embedment anchors option would require four big Anchor Handling Vessels for anchor tensioning operations at 1400 m water depth. For this purpose T-98 was designed and its field tests were completed in April 2003. This paper discusses T-98 design, building, tests and ABS certification for FPSO P-50.


2015 ◽  
Vol 45 (2) ◽  
pp. 243-258 ◽  
Author(s):  
Juliana Okubo ◽  
Ricardo Lykawka ◽  
Lucas Veríssimo Warren ◽  
Julia Favoreto ◽  
Dimas Dias-Brito

<p>Carbonate rocks from the Macaé Group (Albian) represent an example of carbonate sedimentation related to the drift phase in Campos Basin. This study presents depositional features, integrating them with diagenetic and stratigraphic aspects of the Macaé Group carbonates including the upper part of the Quissamã Formation and the lower part of the Outeiro Formation. Macroscopic analyses in cores and microscopic ones in thin sections allowed the recognition of eleven sedimentary facies - nine of them corresponding to the Quissamã Formation and two of them representing the Outeiro Formation. These facies were grouped into five facies associations. Oolitic grainstones and oncolitic grainstones are interpreted to be deposited in shallow depth probably in shoals above the fair weather wave base. The interbanks between shoals were formed in less agitated waters and characterized by deposition of peloidal bioclastic packstones and wackestones representative of sedimentation in calm waters. Bioclastic packstones and oolitic packstones/wackestones represent allochthonous deposits related to the beginning of the regional drowning that occur in upper Quissamã Formation. Pithonellids wackestones and bioclastic wackestones with glauconite are related to deep water deposits, characteristics of the Outeiro Formation. Post-depositional features revealed the action of diagenetic processes as, micritization, cimentation, dissolution, compaction, dolomitization and recrystallization occurred during the eo- and mesodiagenesis phases. Vertical facies analysis suggests shallowing upward cycles stacked in a sequence progressively deeper towards the top (from the Quissamã Formation to the Outeiro Formation).</p>


2018 ◽  
Vol 45 (1) ◽  
pp. 99-110
Author(s):  
Hongquan KANG ◽  
Jinluo MENG ◽  
Tao CHENG ◽  
Huaicun JIA ◽  
Bo BAI ◽  
...  

2021 ◽  
Author(s):  
Anton Khitrenko ◽  
Adelia Minkhatova ◽  
Vladimir Orlov ◽  
Dmitriy Kotunov ◽  
Salavat Khalilov

Abstract Western Siberia is a unique petroleum basin with exclusive geological objects. Those objects allow us to test various methods of sequence stratigraphy, systematization and evaluation approaches for reservoir characterization of deep-water sediments. Different methods have potential to decrease geological uncertainty and predict distribution and architecture of deep-water sandstone reservoir. There are many different parameters that could be achieved through analysis of clinoform complex. Trajectories of shelf break, volume of sediment supply and topography of basin influence on architecture of deep-water reservoir. Based on general principles of sequence stratigraphy, three main trajectories changes shelf break might be identified: transgression, normal regression and forced regression. And each of them has its own distinctive characteristics of deepwater reservoir. However, to properly assess the architecture of deepwater reservoir and potential of it, numerical characteristics are necessary. In our paper, previously described parameters were analyzed for identification perspective areas of Achimov formation in Western Siberia and estimation of geological uncertainty for unexplored areas. In 1996 Helland-Hansen W., Martinsen O.J. [5] described different types of shoreline trajectory. In 2002 Steel R.J., Olsen T. [11] adopted types of shoreline trajectory for identification of truncation termination. O. Catuneanu (2009) [1] summarize all information with implementation basis of sequence stratigraphy. Over the past decade, many geoscientists have used previously published researches to determine relationship between geometric structures of clinoforms and architecture of deep-water sediments and its reservoir quality. Significant amount of publications has allowed to form theoretical framework for the undersanding sedimentation process and geometrical configuration of clinoforms. However, there is still no relationship between sequence stratigraphy framework of clinoroms and reservoir quality and its uncertainty, which is necessary for new area evaluation.


2015 ◽  
Vol 11 (4) ◽  
pp. 669-685 ◽  
Author(s):  
C. Consolaro ◽  
T. L. Rasmussen ◽  
G. Panieri ◽  
J. Mienert ◽  
S. Bünz ◽  
...  

Abstract. We present results from a sediment core collected from a pockmark field on the Vestnesa Ridge (~ 80° N) in the eastern Fram Strait. This is the only deep-water gateway to the Arctic, and one of the northernmost marine gas hydrate provinces in the world. Eight 14C AMS dates reveal a detailed chronology for the last 14 ka BP. The δ 13C record measured on the benthonic foraminiferal species Cassidulina neoteretis shows two distinct intervals with negative values termed carbon isotope excursion (CIE I and CIE II, respectively). The values were as low as −4.37‰ in CIE I, correlating with the Bølling–Allerød interstadials, and as low as −3.41‰ in CIE II, correlating with the early Holocene. In the Bølling–Allerød interstadials, the planktonic foraminifera also show negative values, probably indicating secondary methane-derived authigenic precipitation affecting the foraminiferal shells. After a cleaning procedure designed to remove authigenic carbonate coatings on benthonic foraminiferal tests from this event, the 13C values are still negative (as low as −2.75‰). The CIE I and CIE II occurred during periods of ocean warming, sea-level rise and increased concentrations of methane (CH4) in the atmosphere. CIEs with similar timing have been reported from other areas in the North Atlantic, suggesting a regional event. The trigger mechanisms for such regional events remain to be determined. We speculate that sea-level rise and seabed loading due to high sediment supply in combination with increased seismic activity as a result of rapid deglaciation may have triggered the escape of significant amounts of methane to the seafloor and the water column above.


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