scholarly journals A Conversion for Average Grain Size Based on Gamma Ray Well Log: Application in the Second Member of Xujiahe Formation of Anyue Area, Sichuan Basin

2021 ◽  
Vol 9 ◽  
Author(s):  
Liang Chen ◽  
Hancheng Ji ◽  
Nansheng Qiu ◽  
Liang Zhang
Keyword(s):  
Grain Size ◽  
Sichuan Basin ◽  
Gamma Ray ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Xujiahe Formation ◽  
Average Grain Size ◽  
Logarithmic Relationship ◽  
Clastic Reservoirs

The grain sizes of clastic rock sediments serve as important depositional indicators that are significant in sedimentology and petroleum geology studies. Generally, gamma ray, spontaneous-potential and resistivity well logs are utilized to qualitatively characterize variations in sediment grain size and determine the lithology in clastic reservoirs. However, grain size analysis of modern sedimentary samples collected from active rivers and deltas indicates that the percentage of fine depositional component has a logarithmic relationship with the average grain size in delta and river systems. Using the linear relationship to process the lithology interpretation, siltstones or mudstone is likely to be interpreted as sandstone. Therefore, a logarithmic conversion formula was built up between the gamma ray logs and measured grain size for the second member of the Xujiahe Formation of Anyue Area in the Sichuan Basin. Using the formula, the average grain size and lithology of the exploration wells were determined for the interest intervals. Furthermore, the calculated grain size gives a better understanding of the controlling factors of hydrocarbon-bearing reservoirs in the study area.

scholarly journals Centennial Impacts of the East Asian Summer Monsoon on Holocene Deltaic Evolution of the Huanghe River, China

2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi
Keyword(s):  
Grain Size ◽  
Yellow River ◽  
Asian Summer Monsoon ◽  
River Delta ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Huanghe River ◽  
Huanghe River Delta ◽  
The Huanghe River

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.

SEDIMENT GRAIN SIZE ANALYSIS IN LONG ISLAND MARSH CORES

2020 ◽  
Author(s):  
Faith A. Renner ◽  
◽  
E. Christa Farmer ◽  
Moread Achek ◽  
Brandon Buchbinder ◽  
...  
Keyword(s):  
Grain Size ◽  
Long Island ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size

scholarly journals On the digitalization of the parameters of native gold particles in the study of placers and concentrate and mineralogical studies

2021 ◽  
pp. 60-72
Author(s):  
BARANNIKOV Aleksandr Grigor’evich ◽  
Keyword(s):  
Grain Size ◽  
Native Gold ◽  
Digital Data ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Important Indicator ◽  
Gold Particles ◽  
Rigorous Approach ◽  
Average Grain Size ◽  
Average Size

Relevance of the work is due to the need to increase the efficiency of studying the particles of native gold in placers using morphometric (morphogranulometric) parameters in their documentation. Graphic materials (maps, plans, sections) based on digitalization of the collected data help to increase the reliability of the forecast, make it possible to use the selected areolas in combination with other methods when assessing ore-bearing zones and areas. Purpose of the work: development of a systematics of native gold identification on a morphometric basis. Substantiation on the basis of digital data of placer samples indicators – form of gold grains, average grain size, hydraulic particle size; study of the spatial variability of the revealed parameters of the metal within the rebuilt placers. Research methodology: diagnostics (description) of the morphology of gold grains and other typomorphic features based on the quantitative parameters of particles with the subsequent calculation of the shape coefficients (flatness, elongation); generalization and interpretation of the results of the description of native gold previously obtained during the exploration of the Ural placers. Results. The proposed systematics of native gold outwards on a morphometric basis allows a more rigorous approach to the identification of metal particles (excluding the subjectivity of describing the outward look of ore). When substantiating the average size of gold grains, significant discrepancies were noted in the results obtained by two independent methods: when measuring the parameters of gold grains on a morphogranulometric basis and using traditional sieve grain size analysis. The geological factors that determine the level of discrepancy between the compared methods are considered. It is about how the revealed discrepancies should be taken into account in the practice of forecasting and prospecting works. It is argued that the most important indicator characterizing the migratory mobility of gold particles in an aquatic environment is their hydraulic size (HS, cm/s). An approach to substantiating HS based on measurements of morphogranulometric parameters of particles (axes A, B, C) is proposed. Examples are considered based on the interpretation of the accumulated digital data in the mineralogical mapping of a number of ore-bearing areas and sites. Conclusions. Long years of studying native gold from placers using the developed systematics of particles on a digital (morphogranulometric) basis have been tested by the practice of forecasting and prospecting and research works. The described approach, based on digitalization of the accumulated information, is recommended for implementation and further improvement

scholarly journals Sedimentary Environment Analysis by Grain-Size Data Based on Mini Batch K-Means Algorithm

