Quantitative reconstruction of the palaeoclimate of the Shahejie Formation in the Chezhen Depression, Bohai Bay Basin, eastern China

Author(s):  
Tao Chen ◽  
Jinliang Zhang ◽  
Yang Li ◽  
Yongfu Zhao
2018 ◽  
Vol 6 (4) ◽  
pp. SN11-SN21
Author(s):  
Zhenkai Huang ◽  
Maowen Li ◽  
Quanyou Liu ◽  
Xiaomin Xie ◽  
Peng Liu ◽  
...  

Systematic organic petrology and geochemistry analyses have been conducted in the source rocks of the lower Es3 and upper Es4 members of the Shahejie Formation in the Niuzhuang Sub-sag, Jiyang Depression, Bohai Bay Basin, eastern China. The results indicate that the main organic types of shale and nongypsum mudstone in the lower Es3 and upper Es4 member are I-II1 kerogen, and the predominant ([Formula: see text]) activation energy frequencies range from 57 to [Formula: see text]. The similar distribution characteristics in the two source rocks indicate that they have a similar hydrocarbon maturation process. An extensive pyrolysis analysis indicates that the source rocks of the upper Es4 member do not have an obvious double peak hydrocarbon generation model. Previous studies indicate that the hydrocarbon index peak at a depth of 2500–2700 m is affected by migrating hydrocarbon. Major differences are not observed in the hydrocarbon generation and evolution process of the shale and nongypsum mudstone. The primary oil generation threshold of the lower Es3 and upper Es4 members is approximately 3200 m, and the oil generation peak is approximately 3500 m. The activation energy distribution of the gypsum mudstone of the upper Es4 member is wider than that of the shale and nongypsum mudstone, and lower activation energies account for a larger proportion of the activation energies. The above factors may lead to a shallower oil generation threshold for gypsum mudstone compared with that for shale and nongypsum mudstone.


2020 ◽  
Vol 600 (1) ◽  
pp. 012007
Author(s):  
Fu Deliang ◽  
Sun Lina ◽  
Xu Guosheng ◽  
Liang Haoran ◽  
Zhang Chen ◽  
...  

Abstract In this study, the influence of organic matter and inorganic matter on the pore structure of the Shahejie Formation (E2-3S) shale in the Bohai Bay Basin, was analysed. The pore characteristics, including the BET surface area, BJH adsorption cumulative volume and average pore diameter of the original samples, extracted samples, H2O2-treated samples and kerogen samples, were analysed with low-pressure N2 adsorption experiment. The study showed that the soluble organic matter in low-maturity shale blocked a certain number of pores, which mainly had pore sizes below 5 nm. The solid organic matter mainly formed pore diameters of 1-2 nm and pore diameters larger than 10 nm. A large amount inorganic pore diameter in the ranges of less than 0.8 nm, 1-2 nm, and 2.3-20 nm was blocked by solid organic matter. The micropores formed by minerals were much more abundant than those formed by organic matter in the terrestrial low-maturity shale. The symbiotic relationship between the minerals and the organic matter led to a decrease in the specific surface area and pore volume of the terrestrial low-maturity shale.


2016 ◽  
Vol 9 (3) ◽  
Author(s):  
Dawei Lv ◽  
Mingzhen Zhang ◽  
Huiyong Wang ◽  
Guangzeng Song ◽  
Ziqun Zhou ◽  
...  

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