scholarly journals Organic Geochemical Characteristics of Mudstone and Marl from Western Hoh Xil Basin of Tibet

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wentian Mi ◽  
Xueyuan Qi ◽  
Yan Shang ◽  
Xu Kong ◽  
Zifu Hu
Keyword(s):  
Organic Matter ◽  
Higher Plants ◽  
Organic Geochemistry ◽  
Sedimentary Environment ◽  
Sedimentary Facies ◽  
Alluvial Fan ◽  
Maturity Stage ◽  
Type I ◽  
High Productivity ◽  
Sedimentary Characteristics

The mudstone and marl from western Hoh Xil basin, located in Tibet of the west of China, were deposited in Tertiary lacustrine environment. Investigation of organic geochemistry, sedimentary characteristics, and 13C in kerogen was conducted to analyze the sedimentary environment, biomarkers, paleoclimate, and source of organic matter during deposition. The Cenozoic sedimentary facies of the basin included upper lacustrine facies and lower alluvial fan facies, which belong to Miocene Wudaoliang Formation and Oligocene Yaxicuo Group, respectively. The Miocene marl-sandstone-mudstone from Wudaoliang Formation was analyzed. Maceral composition was dominated by amorphous organic matter. T max values indicated that the mudstones were thermally immature-low maturity with mainly type II and III organic matter, while organic matter in marlite belongs mainly to type I-II1 with low maturity-maturity stage. The biomarkers showed the characteristics of odd-over-even predominance of long-chain n-alkanes, higher proportion of C27 sterane in most of the samples, heavy δ13Corg composition, low Pr/Ph ratios (0.11-0.36), and so on. Organic geochemistry indicated that the organic matter originated from bacteria, algae, and higher plants. The rocks were formed in reducing environments with stratified water column and high productivity. The paleoclimate became more humid during depositional stage in the western Hoh Xil basin.

scholarly journals Petrography and Organic Geochemistry Characterizations of Lower Paleozoic Organic-Rich Shale in the Northwestern Upper Yangtze Plate: Niutitang Formation and Longmaxi Formation, Dabashan Foreland Belt

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 439 ◽  
Author(s):  
Delu Li ◽  
Rongxi Li ◽  
Di Zhao ◽  
Feng Xu
Keyword(s):  
Gas Chromatography ◽  
Organic Matter ◽  
Organic Geochemistry ◽  
Source Rocks ◽  
Gas Chromatography Mass Spectrometry ◽  
Mature Stage ◽  
Type I ◽  
Lower Paleozoic ◽  
Longmaxi Formation ◽  
Niutitang Formation

Measurements of total organic carbon, Rock-Eval pyrolysis, X-ray diffraction, scanning electron microscope, maceral examination, gas chromatography, and gas chromatography-mass spectrometry were conducted on the organic-rich shale of Lower Paleozoic Niutitang Formation and Longmaxi Formation in Dabashan foreland belt to discuss the organic matter characteristic, organic matter origin, redox condition, and salinity. The results indicate that the Niutiang Formation and Longmaxi Formation organic-rich shale are good and very good source rocks with Type I kerogen. Both of the shales have reached mature stage for generating gas. Biomarker analyses indicate that the organic matter origin of Niutitang Formation and Longmaxi Formation organic-rich shale are all derived from the lower bacteria and algae, and the organic matter are all suffered different biodegradation degrees. During Niutitang Formation and Longmaxi Formation period, the redox conditions are both anoxic with no stratification and the sedimentary water is normal marine water.

Sedimentary Characteristics and Reservoir Potential of Underwater Alluvial Fan

2014 ◽  
Vol 912-914 ◽  
pp. 1525-1528
Author(s):  
Wei Fu Liu ◽  
Shuang Long Liu ◽  
Li Xin Sun
Keyword(s):  
Sedimentary Facies ◽  
Body Part ◽  
Alluvial Fan ◽  
Sedimentary Characteristics ◽  
Gravitational Flow ◽  
Braided Channel ◽  
Density Flow ◽  
Sedimentary Microfacies ◽  
Braided Structure ◽  
Reservoir Potential

Using core analysis, thin slice identification, logging analysis and seismic interpretation, systemic study upon sedimentary types, sedimentary facies, physical and oil bearing properties of each sedimentary microfacies, etc presenting in underwater alluvial fan of Kerqin oilfield of Kailu basin in China, is performed. To identify sedimentary characteristics of underwater alluvial fan and determine its oil bearing property so as to develop this type of reservoir reasonably and effectively. Underwater alluvial fan comprises of 5 kinds sedimentary facies: clastic flow, high density flow, low density flow, overflow and river channel sedimentation. Further division includes three sub-facies, i. e. tail, body and front part of underwater alluvial fan, among which braided structure of body part features favorable accumulation and oil bearing properties. Underwater alluvial fan is formed from the double action mechanisms of gravitational flow and traction flow. Body microfacies are primary oil bearing play and braided channel is the main future development target.

