Delta Front Depositional System Study Based on Seismic Attributes and Well Logging Facies

2012 ◽  
Vol 170-173 ◽  
pp. 1285-1289 ◽  
Author(s):  
Xu Tao Li ◽  
Chang Song Lin

Along with analysis of logging facies characteristics of drilled wells, isometric strata slicing technique for seismic attribute is applied to interpret the distribution of the depositional systems in the study area. It is understood that Nenjiang3 Formation in Xinbei area of Xinli field consists of water regressive and sand progressive delta front depositional system from bottom to top. Combined with analogue analysis of well logging facies and planar seismic attributes, it is learned that sediments generally came from the north area, and main sedimentary microfacies include underwater distributary channels, river mouth bars, sheet sands body and interdistributary bays of delta front. With isometric slicing for the extraction of seismic attributes and logging operation, the distribution rules for sedimentary systems could analyzed, thereby providing a feasible method that could be referenced by the study on sedimentary system distribution of other areas.

2012 ◽  
Vol 616-618 ◽  
pp. 48-51
Author(s):  
Huan Jun Jia

By applying the data of drilling core, well logging and 3D seismics and studying the sequence framework, sedimentary microfacies and shallow gas distribution law, it shows that the Heidimiao Reservoir is vertically divided into a long-term, 4 intermediate-term and 25 short-term base-level cycles. Heidimiao Reservoir is of the gentle river controlled sedimentary system of delta front The main microfacies are underwater distributary channels, mouth bars and distal bars. Shallow gas is vertically distributed in the reservoir sandbody at the period of intermidiate hemicycles of late decrease or early rise in long-term hemicycles of the early fall. It is reasonable match of distribution discipline of single sandbody, gas source faults and structure that is the dominated factor for shallow gas plane accumulation. Based on the study above, 90 gas traps are depicted by applying the gas-water interpretation templates.


Author(s):  
S. Vyzhva ◽  
I. Solovyov ◽  
I. Mihalevich ◽  
V. Kruhlyk ◽  
G. Lisny

Based on the results of numerous seismic surveys conducted on the areas and deposits of the northern side of the Dnieper-Donetsk depression, an appropriate strategy for detecting hydrocarbon traps in this region has been determined. This takes into account modern requirements for exploration and prospecting of gas and oil deposits. They consist in determining the probable zones of accumulation of hydrocarbons based on the analysis of the structural-tectonic model. At the same time, the use of direct hydrocarbon indicators to predict structural, lithological or combined traps is also a necessary element in solving this problem. It has been shown that an effective approach to detecting hydrocarbon traps in this region is attribute analysis using seismic attributes such as seismic signal envelope, acoustic impedance or relative acoustic impedance. In most practically important cases, the analysis of the distribution of values of these attributes was sufficient to solve geological problems. At the same time, an example of extracting additional useful information on the spatial distribution of hydrocarbon traps from volumetric seismic images obtained from seismograms of common sources with a limited range of seismic angle inclinations is given. To analyze the distributions of seismic attribute values it is recommended to use geobody technology as the most effective one when using volumetric seismic data. Depending on the combination of seismic attributes involved in the analysis, the distributions of different properties of rocks are determined, in particular the zone of increased porosity or the presence of hydrocarbons. Analysis with the simultaneous use of several seismic attributes allows to directly identify hydrocarbon-rich geological bodies with high porosity and the like. The paper presents examples of detection of hydrocarbon traps in the areas and deposits of the northern side of the Dnieper-Donetsk depression, which are confirmed by drilled wells. An example of providing recommendations for wells drilling using the distributions of values of different seismic attributes is given. Generalizations are made on the distribution of promising areas for the presence of hydrocarbons on the northern side of the Dnieper-Donetsk depression and the ratio of this distribution with the identified structural elements of the geological environment.


