Geochemical Characteristics of Oil and Source Rock, Origin and Genesis of Oil in Xihu Depression, East China Sea Basin
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摘要: 东海盆地西湖凹陷具有大量的原油资源，但对于原油成因讨论较少.采集西湖凹陷多个油样和岩样，利用气相色谱和傅里叶红外光谱等手段，全面分析了该区烃源岩和原油的地球化学特征，综合讨论了原油来源以及凝析油和高蜡轻质油的成因.研究结果表明，平湖组煤系源岩均处于热演化的成熟阶段，其中碳质泥岩和煤岩以陆源生物为主要生源，其干酪根类型为Ⅲ型，暗色泥岩则具有陆源生物和水生生物双重生源贡献，其干酪根类型Ⅱ-Ⅲ型，同时碳质泥岩和煤的生油潜力远高于泥岩.原油主要为凝析油和轻质油，凝析油具有低密度、低蜡等“六低一高”的特点，轻质油具有高蜡特质，而且轻烃组分有明显差异.生标参数显示大部分原油为腐殖型，少部分原油表现出具有腐殖和腐泥母质的特点，同时该区原油均处于中等成熟阶段.油油对比和油岩对比表明大部分油来自平湖组碳质泥岩和煤岩，具有典型Ⅲ型腐殖油的特征；少部分油来自暗色泥岩，具有Ⅱ-Ⅲ型油的特征(总体上仍偏腐殖型).凝析油和轻质油的物性及轻烃组分的差异与源岩母质无关.凝析油是干酪根在成熟演化阶段生成的原油遭受蒸发分馏作用的结果，高蜡轻质油除了是“蒸发分馏作用”的残余油外，还有部分是“混合作用”的结果.Abstract: There are plenty of oil in Xihu depression of East China Sea basin, however, few scholars pay attention to the origin and genesis of oil. The samples of source rocks and oil were measured by gas chromatography and Fourier transform infrared spectroscopy (FTIR), and the origin of oil and genesis of condensate and high-wax light oil are discussed based on the analysis of geochemical characteristics. The results suggest that coal measure source rocks of the Pinghu Formation are at the mature stage of thermal evolution. Carbonaceous mudstone and coal mainly came from terrestrial organism, with kerogen type Ⅲ. Dark mudstone mainly came from both terrestrial organism and aquatic organism, with kerogen type Ⅱ-Ⅲ. Genetic potential of carbonaceous mudstone and coal is significantly higher than that of mudstone. The crude oil is mainly divided into condensate with low density and wax and high-wax light oil, and light hydrocarbon displays obvious different compositions. Most of the oil is of humic type with some oil being both humic and sapropelic. Oil is at the medium mature stage. Most oil is derived from carbonaceous mudstone and coal in the Pinghu Formation, whereas only a small amount of oil is derived from dark mudstone. Physical properties of condensate and light oil and their difference of light hydrocarbon composition are unrelated with source rocks. Condensate was produced under the evaporation fractionation effect and from the oil which had been generated from the kerogen at the mature stage. High-wax light oil is residual oil from evaporation fractionation effect, and some oil has experienced mixing.
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Key words:
- Xihu depression /
- geochemistry /
- origin /
- genesis /
- petroleum geology
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图 1 西湖凹陷构造分带、油气田分布及地层
Fig. 1. Various structural belts and oil-gas fields and simplifed chart of strata in Xihu depression
图 2 西湖凹陷典型暗色泥岩(a)和煤岩的饱和烃气相色谱(b)
a.NB25-3-1井泥岩3 226~3 228 m，平湖组；b.NB25-3-1井煤3 438~3 446 m，平湖组
Fig. 2. Gas chromatogram of saturated hydrocarbon of typical dark mudstone (a) and coal (b) in Xihu depression
图 3 西湖凹陷平湖组相近深度泥岩、碳质泥岩和煤的红外光谱谱形
Fig. 3. Infrared spectroscopy spectrum chart of mudstone, carbonaceous mudstone and coal in similar depth in Pinghu Formation, Xihu depression
图 4 西湖凹陷平湖组泥岩、碳质泥岩和煤岩干酪根红外吸收峰强度比值分布
Fig. 4. Infrared absorption peak intensity ratio of mudstone, carbonaceous mudstone and coal in Pinghu Formation, Xihu depression
图 5 干酪根镜质体反射率与C=C键红外吸收最小波数Wmin之间关系
Fig. 5. Relationship between kerogenvitrinite reflectance and infrared absorption minimum wave number (Wmin) of C=C bond
图 6 西湖凹陷HY14-1-1井(3 031.15~3 063.10 m)原油样品PVT相图(a)和原油密度与含蜡量的关系(b)