COMPARISON OF SELECTED NON-MARINE PETROLEUM-BEARING BASINS IN AUSTRALIA AND CHINA

1986 ◽  
Vol 26 (1) ◽  
pp. 285
Author(s):  
P.S. Moore D.K. Hobday H. Mai ◽  
Z.C. Sun
Keyword(s):  
Ordos Basin ◽  
Sedimentary Facies ◽  
Alluvial Fan ◽  
Source Rocks ◽  
Local Source ◽  
Type I ◽  
Migration Routes ◽  
Factors Affecting ◽  
Half Graben ◽  
Oil Source

This paper summarises the geology and hydrocarbon potential of two Chinese and two Australian basins (Ordos, Northern Jiangsu, Eromanga, and Surat basins) in order to compare factors affecting the generation, migration, and entrapment of hydrocarbons. In all four basins, hydrocarbons are generated from nonmarine source rocks of lacustrine and fluvial-overbank origin. While the Chinese and Australian basins contain a similar range of sedimentary facies, from alluvial fan to lacustrine, the arrangement and relative thicknesses of these facies vary considerably as a result of different tectonic and palaeoclimatic settings.During the Triassic, the Ordos Basin was dominated by retroarc foredeep subsidence and the development of deep, fresh-water lakes with anoxic bottom waters. This non-bioturbated substrate, with Type I and II kerogen precursors, provided an excellent oil source for adjacent fan-delta, deltaic, and fluvial reservoirs, and for the unconformably overlying Jurassic fluvial valley-fill sandstone reservoirs.The Northern Jiangsu Basin was initiated by back-arc extension and underwent very rapid half-graben subsidence in the Eocene. Alluvial fan, shoreline, and fluvial facies aggraded in a relatively narrow zone along the active, faulted margin, and merged laterally into organic-rich shales which provided a local source for oil.By comparison, the Eromanga/Surat basins developed in response to gentle downwarp and reactivation of older structural trends. Reservoirs are largely restricted to craton-derived quartzose facies such as in the Hutton, Precipice, and Namur sandstones. There is probably a dual source for oil, from the underlying Permian (which may be the dominant source in the Surat Basin), and from shales deposited in shallow, partly oxygenated lakes and overbank facies of Jurassic age (important in the Eromanga, and possibly subordinate in the Surat Basin). Deep lacustrine facies, typical of the Chinese basins, did not develop. The greater abundance of oil in the Chinese nonmarine basins is explained in terms of tectonic and palaeoclimatic factors which yielded thicker and better quality source rocks, more rapid maturation, and a better juxtaposition of source rocks and good-quality reservoirs, thus providing short, highly efficient migration routes.

Sandstone bodies sedimentary characteristics of Shanxi formation, at Chengjiazhuang section in Liulin, Shanxi province, China

2015 ◽  
Vol 12 (2) ◽  
pp. 177-188
Author(s):  
Chao Jin ◽  
LangTao Liu ◽  
GuoQiang Hao ◽  
Kuo Cao
Keyword(s):  
Sedimentary Environment ◽  
Ordos Basin ◽  
Field Measurements ◽  
Sedimentary Facies ◽  
Shanxi Province ◽  
Sample Collection ◽  
Sedimentary Characteristics ◽  
Sample Composition ◽  
Sedimentary Microfacies ◽  
Distributary Channel

Sedimentary facies type of the Shanxi Formation in northeastern Ordos Basin is an ongoing debate. Based on field measurements, sample collection and identification, and laboratory analysis, we systematically evaluated the sedimentary characteristics of the sandstone bodies of Shanxi Formation of Chengjiazhuang section in Liulin. Analysis included identifying sample composition, grain size, texture, sedimentary structure and spatial distribution. We came to the conclusion that the sedimentary environment of Shanxi Formation is deltaic. This deltaic environment included deltaic front and deltaic plain. It can be further divided into five sedimentary microfacies: subfluvial distributary channel, subfluvial distributary interchannel, distributary channel, levee, and peat bog. And lastly, the evolution of sedimentary environment of Shanxi Formation is discussed.