2020 ◽  
Author(s):  
Dong-Geun Yoo ◽  
Seok-Hwi Hong ◽  
Gwang-Soo Lee ◽  
Jin-Cheul Kim ◽  
Gil-Young Kim ◽  
...  

<p>Sequence analysis using borehole samples and high-resolution seismic data in the Nakdong River valley reveals that the Nakdong River valley deposits, approximately 60 - 70 m thick, consist of a set of lowstand, transgressive, and highstand systems tracts that corresponds to a fifth-order (20 ka) sea-level cycle. Four main depositional systems, including ten sedimentary facies, constitute these systems tracts: fluvial, estuary, coastal/shoreface, and delta. The lowstand systems tract (LST), consisting of gravelly sand, forms a fluvial depositional system (Unit I) which fills the thalweg of river valley mainly developed approximately before 12 ka. The transgressive systems tract (TST) can be divided into two depositional systems (Unit II and III). The river-derived sediments were trapped within the paleo-estuary, forming an estuarine depositional system (Unit II) developed between 12 and 6 ka. As the transgression continued, the coarse sediments were deposited and redistributed by coastal processes, resulting in coastal/shoreface depositional system (Unit III). It is characterized by an isolated sand body and thin sand veneer. The HST is composed of deltaic depositional system including delta plain, delta front, and prodelta (Unit IV). During the delta progradation, most coarse-grained sands derived from the river were deposited in the lower delta plain and delta front, forming sand bars and shoals less than 15 m deep. The remaining fine-grained sediments were transported further offshore in a suspension mode and deposited in the inner shelf off the present river mouth, forming a subaqueous prodelta. Radiocarbon and optica<strong>lly stimulated luminescence (OSL</strong>) dating suggest that the recent deltaic system was initiated by aggradational and progradational stacking patterns at approximately 8 ka during the last stage of decelerated sea-level rise, and was then followed by a prograding clinoform after the highest sea level at approximately 6 ka.</p>


2020 ◽  
Vol 8 (2) ◽  
pp. SJ17-SJ34 ◽  
Author(s):  
Shuvajit Bhattacharya ◽  
Sumit Verma

Exploration of the Brookian sandstone reservoirs in the Nanushuk and Torok Formations on the North Slope of Alaska is a hot topic and presents opportunities to the oil and gas community because of their shallow depth, vast extent, and scope of development. The consecutive hydrocarbon discoveries announced by Repsol-Armstrong, Caelus Energy, and ConocoPhillips in 2015, 2016, and 2017 have indicated the presence of the vast recoverable resources on the North Slope in the Nanushuk and Torok reservoirs. We have investigated the detailed geophysical and petrophysical characteristics of these reservoirs. Our goal is to detect dominant geologic features in these formations using a combination of seismic attributes at the regional scale and analyze critical petrophysical and rock physics properties to evaluate formation heterogeneities and identify the reservoir targets by integrating well log and core data at the well scale. The Nanushuk Formation is expressed as topset reflections, whereas the Torok and gamma-ray zone formations are expressed as foresets and bottomsets on the seismic reflection data. Using seismic attributes, we mapped the extent of different geomorphological features, including shelf edges, channels, slides, and basin-floor fans, all with significant amplitude anomalies. The shelf edges continue for tens to hundreds of miles along the north/northwest and east–west directions, depending on the areas. The internal characters of these formations delineated by conventional well logs and advanced petrophysical analysis reveal their vertical heterogeneities and complexities, in terms of reservoir properties. We conclude that the reservoirs are vertically and laterally heterogeneous. These are thin-bedded low-resistivity reservoirs. Only a few zones in the parasequences are oil-saturated. We find that a combination of low [Formula: see text] ratio and acoustic impedance can be a useful proxy to detect the hydrocarbon-bearing sand intervals in these formations.