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qiao Su ◽  
Yanhui Zhu ◽  
Yalin Jia ◽  
Ping Li ◽  
Fang Hu ◽  
...  
Keyword(s):  
Grain Size ◽  
Network Model ◽  
Subjective Experience ◽  
Sedimentary Environment ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Bipartite Network ◽  
Size Category ◽  
Sediment Grain Size ◽  
Environment Analysis

During the last several decades, researchers have made significant advances in sedimentary environment interpretation of grain-size analysis, but these improvements have often depended on the subjective experience of the researcher and were usually combined with other methods. Currently, researchers have been using a larger number of data mining and knowledge discovering methods to explore the potential relationships in sediment grain-size analysis. In this paper, we will apply bipartite graph theory to construct a Sample/Grain-Size network model and then construct a Sample network model projected from this bipartite network. Furthermore, we will use the Mini Batch K-means algorithm with the most appropriate parameters (reassignment ratio ϵ=0.025 and mini batch = 25) to cluster the sediment samples. We will use four representative evaluation indices to verify the precision of the clustering result. Simulation results demonstrate that this algorithm can divide the Sample network into three sedimentary categorical clusters: marine, fluvial, and lacustrine. According to the results of previous studies obtained from a variety of indices, the precision of experimental results about sediment grain-size category is up to 0.92254367, a fact which shows that this method of analyzing sedimentary environment by grain size is extremely effective and accurate.

A reconstruction of late Pleistocene relative sea level in the south Bohai Sea, China, based on sediment grain-size analysis

2012 ◽  
Vol 281 ◽  
pp. 88-100 ◽  
Author(s):  
Liang Yi ◽  
Hongjun Yu ◽  
Joseph D. Ortiz ◽  
Xingyong Xu ◽  
Xiaoke Qiang ◽  
...  
Keyword(s):  
Grain Size ◽  
Sea Level ◽  
Late Pleistocene ◽  
Bohai Sea ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
The South ◽  
Relative Sea Level ◽  
Sediment Grain Size

scholarly journals SEBARAN PASIR LAUT SEBAGAI BAHAN GALIAN DI LEPAS PANTAI SELAT RIAU

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Deny Setiady ◽  
Udaya Kamiludin ◽  
Ildrem Syafri
Keyword(s):  
Grain Size ◽  
Silty Sand ◽  
Coastal Sediments ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sand Beach ◽  
Sediment Grain Size ◽  
Offshore Area ◽  
Sandy Gravel ◽  
Sandy Silt

Daerah penelitian terletak di perairan antara Pulau Batam dan Pulau Bintan (Selat Riau), termasuk ke dalam wilayah Kotamadya Batam dan Kabupaten Bintan, Provinsi Kepulauan Riau. Metode penelitian yang dilakukan adalah pengambilan posisi (navigasi), pengukuran kedalaman dasar laut, pengamatan dan pengambilan contoh sedimen pantai, pengambilan contoh sedimen dasar laut, serta analisis laboratorium. Tujuan penelitian adalah untuk mengetahui sebaran pasir pasir laut, serta ketebalannya berdasarkan karakteristik ukuran butirannya, agar potensi bahan galian tersebut dapat diketahui. Berdasarkan analisis ukuran butir sedimen di pantai Pulau Batam dan Pulau Bintan diketahui berukuran pasir, kerikil pasiran, pasir kerikilan dan lanau pasiran, sedangkan sebaran sedimen dasar laut terdiri dari: kerikil pasiran, pasir kerikilan, pasir, pasir lanauan dan lanau pasiran. Kedalaman sedimen pasir di pantai Pulau Batam antara 1 meter sampai 2,6 meter, sedangkan ketebalan sedimen pasir di Pulau Bintan antara 0,6 meter sampai 2 meter. Kata Kunci: sedimen, ukuran butir, pasir, bahan galian, Selat RiauThe study area is located in offshore area between Batam and Bintan Islands (Riau Strait), including of Batam and Bintan regency, Kepulauan Riau Province. The research methods carried out were position taking (navigation), depth of seabed measurement (bathymetry), observation and coastal sediments sampling, seabed sediments sampling, and laboratory analysis. The objectives of the study is to know the sand beach and sea sand distribution and its thickness based on characteristics of grain size, as well as to know those construction materials. Based on sediment grain size analysis on the Batam and Bintan islands, sand beach consists of: sand, sandy gravel, gravelly sand and sandy silt, while seafloor surficial sediments distribution consist of sandy gravel, gravelly sand, sand, silty sand and sandy silt. The depth of sand sediment on Batam beach is between 1 to 2.6 meters, while the depth of sand sediment in Bintan Island coastal is between 0.6 meters to 2 meters. Keywords: sediment, grain size, sands, substrate material, Riau Strait

scholarly journals JENIS DAN SEBARAN SEDIMEN DI PERAIRAN PAPELA DAN SEKITARNYA, ROTE-NDAO, NUSA TENGGARA TIMUR

2016 ◽  
Vol 13 (3) ◽  
pp. 153
Author(s):  
Deny Setiady ◽  
Udaya Kamiludin ◽  
Nienu Yayu Gerhaneu
Keyword(s):  
Grain Size ◽  
Water Area ◽  
Silty Sand ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
The North ◽  
Sandy Silt ◽  
Seafloor Sediments

