Geochemical characteristics and sedimentary setting of chang 9 shale in the Upper Triassic Yanchang Formation of southeastern Ordos Basin (NW China)
Geochemical characteristics and sedimentary setting of chang 9 shale in the Upper Triassic Yanchang Formation of southeastern Ordos Basin (NW China)
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鄂尔多斯盆地东南部上三叠统延长组长9页岩地球化学特征及沉积背景
DOI：
10.1016/j.petrol.2020.108081
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发表时间：
2021-01
影响因子：
--
通讯作者：
Tong Xu
中科院分区：
文献类型：
--
作者：
Yuhang Chen;Shehu Liu;Zengwu Zhu;Zhe Wang;Xiaoguang Sun;Tong Xu
除了鄂尔多斯盆地长7段(长7段)富含有机质的页岩外，长9段(长9段)页岩是另一种烃源岩和潜在的非常规目标。然而，对于Ch9页岩的特征和潜力，人们普遍缺乏共识。为了确定长9页岩的潜力，在综合分析地球化学和沉积相的基础上，对其古环境和沉积环境进行了分析。通过对比长9页岩和富含有机质的长7页岩的地球化学特征，评价了长9页岩有机质(OM)富集的控制因素。结果表明，沙九段页岩具有良好的含油气远景，陆源有机质是长九段页岩有机质的重要组成部分。沙九段页岩沉积于气候由冷干向暖湿过渡时期，水体处于缺氧-缺氧-淡水状态。Ch9期相对寒冷干燥的气候和缺氧缺水条件不能提供与Ch7期相同的有机质富集的良好条件。Ch9页岩由沉积与来自大陆岛弧和活动大陆边缘的长英质岩石混合而成。活动的构造环境导致了沉积过程中的事件沉积(如浊流和热液活动)。浊流携带的陆源有机质的输入也促进了有机质的富集化，但浊流引起的很高的沉积速率稀释了有机质，这可能抵消了热液对有机质富集度的影响。研究结果有助于揭示长9段页岩的生油潜力，为鄂尔多斯盆地页岩油气勘探提供理论依据。
In addition to the organic-rich shale in the Chang 7 Member (Ch7 shale) of the Ordos Basin, the shale hosted in the Chang 9 Member (Ch9 shale) is another source rock and potential unconventional target. However, there is a general lack of consensus on the features and potential of the Ch9 shale. In order to determine the potential of the Ch9 shale, this study analyzes its paleoenvironment and sedimentary setting based on the integrated analysis of geochemistry and sedimentary facies. A comparison of geochemical features between the Ch9 shale and the organic-rich Ch7 shale is made to evaluate the factors controlling organic matter (OM) enrichment of the Ch9 shale. The results show that the Ch9 shale has good hydrocarbon potential, and terrestrial OM is important component of the OM in the Ch9 shale. The Ch9 shale was deposited in climatic transition period from cold and dry to warm and humid, when the water body was suboxic-anoxic and freshwater. The relatively cold and dry climate and suboxic-anoxic water condition in the Ch9 period could not provide the same excellent conditions for OM enrichment as that in the Ch7 period. The Ch9 shale is composed of sediments mixed with felsic rocks that originated from continental island arcs and active continental margins. The active tectonic setting resulted in event deposition (e.g. turbidity flows and hydrothermal fluid activity) during the deposition of Ch9 shale. The input of terrestrial OM carried by turbidity flows also promoted OM enrichment, however, the very high depositional rates caused by turbidity flows diluted the OM, which probably offset the effect of hydrothermal on OM enrichment. Our results are helpful to revealing the source potential of the Ch9 shale, providing a theoretical basis for the shale oil and gas exploration in the Ordos Basin.
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DOI：
10.1016/j.palaeo.2014.06.005
发表时间：
2014-09-15
影响因子：
3
作者：
Cantalejo, Blanca;Pickering, Kevin T.
通讯作者：
Pickering, Kevin T.
影响因子：
2.9
作者：
R. Henrich;Y. Cherubini;H. Meggers
通讯作者：
R. Henrich;Y. Cherubini;H. Meggers
将秦岭造山运动与长7页岩（三叠系延长组）沉积联系起来：来自主量、微量和稀土元素地球化学的证据
影响因子：
1.8
作者：
Yuan Wei;Chen Ruiqian;Liu Guangdi;Shang Fei;Xu Liming;Niu Xiaobing
通讯作者：
Niu Xiaobing
影响因子：
1.5
作者：
N. Purevjav;B. Roser
通讯作者：
N. Purevjav;B. Roser
DOI：
--
发表时间：
1985
期刊：
Oil & Gas Science and Technology-revue De L Institut Francais Du Petrole
影响因子：
--
作者：
J. Espitalie;G. Deroo;F. Marquis
通讯作者：
J. Espitalie;G. Deroo;F. Marquis