scholarly journals Lithology distribution model of point-bar dominated meandering river deposits for uncertainty quantification

2013 ◽  
Vol 119 (8) ◽  
pp. IX-X
Author(s):  
Takashi Tsuji ◽  
Osamu Takano ◽  
Satoko Watanabe ◽  
Kinya Okada ◽  
Koji Kashihara ◽  
...  
Geologos ◽  
2016 ◽  
Vol 22 (1) ◽  
pp. 1-14
Author(s):  
Damian Moskalewicz ◽  
Robert J. Sokołowski ◽  
Stanisław Fedorowicz

Abstract Fluvial sediments in the Chłapowo cliff section were studied in order to reconstruct their palaeoflow conditions and stratigraphical position. Lithofacies, textural and palaeohydraulic analyses as well as luminescence dating were performed so as to achieve the aim of study. Sedimentary successions were identified as a record of point bar cycles. The fluvial environment probably functioned during the latest Saalian, shortly after the retreat of the Scandinavian Ice Sheet. Discharge outflow was directed to the northwest. The river used the older fluvioglacial valley and probably was directly connected to the Eem Sea. Good preservation and strong aggradation of point-bar cycles were related to a rapid relative base level rise. The meandering river sediments recognised showed responses to climate and sea level changes as illustrated by stratigraphical, morphological and sedimentological features of the strata described. The present study also revealed several insights into proper interpretation of meandering fluvial successions, in which the most important were: specific lithofacies assemblage of GSt (St, Sp) → Sl → SFrc → Fm (SFr) and related architectural elements: channel/sandy bedforms CH/SB → lateral accretion deposits LA → floodplain fines with crevasse splays FF (CS); upward-fining grain size and decreasing content of denser heavy minerals; estimated low-energy flow regime with a mean depth of 1.6–3.3 m, a Froude number of 0.2–0.4 and a sinuosity of 1.5.


2018 ◽  
Vol 66 ◽  
pp. 189-209
Author(s):  
Aslaug C. Glad ◽  
Lars Ole Boldreel ◽  
Lars B. Clemmensen ◽  
Mads E. Willumsen

Fluvial deposits are amongst the most important terrestrial hydrocarbon reservoirs, but the complex nature of these deposits is challenging in subsurface reservoir characterisation. This study is the first detailed facies analysis of the meandering river deposits of the Middle Jurassic Alma Field situated in the southern Danish North Sea. The fluvial sandstones and their associated deposits are described and interpreted based on studies from two core sites (Alma-1X and Alma-2X). The facies analysis of the cores demonstrates the presence of three meandering river facies associations: Channel deposits, channel margin deposits and floodplain deposits. The channel deposits comprise channel thalweg and point bar sediments, the channel margin deposits include crevasse channel and crevasse splay sediments, while the floodplain deposits comprise overbank and backswamp sediments. The point bar deposits are composed of fine- to medium-grained sandstones but can contain intervals of finer grained sediments, particularly in their upper parts where they can grade into muddy sandstones or true heterolithic deposits. Preserved sand body thicknesses (channel thalweg and point bar deposits) in both Alma cores have a mean value of 2.6 m and a maximum value of 4.35 m (Alma-1X) and 6.55 m (Alma-2X). Using maximum values of channel deposit thicknesses, and assuming the preservation conditions are met, the width of the largest ancient channel belt in Alma-1X would be between 90 m and 200 m or around 900 m, depending on whether the fluvial system is mud-rich or sand-rich. The same method applied to Alma-2X gives a width of the largest channel belt between 130 m and 330 m or around 1300 m. Fluvial sediments of the Middle Jurassic Scalby Formation (north-east England) were deposited in a sandy meandering river with sedimentary characteristics corresponding to those observed in the Alma cores. Outcrop analogue investigations of this formation were carried out to examine the architecture of the fluvial facies in a two-dimensional section with emphasis on channel thalweg and point bar deposits. Combined evidence from core analysis and outcrop analogue studies suggests that the fluvial deposits in the Alma Field represent a mixed-load meandering river system with sandy point bars. The meandering river system developed on a coastal plain with overbank fines and organic-rich backswamp deposits. The mud-rich or heterolithic deposits in the upper part of the point bar facies intervals are noteworthy and could indicate markedly fluctuating discharge in a mixed-load river.