Study of the Fluvial Facies Reservoir Sedimentary Characteristics of an Oil Field in China

2013 ◽  
Vol 753-755 ◽  
pp. 66-69
Author(s):  
Sheng Yun Yu ◽  
Qing Yun Meng ◽  
Hai Ying Xu
Keyword(s):  
Sedimentary Environment ◽  
Sedimentary Facies ◽  
Flood Plain ◽  
Oil Field ◽  
Distribution Model ◽  
River Sand ◽  
Meandering River ◽  
Sedimentary Characteristics ◽  
Sedimentary Model ◽  
Sand Body

In this paper, 6 kinds of reservoir sedimentary microfacies distribution model-conceptual model have been established by the use of reservoir sedimentology theory and methods, namely, large sandy braided river sand body sedimentary model, large meandering river sand body sedimentary model, low bending-straight distributary channel sedimentary model, crevasse splay (crevasse river) sedimentary model, heart beach sedimentary model, flood plain and distributary plain sheet sand body sedimentary model. On this basis, the sedimentary facies figures of four sedimentary units have been painted, putting forward the evolution law of sedimentary environment in the research zone, thus providing basic data for the facies control modeling.

High Resolution Sequence Stratigraphy Characteristics and Distribution of Donghe Sandstone in Qunkuqiake Region in Tarim Basin

2014 ◽  
Vol 1044-1045 ◽  
pp. 570-573
Author(s):  
Mu Wei Cheng
Keyword(s):  
Tarim Basin ◽  
High Frequency ◽  
Oil And Gas ◽  
Sedimentary Environment ◽  
Sedimentary Facies ◽  
Sequence Stratigraphic ◽  
Sedimentary Characteristics ◽  
Sand Body ◽  
Frequency Sequence ◽  
High Resolution Sequence Stratigraphy

Qunkuqiake Region is an important exploration block in Tarim Basin. Donghe Sandstone is the main oil and gas target stratum. In order to reveal the rules of migration of the sand body and predict the favorable reservoir accurately, two high-frequency cycles are identified in Donghe Sandstone each of which consists of rising hemicycle and descending hemicycle, the sedimentary characteristics are analysed within the sequence stratigraphic framework and the barrier bar subfacies are identified beginning with the sedimentary characteristics of glutenite through the study of drilling stratigraphic section using drilling data, well logging data and cores data. This paper has disclosed the transition of the sedimentary environment from barrier-free coast system to barrier coast system during the period from rising hemicycle to descending hemicycle and the planar distribution of sedimentary facies of different high frequency sequence of Donghe Sandstone.

Sedimentary, Geochemical and Micropaleontological Responses to Sea Level Variations in the Vitoria Estuary, Espírito Santo

Radiocarbon ◽  
2018 ◽  
Vol 60 (2) ◽  
pp. 583-600 ◽  
Author(s):  
Giseli Modolo Vieira Machado ◽  
Alex Cardoso Bastos ◽  
Alex da Silva de Freitas ◽  
Jose Antônio Baptista Neto
Keyword(s):  
Organic Matter ◽  
Sea Level ◽  
Higher Plants ◽  
Sediment Cores ◽  
Sedimentary Facies ◽  
Sedimentary Deposits ◽  
Sea Level Oscillations ◽  
Continental Source ◽  
Transport Patterns ◽  
The Moment

AbstractMarine insertion indicators in the Vitoria estuary (ES) revealed relative variations in sea level during the Holocene in three sediment cores. Sedimentological, geochemical (C/N ratio), and paleontological (shells and palynomorphs) analysis and 14C dating associated five sedimentary facies to different estuarine deposits. A C/N ratio <10 at the core base indicated organic matter of marine origin. Moving up the cores to 110–150 cm, an abrupt increase in C/N to 26–63 in every core suggests the sudden entry of higher plants into the estuary, potentially the moment sea level retreated. High continental (10,743 palynomorphs/g) and low marine palynomorph concentrations (323 palynomorphs/g) suggest a primarily continental source even during transgression and at high sea level. Around 8973 cal BP, an open bay already existed in the region of Vitoria. Sea level potentially exceeded the current level around 7110 cal BP. The transgressive maximum was at 5567 cal BP. Marine insertion indicators, such as marine shells, low C/N ratios and foraminiferal linings, did not always respond directly to sea level oscillations. These discrepancies probably result from lateral variations in sedimentary deposits from transport patterns and from variations in organic matter and palynomorph preservation due to differences in river and obstacle proximity.