1993 ◽  
Vol 27 (7-8) ◽  
pp. 381-385 ◽  
Author(s):  
Y. Oziransky ◽  
B. Shteinman

Data of high spatial and temporal resolution, and a special sampling program are essential for successful application of mathematical models designed to reproduce observed seasonal patterns of temperature, dissolved oxygen, nutrients, pH, and algal biomass for both vertical and longitudinal gradients in a water body. Lake Kinneret suspended solids are of great potential value for estimating transport, exposure to water body elements, and fate of many toxic substances. Therefore the distribution of admixtures in two longitudinal and five vertical segmentation schemes were examined with the two-dimensional water body quality box model “BETTER” (Bender et al, 1990). The transects were taken in the north-western part of Lake Kinneret close to the Jordan River mouth and the National Water Carrier (NWC) head pumping station. The outflow volumes were given according to regular sampling of natural speed of water outflow from different lake layers under calm conditions. Temporal distribution of mixing concentrations as well as turbulent diffusion horizontal coefficients due to the spatial distribution of turbulent scale were obtained during the model's run with the December 1991 data.


2020 ◽  
Vol 95 ◽  
pp. 84-96
Author(s):  
Gang Xu ◽  
Jian Liu ◽  
Marcello Gugliotta ◽  
Yoshiki Saito ◽  
Lilei Chen ◽  
...  

AbstractThis paper presents geochemical and grain-size records since the early Holocene in core ECS0702 with a fine chronology frame obtained from the Yangtze River subaqueous delta front. Since ~9500 cal yr BP, the proxy records of chemical weathering from the Yangtze River basin generally exhibit a Holocene optimum in the early Holocene, a weak East Asian summer monsoon (EASM) period during the middle Holocene, and a relatively strong EASM period in the late Holocene. The ~8.2 and ~4.4 cal ka BP cooling events are recorded in core ECS0702. The flooding events reconstructed by the grain-size parameters since the early Holocene suggest that the floods mainly occurred during strong EASM periods and the Yangtze River mouth sandbar caused by the floods mainly formed in the early and late Holocene. The Yangtze River-mouth sandbars since the early Holocene shifted from north to south, affected by tidal currents and the Coriolis force, and more importantly, controlled by the EASM. Our results are of great significance for enriching both the record of Holocene climate change in the Yangtze River basin and knowledge about the formation and evolution progress of the deltas located in monsoon regions.


2015 ◽  
Vol 3 (1) ◽  
pp. SB5-SB15 ◽  
Author(s):  
Kurt J. Marfurt ◽  
Tiago M. Alves

Seismic attributes are routinely used to accelerate and quantify the interpretation of tectonic features in 3D seismic data. Coherence (or variance) cubes delineate the edges of megablocks and faulted strata, curvature delineates folds and flexures, while spectral components delineate lateral changes in thickness and lithology. Seismic attributes are at their best in extracting subtle and easy to overlook features on high-quality seismic data. However, seismic attributes can also exacerbate otherwise subtle effects such as acquisition footprint and velocity pull-up/push-down, as well as small processing and velocity errors in seismic imaging. As a result, the chance that an interpreter will suffer a pitfall is inversely proportional to his or her experience. Interpreters with a history of making conventional maps from vertical seismic sections will have previously encountered problems associated with acquisition, processing, and imaging. Because they know that attributes are a direct measure of the seismic amplitude data, they are not surprised that such attributes “accurately” represent these familiar errors. Less experienced interpreters may encounter these errors for the first time. Regardless of their level of experience, all interpreters are faced with increasingly larger seismic data volumes in which seismic attributes become valuable tools that aid in mapping and communicating geologic features of interest to their colleagues. In terms of attributes, structural pitfalls fall into two general categories: false structures due to seismic noise and processing errors including velocity pull-up/push-down due to lateral variations in the overburden and errors made in attribute computation by not accounting for structural dip. We evaluate these errors using 3D data volumes and find areas where present-day attributes do not provide the images we want.