Fig. 6. PVT phase diagram of crude oil samples in HY14-1-1 well (a) and relationship of density and wax content of crude oil (b), Xihu depression
图 7 西湖凹陷不同原油的轻烃的气相色谱
a.平湖五井深度为3 695.5 m的原油；b.平湖四井深度为2 708.6 m的原油
Fig. 7. Gas chromatogram of light hydrocarbons of different crude oil in Xihu depression
图 8 西湖凹陷不同原油甾烷化合物分布
a.残雪四井原油；b.平湖五井原油
Fig. 8. Distribution of steranes of different crude oil in Xihu depression
图 9 西湖凹陷原油、暗色泥岩、碳质泥岩和煤岩的Ph/nC18和Pr/nC17的分布(a)和饱和烃与芳香烃的碳同位素关系(b)
Fig. 9. Distribution of Ph/nC18 and Pr/nC17 (a) and diagram of carbon isotope of saturated hydrocarbons and aromatic (b) of crude oil, dark mudstone, carbonaceous mudstone and coal rocks in Xihu depression
图 10 西湖凹陷原油Pr/Ph与含蜡量关系
Fig. 10. Diagram of Pr/Ph and wax content of crude oil in Xihu depression
图 11 西湖凹陷原油次生变化识别(a)和正构烷烃碳数与摩尔分数分布(b)
Fig. 11. Dentification of secondary changes in crude oil (a) and distribution of n-alkane carbon number and the molar fraction (b) in Xihu depression
图 12 西湖凹陷凝析油和高蜡油的成因模式
Fig. 12. Genesis of condensate and high wax oil in Xihu depression
表 1 西湖凹陷原油油样的成熟度参数
Table 1. Maturity parameters of crude oil samples in Xihu depression
计算参数 轻烃参数 芳烃参数 生标成熟度参数 Temp(℃) Rm(%) MPI-1 RMPI-1(%) Ts/Tm C29甾20S/(20S+20R) C29甾ββ/(αα+ββ) 范围 119~137 0.82~1.03 0.38~1.22 0.6~1.1 0.77~1.36 0.39~0.64 0.41~0.75 注：Temp=140+15[ln(2, 4-DMP/2, 3-DMP)](Mango, 1990)；Ro=0.012 3 Tmax-0.676 4(Mukhopadhyay and Dow, 1994)；RMPI-1=0.6MPI-1+0.37. 
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[1] Connan, J., Cassou, A.M., 1980. Properties of Gases and Petroleum Liquids Derived from Terrestrial Kerogen at Various Maturation Levels. Geochimica et Cosmochimica Acta, 44(1): 1-23. doi: 10.1016/0016-7037(80)90173-8 [2] Chen, J.P., Huang, D.P., Li, J.C., et al., 1999. The Petroleum Generation Model for Organic Matter from Jurassic Coal Measure, Northwest China. Geochimica, 28(4): 327-339 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQHX199904003.htm [3] Fu, N., Li, Y.C., Chen, G.H., et al., 2003. Pooling Mechanisms of "Evaporating Fractionation" of Oil and Gas in the Xihu Depression, East China Sea. Petroleum Exploration and Development, 30(2): 39-42 (in Chinese with English abstract). http://www.zhangqiaokeyan.com/academic-journal-cn_petroleum-exploration-development_thesis/0201218207521.html [4] Ganz, H.H., Kalkreuth, W., 1991. IR Classification of Kerogen Type, Thermal Maturation, Hydrocarbon Potential and Lithological Characteristics. Journal of Southeast Asian Earth Sciences, 5(1): 19-28. doi: 10.1016/0743-9547(91)90007-K [5] Gong, D.Y., Li, M., Li, Q.M., et al., 2014. Geochemical Characteristics and Origins of the Oils in Wushi Sag, Tarim Basin. Natural Gas Geoscience, 25(1): 62-69 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-TDKX201401009.htm [6] Hou, Q.J., Feng, Z.H., Huo, Q.L., 2004. Oil Migration Model and Entrapment Epoch of North Wuerxun Depression in Hailaer Basin. Earth Science—Journal of China University of Geosciences, 29(4): 397-403 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX200404003.htm [7] Jia, J.Y., Xu, X.H., Sun, B.Q., 2000. Oil/Gas Geochemical Characters in the Xihu Trongh of the East China Sea. Offshore Oil, 20(2): 1-7 (in Chinese with English abstract). [8] Kissin, Y., 1987. Catagenesis and Composition of Petroleum: Origin of N-Alkanes and Isoalkanes in Petroleum Crude Oils. Geochimica et Cosmochimica Acta, 51: 2445-2457. doi: 10.1016/0016-7037(87)90296-1 [9] Lei, C., Ye, J.R., Wu, J.F. et al., 2014. Dynamic Process of Hydrocarbon Accumulation in Low-Exploration Basins: A Case Study of Xihu Depression. Earth Science—Journal of China University of Geosciences, 39(7): 837-847 (in Chinese with English abstract). doi: 10.3799/dqkx.2014.078 [10] Li, X.Q., Zhong, N.N., Xiong, B., et al., 1997. A Study on Coal Series Source Rock Organic Geothermal Evolution of Xihu Sag. Coal Geology of China, 9(1): 33-36 (in Chinese with English abstract). http://www.researchgate.net/publication/313707800_A_Study_on_Coal_Series_Source_Rock_Organic_Geothermal_Evolution_of_Xihu_Sag [11] Li, Y., Wang, Y.P., Zhao, C.Y., et al., 2013. The FTIR Study on Structure Changes of Coal Kerogen in the Maturation Process. Bulletin of Mineralogy, Petrology and Geochemistry, 32(1): 97-101 (in Chinese with English abstract). http://d.wanfangdata.com.cn/Periodical/kwysdqhxtb201301008 [12] Lu, S.F., Zhang, M., Zhong, N.N., 2007. Oil and Gas Geochemistry. Petroleum Industry Press, Beijing (in Chinese). [13] Lu, S.N., Zhang, G., 1994. A New Genesis Mode of Condensate. Science in China (Series B), 24(1): 81-86 (in Chinese). [14] Ma, K.Y., Fan, P., 1995. Geochemical Evidence of Evaporation Fractionation Condensate of Sha18 Well in Northern Tarim Basin. Chinese Science Bulletin, 40(19): 1785-1787 (in Chinese). doi: 10.1360/csb1995-40-19-1785 [15] Mango, F.D. 1990. The Origin of Light Hydrocarbons in Petroleum: A Kinetic Test of the Steady-State Catalytic Hypothesis. Geochimica et Cosmochimica Acta, 54(5): 1315-1323. doi: 10.1016/0016-7037(90)90156-F [16] Mukhopadhyay, P.K., Dow, W.G., 1994. Vitrinite Reflectance as a Maturity Parameter: Applications and limitations. American Chemical Society, Washington D.C.. [17] Snowdon, L.R., Powell, T.G., 1982. Immature Oil and Condensate: Modification of Hydrocarbon Generation Model for Terrestrial Organic Matter. AAPG Bulletin, 66(6): 775-788. http://www.researchgate.net/publication/216539208_Immature_oil_and_condensate_-_Modification_of_hydrocarbon_generation_model_for_terrestrial_organic_matter [18] Su, A., Chen, H.H., Wang, C.W., et al., 2013. Genesis and Maturity Identification of Oil and Gas in the Xihu Sag, East China Sea Basin. Petroleum Exploration and Development, 40(5): 521-527 (in Chinese with English abstract). http://d.wanfangdata.com.cn/Periodical/syktykf201305002 [19] Su, A., Chen, H.H., Wang, C.W., et al., 2014. Source of Natural Gas in Xihu Depression of the East China Sea Basin. Geological Science and Technology Information, 33(1): 157-162 (in Chinese with English abstract). http://www.en.cnki.com.cn/Article_en/CJFDTotal-DZKQ201401025.htm [20] Thompson, K., 1987. Gas Condensate Migration and Oil Fractionation in Deltaic Systems. Marine and Petroleum Geology, 5(3): 237-246. doi: 10.1016/0264-8172(88)90004-9 [21] Tissot, B.P., Welte, D.H., 1978. Petroleum Formation and Occurrence. Springer, Berlin. [22] Yang, C.P., Geng, A.S., Liao, Z.W., et al., 2009. Quantitative Gas Washing Evaluation on Reservoirs in Tazhong Area of Tarim Basin. Science in China (Series D), 39(1): 51-60 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-TDKX200905010.htm [23] Zhang, G.C., Miao, S.D., Chen, Y., et al., 2013. Distribution of Gas Enrichment Regions Controlled by Source Rocks and Geothermal Heat in China Offshore Basins. Natural Gas Industry, 33(4): 1-17 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-TRQG201304002.htm [24] Zhang, S.C., 2000. The Migration Fractionation: An Important Mechanism in the Formation of Condensate and Waxy Oil. Chinese Science Bulletin, 45(6): 667-670 (in Chinese). doi: 10.1360/csb2000-45-6-667 [25] Zhang, Z.H., Huang, Z.L., Zhang, Z.Y., et al., 2004. Geochemical Characteristics and Origin of High-Wax Condensate and High-Gravity Oil in the Western Turpan-Hami Basin. Acta Geologica Sinica, 78(4): 551-559 (in Chinese with English abstract). http://www.researchgate.net/publication/286315039_Geochemical_characteristics_and_origin_of_high-wax_condensate_and_high-gravity_oil_in_the_western_Turpan_-_Hami_Basin [26] Zhu, Y.M., Zhou, J., Gu, S.X., et al., 2012. Molecular Geochemistry of Eocene Pinghu Formation Coal-Bearing Source Rocks in the Xihu Depression, East China Sea Shelf Basin. Acta Petrolei Sinica, 33(1): 32-39 (in Chinese with English abstract). http://www.researchgate.net/publication/286062882_Molecular_geochemistry_of_Eocene_Pinghu_Formation_coal-bearing_source_rocks_in_the_Xihu_Depression_East_China_Sea_Shelf_Basin [27] 陈建平, 黄第藩, 李晋超, 等, 1999. 西北地区侏罗纪煤系有机质成烃模式. 地球化学, 28(4): 327-339. doi: 10.3321/j.issn:0379-1726.1999.04.003 [28] 傅宁, 李友川, 陈桂华, 等, 2003. 东海西湖凹陷油气"蒸发分馏"成藏机制. 石油勘探与开发, 2: 39-42. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK200302012.htm [29] 龚德瑜, 李明, 李启明, 等, 2014. 塔里木盆地乌什凹陷原油地球化学特征及油源分析. 天然气地球科学, 25(1): 62-69. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201401009.htm [30] 侯启军, 冯子辉, 霍秋立, 2004. 海拉尔盆地乌尔逊凹陷石油运移模式与成藏期. 地球科学——中国地质大学学报, 29(4): 397-403. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200404003.htm [31] 贾健谊, 须雪豪, 孙伯强, 2000. 东海西湖凹陷原油与天然气的地球化学特征. 海洋石油, 20(2): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-HYSY200002000.htm [32] 雷闯, 叶加仁, 吴景富, 等, 2014. 低勘探程度盆地成藏动力学过程: 以西湖凹陷中部地区为例. 地球科学——中国地质大学学报, 39(7): 837-847. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201407006.htm [33] 李贤庆, 钟宁宁, 熊波, 等, 1997. 西湖凹陷煤系源岩的有机质热演化研究. 中国煤田地质, 9(1): 33-36. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGMT701.009.htm [34] 李岩, 王云鹏, 赵长毅, 等, 2013. 煤中干酪根在热演化中结构变化的红外光谱研究. 矿物岩石地球化学通报, 32(1): 97-101. doi: 10.3969/j.issn.1007-2802.2013.01.008 [35] 卢双舫, 张敏, 钟宁宁, 2007. 油气地球化学. 北京: 石油工业出版社. [36] 卢松年, 张刚, 1994. 一种新的凝析油形成模式. 中国科学(B辑), 24(1): 81-86. https://www.cnki.com.cn/Article/CJFDTOTAL-JBXK199401012.htm [37] 马柯阳, 范璞, 1995. 塔北沙18井石炭系蒸发分馏成因凝析油确认的地球化学证据. 科学通报, 40(19): 1785-1787. doi: 10.3321/j.issn:0023-074X.1995.19.015 [38] 苏奥, 陈红汉, 王存武, 等, 2013. 东海盆地西湖凹陷油气成因及成熟度判别. 石油勘探与开发, 40(5): 521-527. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201305003.htm [39] 苏奥, 陈红汉, 王存武, 等, 2014. 东海盆地西湖凹陷天然气来源探讨. 地质科技情报, 33(1): 157-162. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ201401025.htm [40] 杨楚鹏, 耿安松, 廖泽文, 等, 2009. 塔里木盆地塔中地区油藏气侵定量评价. 中国科学(D辑), 39(1): 51- 60. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200901005.htm [41] 张功成, 苗顺德, 陈莹, 等, 2013. "源热共控"中国近海天然气富集区分布. 天然气工业, 33(4): 1-17. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201304002.htm [42] 张水昌, 2000. 运移分馏作用: 凝析油和蜡质油形成的一种重要机制. 科学通报, 45(6): 667-670. doi: 10.3321/j.issn:0023-074X.2000.06.024 [43] 张枝焕, 黄志龙, 张振英, 等, 2004. 吐哈盆地西部地区高蜡凝析油和轻质油的地球化学特征及成因分析. 地质学报, 78(4): 551-559. doi: 10.3321/j.issn:0001-5717.2004.04.015 [44] 朱扬明, 周洁, 顾圣啸, 等, 2012. 西湖凹陷始新统平湖组煤系烃源岩分子地球化学特征. 石油学报, 33(1): 32-39. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201201003.htm -
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