Depositional facies and sequence of the latest Pleistocene to Holocene incised valley fill in Kushiro Plain, Hokkaido, northern Japan

2016 ◽  
Vol 397 ◽  
pp. 159-172 ◽  
Author(s):  
Yasuhiro Takashimizu ◽  
Takashiro Shibuya ◽  
Yuichi Abe ◽  
Taku Otsuka ◽  
Shinya Suzuki ◽  
...  
2021 ◽  
Vol 11 (4) ◽  
pp. 1643-1666
Author(s):  
Ahmed M. Elatrash ◽  
Mohammad A. Abdelwahhab ◽  
Hamdalla A. Wanas ◽  
Samir I. El-Naggar ◽  
Hasan M. Elshayeb

AbstractThe quality of a hydrocarbon reservoir is strongly controlled by the depositional and diagenetic facies nature of the given rock. Therefore, building a precise geological/depositional model of the reservoir rock is critical to reducing risks while exploring for petroleum. Ultimate reservoir characterization for constructing an adequate geological model is still challenging due to the in general insufficiency of data; particularly integrating them through combined approaches. In this paper, we integrated seismic geomorphology, sequence stratigraphy, and sedimentology, to efficiently characterize the Upper Miocene, incised-valley fill, Abu Madi Formation at South Mansoura Area (Onshore Nile Delta, Egypt). Abu Madi Formation, in the study area, is a SW-NE trending reservoir fairway consisting of alternative sequences of shales and channel-fill sandstones, of the Messinian age, that were built as a result of the River Nile sediment supply upon the Messinian Salinity Crisis. Hence, it comprises a range of continental to coastal depositional facies. We utilized dataset including seismic data, complete set of well logs, and core samples. We performed seismic attribute analysis, particularly spectral decomposition, over stratal slices to outline the geometry of the incised-valley fill. Moreover, well log analysis was done to distinguish different facies and lithofacies associations, and define their paleo-depositional environments; a preceding further look was given to the well log-based sequence stratigraphic setting as well. Furthermore, mineralogical composition and post-depositional diagenesis were identified performing petrographical analysis of some thin sections adopted from the core samples. A linkage between such approaches, performed in this study, and their impact on reservoir quality determination was aimed to shed light on a successful integrated reservoir characterization, capable of giving a robust insight into the depositional facies, and the associated petroleum potential. The results show that MSC Abu Madi Formation constitutes a third-order depositional sequence of fluvial to estuarine units, infilling the Eonile-canyon, with five sedimentary facies associations; overbank mud, fluvial channel complex, estuarine mud, tidal channels, and tidal bars; trending SW-NE with a Y-shape channel geometry. The fluvial facies association (zone 1 and 3) enriches coarse-grained sandstones, deposited in subaerial setting, with significantly higher reservoir quality, acting as the best reservoir facies of the area. Although the dissolution of detrital components, mainly feldspars, enhanced a secondary porosity, improving reservoir quality of MSC Abu Madi sediments, continental fluvial channel facies represent the main fluid flow conduits, where marine influence is limited.


2016 ◽  
Vol 4 (4) ◽  
pp. T637-T655
Author(s):  
Josiah Hulsey ◽  
M. Royhan Gani

This study shows how the use of current geological investigative techniques, such as sequence stratigraphy and modern seismic interpretation methods, can potentially discover additional hydrocarbons in old fields that were previously considered depleted. Specifically, we examine the White Castle Field in South Louisiana, which has produced over 84.1 million barrels of oil and 63.1 billion cubic feet of gas but retains additional recoverable hydrocarbons. The field has pay sections ranging from late Oligocene to late Miocene. The upper Oligocene to early Miocene package, which was underexploited and understudied during the previous exploitation phase, contains three primary reservoirs (Cib Haz, MW, and MR). During most of the late Oligocene, the White Castle Salt Dome was located in a minibasin on the continental slope. The Cib Haz and MW reservoirs were deposited in this minibasin and offer great exploitation potential. The Cib Haz interval is an amalgamation of slumped shelfal limestones, sandstones, and shales interpreted to represent a lowstand systems tract (LST). The MW comprises a shelf-edge delta deposit that is also interpreted as part of a LST. The MR reservoir is interpreted as an incised valley fill located in the continental shelf that was deposited during a lowstand of sea level after the minibasin was filled. Finally, it appears that the minibasin acted as a self-contained hydrocarbon system during the late Oligocene, suggesting the possibility of a shale play. In this study, several new areas of interest are revealed that could contain economical amounts of hydrocarbons.


