Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the ...Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin,while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock,which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance,while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a relatively rich humic type substance.展开更多
The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samp...The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogemc sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.展开更多
Highly-mature carbonate source rock is essential to the exploration of oil and gas in southern China. In this study, the carbonate strata in the relatively well-developed Lower Permian Chihsia Formation (located in Ch...Highly-mature carbonate source rock is essential to the exploration of oil and gas in southern China. In this study, the carbonate strata in the relatively well-developed Lower Permian Chihsia Formation (located in Chaohu, Lower Yangtze) were targeted, and the formation and influencing factors of source rock were discussed based on paleoenvironment reconstruction using comprehensive sedimentology, palynofacies, and organic geochemistry data. The results demonstrate that the Chihsia Formation is oxygen-deficient biogenic carbonate sediments, with marked variations in the organic and inorganic components, formed during a period of Permian transgression. The formation of source rock is the combined result of high bioproductivity and oxygen-deficient environment generated by transgression and oxygenation events which frequently occurred during transgression periods. Source rock was affected by self-dilution effects and diagenesis, causing its heterogeneous distribution in many intervals. Source rock is over 40 m thick, and can be identified based on its different organic, biological, and mineral composition characteristics. The carbonate rock appears to require no specific clay content in order to become a source rock. The combination of sedimentology, palynofacies, and organic geochemistry has provided an effective means for evaluating and predicting high-maturity carbonate source rock in the region.展开更多
基金Project 2009011 supported by the Resource Exploration Projects of the Ministry of Land and Resources of Chinathe State Key Laboratory of Petroleum Resource and Prospecting of China Petroleum University (Beijing)
文摘Based on analyses of the components of crude oil hydrocarbons and carbon isotopes,the content of normal alkane decreased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin,while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock,which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance,while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a relatively rich humic type substance.
基金Supported by China Postdoctoral Science Foundation (No. 2005037621)the National Science Foundation of China (No. 40206015)Fork Ying Tong Education Foundation (No.94002), and the International (CBI) through Fellowship to J. L. Zhou
文摘The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogemc sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.
基金supported by the National Natural Science Foundation of China (Grant No. 40872089)Science and Technology Office Fund of China Petroleum & Chemical Co., Ltd. (Grant No. G080007ZS188)the National Oil and Gas Special Fund (Grant No. 2008ZX05023-003)
文摘Highly-mature carbonate source rock is essential to the exploration of oil and gas in southern China. In this study, the carbonate strata in the relatively well-developed Lower Permian Chihsia Formation (located in Chaohu, Lower Yangtze) were targeted, and the formation and influencing factors of source rock were discussed based on paleoenvironment reconstruction using comprehensive sedimentology, palynofacies, and organic geochemistry data. The results demonstrate that the Chihsia Formation is oxygen-deficient biogenic carbonate sediments, with marked variations in the organic and inorganic components, formed during a period of Permian transgression. The formation of source rock is the combined result of high bioproductivity and oxygen-deficient environment generated by transgression and oxygenation events which frequently occurred during transgression periods. Source rock was affected by self-dilution effects and diagenesis, causing its heterogeneous distribution in many intervals. Source rock is over 40 m thick, and can be identified based on its different organic, biological, and mineral composition characteristics. The carbonate rock appears to require no specific clay content in order to become a source rock. The combination of sedimentology, palynofacies, and organic geochemistry has provided an effective means for evaluating and predicting high-maturity carbonate source rock in the region.