Daerah Penelitian terletak di perairan Papela dan sekitarnya yang merupakan bagian dari Selat Rote yang secara administratif merupakan wilayah dari Kabupaten Rote-Ndao, Provinsi Nusa Tenggara Timur. Di daerah penelitian pada 40 lokasi telah dilakukan pengambilan sedimen dasar laut dengan pemercontoh comot, deskripsi megaskopis dan analisis besar butir. Penelitian bertujuan untuk mengetahui jenis sedimen, sebaran sedimen dan lingkungan pengendapannya. Berdasarkan hasil analisis besar butir nomenklatur sedimen di daerah penelitian dijumpai 4 jenis sedimen yaitu: kerikil, pasir, pasir lanauan, lanau pasiran dan lanau. Sebaran kerikil terdapat di dua tempat, yaitu di utara dan selatan tepian daerah penelitian.Sebaran pasir mencapai kurang lebih 30 % dari luas perairan penelitian, pasir lanauan menutupi kurang 5 % dari luas perairan penelitian, lanau pasiran mempunyai sebaran kurang lebih 30 % dari luas perairan daerah penelitian dan sebaran lanau terdapat di muka muara sungai bagian dalam Teluk Papela dengan tutupan kurang lebih 5 % dari luas perairan penelitian.Kata kunci Sedimen permukaan dasar laut, analisis besar butir, sebaran sedimen, perairan Papela The study area is located in Papela waters area and that is part of the Rote Strait, administratively is a region of Rote-Ndao regency, East Nusa Tenggara Province. The method of research conducted is sampling seafloor sediments, megaskopis description and analysis of the grain size. The study area is located in Papela waters area and that is part of the Rote Strait, administratively is a region of Rote-Ndao regency, East Nusa Tenggara Province. The method of research conducted is sampling seafloor sediments, megaskopis description and analysis of the grain size. The purpose of research is the grain size analysis of seabed surface sediment to determine the type of sediment, sediment distribution and depositional environment. Based on nomenklature sediment grain size analysis result in the study area was found four types of sediments , there are: gravelly, sand, silty sand, sandy silt and silt Distribution of gravel found in two places, namely on the north and south banks of the study area. Distribution of sand reaches approximately 30% of the water area of research, silty sand covering approximately 5% of the water area of research, sandy silt has spread approximately 30% of the total water area of research and distribution of silt contained in the inner face of the Gulf estuaries Papela with cover approximately 5% of the water area of research. Keywords: Surficial sediment, grain size analysis, sediment distribution, Papela Waters

scholarly journals Micro structural control of stabilized Zirconia ceramics (8YSZ) through modified conventional sintering methodologies

2010 ◽  
Vol 42 (1) ◽  
pp. 91-97 ◽  
Author(s):  
K. Rajeswari ◽  
Rajasekhar Reddy ◽  
U.S. Hareesh ◽  
B.P. Saha ◽  
R. Johnson
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Structural Control ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Stabilized Zirconia ◽  
Average Grain Size ◽  
Conventional Sintering ◽  
Slip Cast ◽  
Rate Controlled

Slip cast Y2O3 stabilized Zirconia (8YSZ) ceramics was subjected to Conventional Ramp and Hold (CRH), Rate Controlled (RCS) and Two Stage Sintering (2SS) methodologies. Sintered samples were characterized for their densities and grain size analysis by Scanning Electron Microscopy. The slip cast samples sintered by CRH and 2SS have achieved 98 - 99 % of theoretical densities while RCS samples have exhibited a low density of 97 %. The samples exhibited an average grain size of 2.64 ?m by 2SS sintering in comparison to 8.83 ?m in case of CRH and 3.45 ?m in case of RCS. Controlled pore growth associated with RCS, when compared to CRH methodology is mainly responsible for the relatively smaller grain size observed with RCS. A four fold decrease in grain size i.e. 2.64 ?m observed with the two step sintering can be attributed to the fact that the first heating step to high temperature of 1550?C for a shorter duration closes the porosity without significant grain growth. The second step at 1375?C for a longer period of time imparts densification with limited grain growth.

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