2021 ◽  
Vol 13 (1) ◽  
pp. 39-48
Author(s):  
Chao Luo ◽  
Ailin Jia ◽  
Jianlin Guo ◽  
Wei Liu ◽  
Nanxin Yin ◽  
...  

Abstract Although stochastic modeling methods can achieve multiple implementations of sedimentary microfacies model in dense well blocks, it is difficult to realize continuous convergence of well spacing. Taking the small high-sinuosity meandering river sediments of the third member of Quantou Formation in Songliao Basin as an example, a deterministic modeling method based on geological vector information was explored in this article. Quantitative geological characteristics of point bar sediments were analyzed by field outcrops, modern sediments, and dense well block anatomy. The lateral extension distance, length, and spacing parameters of the point bar were used to quantitatively characterize the thickness, dip angle, and frequency of the lateral layer. In addition, the three-dimensional architecture modeling of the point bar was carried out in the study. The established three-dimensional architecture model of well X24-1 had continuous convergence near all wells, which conformed to the geological knowledge of small high-sinuosity meandering river, and verified the reliability of this method in the process of geological modeling in dense well blocks.


2014 ◽  
Vol 50 (7) ◽  
pp. 5532-5559 ◽  
Author(s):  
E. Lotsari ◽  
M. Vaaja ◽  
C. Flener ◽  
H. Kaartinen ◽  
A. Kukko ◽  
...  

EKSPLORIUM ◽  
2017 ◽  
Vol 38 (1) ◽  
pp. 29
Author(s):  
Heri Syaeful ◽  
Adi Gunawan Muhammad

ABSTRAKKegiatan karakterisasi material bawah permukaan penyusun pondasi tapak merupakan bagian dari studi tapak instalasi nuklir. Karakterisasi dilakukan dengan berbagai metode, diantaranya pemahaman tentang sistem pengendapan formasi batuan. Sebagai bagian dari metode interpretasi lingkungan pengendapan, analisis pemodelan fasies berdasarkan elektrofasies memberikan informasi yang cepat mengenai sistem pengendapan suatu formasi batuan. Metodologi yang digunakan adalah dengan interpretrasi log sinar gamma (log GR) menggunakan korelasi relatif antara variasi bentuk log dan fasies sedimentasi. Berdasarkan analisis diketahui Formasi Bojongmanik terbentuk pada lingkungan marine-lagoonal dengan pengaruh gelombang sangat rendah. Log GR yang menunjukan bentuk funnel, bergerigi dan simetris, mengindikasikan fasies shoreface, lagoon, dan tidal point bar. Arah sedimentasi, cekungan, dan suplai pada pengendapan sedimen Formasi Bojongmanik diinterpretasikan relatif ke utara. Formasi Serpong diendapkan pada sistem sungai bermeander dan tersusun atas endapan point bar, crevasse splay dan floodplain. Hasil analisis ini diharapkan dapat menjadi panduan dalam analisis lanjutan terkait karakterisasi material pondasi. ABSTRACTThe activity of subsurface material composing site foundation characterization is part of nuclear installation siting study. Characterization conducted by several methods, such as understanding the depositional environment of rock formations. As a segment of depositional environment interpretation method, facies model analysis based on electrofacies provides quicker information on depositional system of rock formation. Methodology applied is gamma ray log (log GR) interpretation using relative correlation between log shape variation and sedimentation facies. Based on the analysis, Bojongmanik Formation was deposited on marine-lagoonal environment with very low wave influence. Log GR that shows shape of funnel, serrated, and symmetry, indicate shoreface, lagoon, and tidal point bar facies. The direction of sedimentation, basin, and supply of Bojongmanik Formation interpreted relatively to the north. Serpong Formation deposited on meandering river system, and composed of point bar deposit, crevasse splay, and floodplain deposit. The result of analysis is expected to be guidance in further analysis related to the characterization of foundation materials.


