scholarly journals Influence of organic matter type on porosity development in the Wufeng-Longmaxi Shale: A combined microscopy, neutron scattering and physisorption approach

2021 ◽  
pp. 103880
Author(s):  
Claudio Delle Piane ◽  
Humera Ansari ◽  
Zhongsheng Li ◽  
Jitendra Mata ◽  
William Rickard ◽  
...  
Keyword(s):  
Organic Matter ◽  
Neutron Scattering ◽  
Longmaxi Shale ◽  
Organic Matter Type ◽  
Combined Microscopy ◽  
Porosity Development

scholarly journals The Role of Organic Matter on Uranium Precipitation in Zoovch Ovoo, Mongolia

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 310 ◽  
Author(s):  
Dimitrios Rallakis ◽  
Raymond Michels ◽  
Marc Brouand ◽  
Olivier Parize ◽  
Michel Cathelineau
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Late Cretaceous ◽  
Uranium Deposit ◽  
Vitrinite Reflectance ◽  
Driven Systems ◽  
Sem Observation ◽  
Organic Matter Type ◽  
Clay Layers

The Zoovch Ovoo uranium deposit is located in East Gobi Basin in Mongolia. It is hosted in the Sainshand Formation, a Late Cretaceous siliciclastic reservoir, in the lower part of the post-rift infilling of the Mesozoic East Gobi Basin. The Sainshand Formation corresponds to poorly consolidated medium-grained sandy intervals and clay layers deposited in fluvial-lacustrine settings. The uranium deposit is confined within a 60- to 80-m-thick siliciclastic reservoir inside aquifer driven systems, assimilated to roll-fronts. As assessed by vitrinite reflectance (%Rr < 0.4) and molecular geochemistry, the formation has never experienced significant thermal maturation. Detrital organic matter (type III and IV kerogens) is abundant in the Zoovch Ovoo depocenter. In this framework, uranium occurs as: (i) U-rich macerals without any distinguishable U-phase under SEM observation, containing up to 40 wt % U; (ii) U expressed as UO2 at the rims of large (several millimeters) macerals and (iii) U oxides partially to entirely replacing macerals, while preserving the inherited plant texture. Thus, uranium is accumulated gradually in the macerals through an organic carbon–uranium epigenization process, in respect to the maceral’s chemistry and permeability. Most macerals are rich in S and, to a lesser extent, in Fe. Frequently, Fe and S contents do not fit the stoichiometry of pyrite, although pyrite also occurs as small inclusions within the macerals. The organic matter appears thus as a major redox trap for uranium in this kind of geological setting.

Accumulation Factors Analysis of Coal-Bearing Strata Shale Gas in Qinshui Basin

2013 ◽  
Vol 868 ◽  
pp. 121-124 ◽  
Author(s):  
Jun Yuan ◽  
Yan Bin Wang ◽  
Xin Zhang ◽  
Jing Jing Fan ◽  
Pei Xue
Keyword(s):  
Organic Matter ◽  
Mineral Composition ◽  
Shale Gas ◽  
Vitrinite Reflectance ◽  
Qinshui Basin ◽  
Factors Analysis ◽  
Upper Paleozoic ◽  
Organic Matter Type ◽  
Organic Matter Abundance

The Shanxi and Taiyuan formations in Permo-Carboniferous of upper Paleozoic Erathem of Qinshui Basin, not only has abundant coal and CBM resources, also has a lot of shales. By analyzing the shale thickness, organic matter type, organic matter abundance, vitrinite reflectance, mineral composition of the Permo-Carboniferous coal-bearing strata, considered that the shale thickness of coal-bearing strata in the Qinshui Basin is larger, the organic matter abundance is general, but maturity is high and full of rich brittle mineral. It is in favor of late fracturing.

THE ORIGINS OF COASTAL BITUMENS FROM WESTERN AUSTRALIA

1994 ◽  
Vol 34 (1) ◽  
pp. 787
Author(s):  
R. Alexander ◽  
T.J. Currie ◽  
R.I. Kagi
Keyword(s):  
Organic Matter ◽  
Crude Oil ◽  
Source Rock ◽  
Western Australia ◽  
Se Asia ◽  
Indonesian Archipelago ◽  
Organic Matter Type ◽  
Oil Seep ◽  
Australian Coastline ◽  
Depositional Setting

A total of 83 samples of stranded bitumens collected from the western and southern coasts of Western Australia have been classified into eight groups on the basis of their biomarker compositions. The source rock characteristics inferred for these bitumens, in terms of organic matter type and depositional setting indicated by the biomarkers, suggest strongly that the bitumens originate from a variety of areas in SE Asia in the vicinity of the Indonesian archipelago. In fact, in seven of the eight cases a good correlation is observed between biomarker composition of each bitumen group and a produced crude oil or oil seep from this region. The bitumens are transported to and around the Australian coastline by a system of ocean currents.