2018 ◽  
Vol 45 (2) ◽  
pp. 161
Author(s):  
Rodrigo M. Vega ◽  
Mauricio Mella ◽  
Sven N. Nielsen ◽  
Mario Pino

Late Pleistocene sedimentary deposits outcropping around Valdivia city, locally known as Cancagua, have been subject of contrasting interpretations, from glacial to interglacial sediments. Opposing views emerge from focusing on upstream or coastal sedimentary controls, within a zone were these potentially overlap through a full glacial cycle. Here we present the first detailed facies analysis and a broad chronological framework, reconciling previous interpretations in a single paleogeographic model that encompasses the last glacial cycle. Seven facies associations are described, interpreted as an estuarine complex developed primarily during the last glacial cycle’s highstand, yet accumulating sediments during a substantial part of the falling stage. These results offer the opportunity to extend paleoenvironmental records through a full glacial cycle in northern Patagonia.


2010 ◽  
Vol 181 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Hugues Fenies ◽  
Gilles Lericolais ◽  
Henry W. Posamentier

Abstract This paper presents a comparison between the system tract architecture and the reservoir geometries of the Gironde and Leyre (Arcachon) incised-valley fills, both located within the Bay of Biscay 100 km apart. This study, based on high resolution seismic lines acquired by Ifremer on the continental shelf and onshore core and well data, illustrates that some features of the Gironde and Leyre valleys fills are similar while some others are not. The architecture of both valley fills is characterized by fifth order depositional sequences (corresponding to an interval from 120000 yr B.P. to present day). Both valleys are filled predominantly with transgressive systems tract, with associated poorly developed lowstand and highstand systems tracts. Key stratigraphic surfaces punctuate the valley-fill architecture and comprise deeply eroding tidal ravinement surfaces merged with and enhancing, earlier formed, fluvial-related erosive sequence boundaries. These tidal ravinement surfaces can be undulatory in form and in most places mark the basal boundary of the incised valleys. In contrast, nearly horizontal wave ravinement surfaces cap the incised-valley fills, extending over the adjacent interfluves. The Gironde and Leyre (Arcachon) valley fills exhibit two main stratigraphic differences: 1) transgressive systems tract sand bodies are ribbon shaped within the Gironde and tabular shaped within the Leyre; 2) lowstand systems tract deposits, represented by fluvial sediments, are preserved within the Gironde but absent within the Leyre. In a wave- and tide-dominated environment, the geometry of the sandbodies within the transgressive systems tract is a function of the tidal ravinement processes, which characterizes the estuary inlet. Two categories of tidal ravinement processes can be distinguished here: “anchored tidal ravinement” and “sweeping tidal ravinement”. The Gironde estuary is characterized by an “anchored tidal ravinement”. The tidal inlet has remained largely in a fixed location; littoral drift has not shifted the tidal inlet to the south because it is constrained by resistive Eocene carbonates that define the margins of the Gironde incised valley. In contrast, the Leyre estuary is characterized by a “sweeping tidal ravinement”. The inlet has been shifted approximately 30 km to the south by the formation of a littoral drift associated spit. This extensive lateral shifting was made possible by the fact that the incised valley was cut into unconsolidated, easily eroded Pleistocene sands. Within a wave- and tide-dominated environment, the preservation potential of the lowstand systems tract is a function of the size of the fluvial drainage basin. During lowstand time, the erosive power of the fluvial discharge was much greater within the much larger Gironde valley, consequently the fluvial sequence boundary was cut much deeper in the Gironde valley than within the Leyre valley and, correspondingly, the thickness of the associated fluvial deposits was commensurately greater. In response, the lowstand systems tract was not preserved within the Leyre valley fill because the depth of tidal ravinement erosion formed during the sea-level rise and associated transgression was greater than that associated with fluvial incision generated during the sea-level fall.


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