scholarly journals Biomarkers geochemistry of the Alpagut oil shale sequence: an evaluation of dispositional environments and source rock potential from Dodurga-Çorum basin (N-Turkey)

2022 ◽  
Author(s):  
S. Korkmaz ◽  
R. Kara-Gülbay ◽  
T. Khoitiyn ◽  
M. S. Erdoğan
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Oil Shale ◽  
Sedimentary Environment ◽  
Organic Matter Content ◽  
Type I ◽  
Terrestrial Organic Matter ◽  
High Hydrogen ◽  
Oil Shales ◽  
Biomarker Data

AbstractThe Cenozoic Çankırı-Çorum basin, with sedimentary facies of varying thickness and distribution, contains raw matters such as coal deposits, oil shales and evaporate. Source rock and sedimentary environment characteristics of the oil shale sequence have been evaluated. The studied oil shales have high organic matter content (from 2.97 to 15.14%) and show excellent source rock characteristics. Oil shales are represented by very high hydrogen index (532–892 mg HC/g TOC) and low oxygen index (8–44 mgCO2/g TOC) values. Pyrolysis data indicate that oil shales contain predominantly Type I and little Type II kerogen. The biomarker data reveal the presence of algal, bacterial organic matter and terrestrial organic matter with high lipid content. These findings show that organic matters in the oil shales can generate hydrocarbon, especially oil. High C26/C25, C24/C23 and low C22/C21 tricyclic terpane, C31R/C30 hopane and DBT/P ratios indicate that the studied oil shales were deposited in a lacustrine environment, and very low Pr/Ph ratio is indicative of anoxic character for the depositional environment. Tmax values from the pyrolysis analysis are in the range of 418–443 °C, and production index ranges from 0.01 to 0.08. On the gas chromatography, high Pr/nC17 and Ph/nC18 ratios and CPI values significantly exceeding 1 were determined. Very low 22S/(22S + 22R) homohopane, 20S/(20S + 20R) sterane, diasterane/sterane and Ts/(Ts + Tm) ratios were calculated from the biomarker data. Results of all these analyses indicate that Alpagut oil shales have not yet matured and have not entered the oil generation window.

scholarly journals Characteristics and Geological Significance of the Hydrocarbon Source Rocks of the Qum Formation in Outcrop of the Northern Garmsar Area, Iran

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 1) ◽  
Author(s):  
Xiaojun Li ◽  
Jingchun Tian ◽  
Miao Wang ◽  
Yong Chen
Keyword(s):  
Organic Matter ◽  
Vitrinite Reflectance ◽  
Sedimentary Environment ◽  
Source Rocks ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Soluble Organic Matter ◽  
The North ◽  
History Of ◽  
Formation Conditions

Abstract The carbonate rocks were collected from the Qum Formation in outcrop of the northern Garmsar Area, Iran. In order to evaluating the hydrocarbon generation prospects of these source rocks, we analyzed their geochemical characteristics, including the abundance, type, and maturity of organic matter, and investigated their formation conditions by analyzing the characteristics of soluble organic matter and sedimentary environment. The results show that the organic matter abundance of the source rocks in the Qum Formation in the Garmsar Area is low in the north and west. The organic matter type is mainly II1-II2, locally showing type I and III, and in general, it is conducive to hydrocarbon generation. The maturity of organic matter is low, showing the Tmax between 416°C and 439°C, vitrinite reflectance (Ro) from 0.49% to 0.83%, which indicate it is at the stage of low to moderate maturity. The soluble organic matter characteristics indicated that the organic matter evolution of the source rocks in the Qum Formation is low. Through comparison between the study area and other areas, and different places within the working area, the abundance, type, and maturity of organic matter of the source rocks in the Qum Formation are different, caused by the basin facie zones, sedimentary environment, and history of sedimentation of the source rocks. Overall, the source rock in the Qum Formation in Garmsar Area has good prospects of hydrocarbon generation. This study has important significance for further exploration in the Garmsar Area.

Sign in / Sign up

Export Citation Format

Share Document