The Relationships between Uranium Mineralization and Organic Matter in 373 Uranium Deposit

2014 ◽  
Vol 962-965 ◽  
pp. 203-207 ◽  
Author(s):  
Ping Li ◽  
Zheng Qi Xu ◽  
Ye Wang ◽  
Peng Chong Wang
Keyword(s):  
Organic Matter ◽  
Rock Type ◽  
Uranium Deposit ◽  
Thermal Evolution ◽  
Uranium Content ◽  
Uranium Mineralization ◽  
Pelitic Rock ◽  
Organic Matter Type ◽  
Main Component ◽  
The Relationship

The 373 deposit,as a typical carbonanceous-siliceous-pelitic rock type uranium deposit,is rich in organic matter and pyrite.Close relationships exist between organic matter and uranium mineralization in a lot of uranium deposits. But few people have studied the relationship between uranium mineralization and organic matter of carbonanceous-siliceous-pelitic rock type uranium deposit.The organic matter type of 373 uranium deposit is type-II2.The sources of organic matter are mainly marine plankton,microbial and terrestrial plant. The organic maturity is relatively low,at the immature-low mature stage.Compared with the surrounding rock ,the ore has gone through higher paletemperature on account of hydrothermal and fault. The type and the maturity of organic matter result in the generation of large amount of humic acid during thermal evolution that could be preserved in strata. The contents of chloroform bitumen “A” of organic matter in the mineralized layer are 0.47—10.42ug/g .Asphaltene is the main component of chloroform bitumen “A”.The correlation between chloroform bitumen “A” and uranium content is high,as well as the correlation between the content of asphaltene and uranium content. Study shows that the functions of organic matter in 373 uranium deposit are mainly adsorption,complexation and reduction.

Programmed pyrolysis (Rock-Eval) data and shale paleoenvironmental analyses: A review

2015 ◽  
Vol 3 (1) ◽  
pp. SH41-SH58 ◽  
Author(s):  
B. S. Hart ◽  
A. S. Steen
Keyword(s):  
Organic Matter ◽  
Petroleum Industry ◽  
Organic Content ◽  
Type I ◽  
Type Iv ◽  
Marine Organic Matter ◽  
Depositional Settings ◽  
Organic Matter Type ◽  
Rock Eval ◽  
Original Organic Matter

We use public-domain data from programmed pyrolysis, collected using Rock-Eval or similar apparatuses, to illustrate the utility and challenges of using this method for paleoenvironmental analyses. These data are widely available and commonly collected and analyzed for a variety of purposes in the petroleum industry in the fields of paleo-oceanography and paleoclimate research and elsewhere. We show how factors such as sample condition, mineralogy, organic content, and others can influence the results, leading to potential interpretational complications. We also evaluate ways that the data can be plotted to maximize their utility for interpretation purposes. Four types of organic matter are commonly identified based on programmed pyrolysis results. Type I organic matter has a high (e.g., [Formula: see text]) hydrogen index (HI), is oil-prone and is commonly assumed to represent lacustrine depositional settings. Type II organic matter is also oil-prone (i.e., having an HI between 350 and 700) but is commonly assumed to represent marine organic matter. Type III organic matter has a lower HI ([Formula: see text]), will tend to generate gas, and is commonly assumed to represent terrigenous (e.g., land plants) organic matter. Type IV organic matter has very low HI values and is associated with nongenerative (i.e., inert) organic matter. We show that these simple associations between organic matter type and paleoenvironment were not always valid. Preburial degradation of the organic matter and mixing of different organic matter types are two possibilities that can lead to erroneous paleoenvironmental interpretations. Furthermore, the programmed pyrolysis results characterize the present composition of the organic matter which, especially at high thermal maturities (e.g., dry gas window), can be significantly different to that of the original organic matter. Other types of advanced geochemical and sedimentologic analyses should be integrated with the programmed pyrolysis results during their interpretation.

Sign in / Sign up

Export Citation Format

Share Document