2021 ◽  
Vol 2 (1) ◽  
pp. 6.1-6.16
Author(s):  
Natalie Robertson

This article considers how Indigenous stories and chants can tell us about our ecologies in the time of environmental emergencies. For Ngāti Porou of the lower reaches of the Waiapu river catchment in Te Ika-a-Māui, the North Island of Aotearoa (New Zealand), the slow catastrophes of twentieth-century colonial deforestation impacts, introduced pest-induced inland forest collapse and predicted twenty-first-century climate change sea level rise have converged as our most pressing environmental problems. Waiapu is home to Ngāti Porou Tūturu, coastal fishing people who value their relationships with fish species, notably kahawai. The mōteatea chant form acts as a guide to my photographic and moving image practice to visualize and voice the slow catastrophe of the river. In this article, I discuss how the Ngāti Porou mōteatea He Tangi mo Pāhoe, which reveals nineteenth-century ecological knowledge, particularly of fish species, is reimagined as a moving image visual mōteatea. Through reframing the threats as the current faces of our ancestors, this article proposes a shift in thinking from vulnerability into resilience.


2019 ◽  
Vol 18 (3) ◽  
pp. 62-73
Author(s):  
A. N. Chekha

Purpose. There are many archaeological sites located in the North Angara region. Although this territory has been investigated since 18th century, most intensive work was done during rescue archaeological works on Boguchany hydroelectric power station in 2008–2011. One of the valuable sources of artifacts is the Kutarey site. Our work contains a brief analysis of stone industries of the Kutarey River Mouth site. The main goal of this work is to apply technical and typological analysis to mark the specificity of the stone industries of layer 2 of the Kutarey River Mouth site in comparison with the results that had been previously published on layer 3 in the context of new data of this region in terms of ceramics complexes. We introduce a previously unpublished collection of stone artifacts of layer 2 of the Kutarey River Mouth site, which significantly extends the source base of the Neolithic and Bronze Age in this region. Results. The Kutarey River Mouth site is located on the left bank of the Angara River, 15 km down from the Kezhma village, on the right bank of the Kutarey River. The location was found in 1974 by N. I. Drozdov and his squad. The site was further investigated in 2008 and in 2010 by an IAE SB RAS squad (guided by A. N. Savin). Firstly, the site was determined as a Neolithic location, but as result of 2010 excavations three Neolithic-Middle Age cultural horizons were discovered. In the context of the difficulties connected with conducting investigations in this region, namely an open location, a low stratigraphy situation, a high extend of technogenic interruption, the materials of layer 3 are most perspective due to a high grade of saturation of the artifacts and minimal technogenic interruptions. These materials belong to the Neolithic and Paleometal Era. In order to clarify cultural and chronological specificity of this complex, it is necessary to analyze materials from layer 2. The stone industry of layer 2 is represented by retouching microblades, bladelets, tools for blades, flakes, scrapers including one microscraper, bifaces, several adzes, axes, and one piercing tool. Of special interest are blade points and trihedral and tetrahedral points. Conclusion. Our technical and typological analyses show that in comparison to layer 3, layer 2 is characterized by a small number of massive axes and adzes, no flints, few double scrapers, and only volume splitting tools aimed mainly at obtaining a small blade. Also, despite the fact that the core of the collection is the product of the hornstones of local origin, we observe a significant increase in the percentage of artifacts made of flint (13 %), which may indicate some new commodity strategies. The most interesting analogy can be traced with the dedicated Upper Kolyma Early Holocene complex, which contained blade points widely distributed in Northeast Asia and was present directly or indirectly in the materials from Chukotka (Verkhnetirsky IV and Nizhnechutinsky IV), Yakutia (Olbinski burial ground, Jubilee), Kamchatka (the Ushki I–IV layer, Avacha 1,9). This complex is believed to belong to specific Volbinsky traditions, which formed in the first half of the Holocene, about 8800–6000 years ago. It is also worth comparing these materials with other Kutarey sites – Sen’kin (Siniy) Kamen’, Ruchei Povarny, Gora Kutarey and adjacent territories.


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