2021 ◽  
Author(s):  
ZACKERY NIETO ◽  
ALEJANDRA CASTELLANOS

Carbon fiber reinforced polymer (CFRP) composites are lightweight materials with a high stiffness-to-weight ratio and high strength-to-weight ratio. CFRP composites consist of two constituents: reinforcement and matrix. The reinforcement consists of carbon fibers and the matrix generally consists of a thermoset or thermoplastic resins. Through choices made between these two constituents, lightweight composites can be custom-tailored to fit specific criteria, including, but not limited to, water resistance for naval vessels, thermal resistance to negate environmental degradation, and UV resistance to negate UV degradation. Many uncertainties can arise with such a vast capability in adaptation depending on material choice, manufacturing methods (vacuum assisted resin transfer molding VARTM, layup, and filament winding), and post-manufacturing processes. These uncertainties can build upon one another leading to less accurate theoretical applications when compared to their real-life counterpart. The purpose of this project is to create an indepth uncertainty quantification (UQ) analysis based on vinyl-ester resin as a preliminary report for a future carbon fiber/vinyl-ester composite UQ analysis. To properly ascertain the magnitude of uncertainty during the manufacturing process, the resin to hardener ratio and cure time were studied to understand their effect on the impact response of vinyl ester samples. Vinyl ester specimens were impacted with an impact energy of 3.3 J to produce barely visible damage (BVID) on the samples. Energy, force, displacement and time were collected for analysis. Using a Monte Carlo simulation, a probability distribution model was generated to understand the effects and UQ influence of the manufacturing process in the impact response of vinyl ester specimens.


1984 ◽  
Vol 21 (1) ◽  
pp. 92-106 ◽  
Author(s):  
Samuel Y. Johnson

The Eocene Chuckanut Formation of Washington's North Cascades comprises as much as 6000 m of alluvial strata and is one of the thickest nonmarine sequences in North America. It is exposed in several disconnected outcrop belts that are remnants of what was probably an extensive fluvial system in western Washington. In this study, seven stratigraphic members are defined in the main outcrop belt of the Chuckanut Formation near the town of Bellingham. Their ages, based on fission-track zircon dates, palynologic studies, and correlation by mapping, extend from the Early to the Late Eocene.Three types of fluvial systems contributed to the Chuckanut Formation and are distinguished on the basis of their lithology, sedimentology, and petrology. The first comprises fine-load meandering-river deposits of the Lower Eocene Bellingham Bay Member and the Middle Eocene Slide Member. Sandstones are arkosic and had their main source in rapidly uplifted, high-grade metamorphic terranes in eastern Washington. The second type comprises braided- and coarse-load meandering-river deposits of the Middle to Upper Eocene Padden Member. The Padden Member occurs only in the western part of the outcrop belt and was derived form the Coast Plutonic Complex of southern British Columbia to the north. Sandstones are arkosic but are richer in lithic fragments than sandstones of the underlying Bellingham Bay Member and interfingering Slide Member. The third fluvial-system type comprises conglomerate-rich braided-river and alluvial-fan deposits of the lower Middle Eocene Governors Point Member and the Middle to Upper (?) Eocene Maple Falls, Warnick, and Bald Mountain members. Sandstones from these units are both lithic and arkosic. These strata were locally derived from uplifts on the northern basin margin.The petrology of down-basin correlatives of the Chuckanut Formation on the northeast Olympic Peninsula is incompatible with derivation through the Chuckanut fluvial system. This petrologic contrast supports a model for large-scale Eocene dextral offsets in the continental margin of Washington.


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