Abstract
Hydrocarbons, include heavy oils, normal oils, waxy oils and light oils, condensate oils and gases were all found in Lunnan Oilfield, the occurrences of hydrocarbons with complicated physical properties indicates a complicated distribution of reservoirs. By the drilling data, the distribution pattern had been found that, in plan view, the density of crude oils in the western part is heavier than that of oils in the eastern part in Lunnan region, namely the crude oils were mainly found in the western part while the natural gases were mainly found in the eastern, which shows that an obvious differentiation in the east and west part was presented in the Lunnan region. Furthermore, in vertical view, the light hydrocarbons were mainly found in the Carboniferous reservoir while the heavier hydrocarbons were mainly found in the Ordovician and Triassic reservoirs. By analysis of the semi-logarithm distribution ofn-alkanes, biomarker ratios and stable carbon isotopic compositions of crude oils, we have found that two oil families and discontinuous distribution were presented in hydrocarbons in Lunnan Oilfield. This kind of discontinuous distribution of geochemical parameters was not from continuous fractionation in migration process. The biodegraded heavy oil reservoirs in western part belong to the lower matured oil family, while the light or condensate oils reservoirs belong to higher matured oil family. Thus, a mixed filling of hydrocarbons was occurred in the middle part in Lunnan Oilfield and resulted in the occurrence of waxy oil. The mixed filling model may help to explain the distribution pattern of hydrocarbon reservoirs in Lunnan Oilfield, especially can lead to a relatively consistent explanation for all kinds of geochemical data, such as physical properties, pyrrolic nitrogen compounds, biomarker parameters and stable carbon isotopic compositions.
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References
Huang Difan, Zhao Mengjun, Characteristics and genetic analysis of the high waxy and low sulfur marine crude oils in Tarim Basin, NW China, in Advances of Petroleum Geology in Tarim Basin, NW China (eds. Tong Xiaoguang, Liang Digang, Jia Chengzao), Beijing: Science Press, 1996.
Huang Difan, Zhao Mengjun, Zhang Shuichang, Genetic analysis of the origin of the lower Paleozoic waxy hydrocarbon from the Manjiar oil-gas system, Tarim Basin, Acta Sedimentologica Sinica (in Chinese), 1997, 15: 6–13.
Luo Binjie, Fu Jiamo, Fan Pu et al., Hydrocarbons Generation in Tarim Basin, NW China, Research Report for State Key Project of Science and Technology for Hydrocarbon Exploration in Tarim Basin (in Chinese), 1995.
Ma Keyang, Zhou Yonghong, Shen Jianzhong, Behavior of light hydrocarbons in crude oils under the gas-liquid dissolution equilibrium: potential significance in Tarim Basin, NW China, Acta Sedimentologica Sinica (in Chinese), 1995, 13(4): 100–108.
Ma Keyang, Fan Pu, Wang Hongshan, Geochemical evidence for the recognition of the Carboniferous condensate by evaporative fractionation from Tabei Sha-18 well, Chinese Science Bulletin, 1996, 41(5): 405–409.
Ma Keyang, Evaporation fractionation: a new mechanism for generation of condensate oils, Advances in Earth Sciences (in Chinese), 1995, 10(6): 567–571.
Ma Keyang, Geochemistry of marine oils in Tarim Basin, NW China, Acta Geology Sinica in Gansu Province (in Chinese), 1997, 6: 80–83.
Liang Digang, Zhang Shuichang, Wang Feiyu et al., Source rocks and source kitchen in Tarim Basin, NW China, Research Report for State Key Project of Science and Technology for hydrocarbon Exploration in Tarim Basin (in Chinese), 1998.
Zhang Shuichang, Migration fractionation: an important mechanism of generation of condensate oils and waxy oils, Chinese Science Bulletin (in Chinese), 2000, 45(6): 667–670.
Chen Yicai, Shen Zhongmin, Li Yanjun et al., Characteristics and formation mechanism analysis of petroleum pools in the Lunnan Low Uplift of the Tarim Basin, Bulletin of Chengdu Institute of Technology (in Chinese), 2002, 29(5): 483–486.
Lu Hong, Sun Yongge, Peng Ping’an, Occurrences and implications of aryl isoprenoids detected in the crude oils from Lunnan Oilfield, Tarim Basin, NW China, Geological Journal of China University (in Chinese), 2004, 10(2): 283–289.
Lu Hong, Genetic analysis of diversity in crude oil types in Lunnan Oilfeild, Tarim Basin, NW China: molecular and stable carbon isotope approaches (in chinese), Postdoctor Research Report, Geochemistry Institute of Chinese Academy of Sciences, 2002.
Peng Ping’an, Lü Xiuxiang, Wang Feiyu et al., Stage Research Report of State Key Project 973 for Exploration in Lunnan Oilfield (in Chinese), 2004.
Zhou Fengying, Sun Yushan, Zhang Shuichang, Path, period and direction of hydrocarbon migration in Lunnan Oilfeild, Tarim Basin, NW China, Geologic Review (in Chinese), 2001, 47(5): 329–335.
Kissin, Y., Catagenesis and composition of petroleum: origin ofn-alkanes and isoalkanes in petroleum crude oils, Geochimica et Cosmochimica Acta, 1987, 51: 2445–2457.
Meulbroek, P., Lawrence, C., Whelan, J. K., Phase fractionation at South Island Block 330, Organic Geochemistry, 1998, 29: 223–239.
Meulbroek, P., MacLeod, G., PVT properties in exploration, Organic Geochemistry, 2002, 33(6): 611–612.
Losh, S., Cathles, L., Meulbroek, P., Gas washing of oil along a regional transect, offshore Louisiana, Organic Geochemistry, 2002, 33: 655–663.
Rassamdana, H., Farhani, M., Dabir, B. Et al., Asphalt flocculation and deposition, V. Phase behavior in miscible and immiscible injections, Energy & Fuels, 1999, 13: 176–187.
Thompson, K. F. M., Fractionated aromatic petroleum and the generation of gas-condensates, Organic Geochemistry, 1987, 11: 573–590.
Thompson, K. F. M., Gas-condensate migration and oil fractionation in deltic systems, Marine and Petroleum Geology, 1988, 5: 237–246.
Wang Tieguan, Li Sumei, Zhang Aiyun et al., Hydrocarbons migration analysis by pyrrolic nitrogen compounds, Acta Geologica Sinica, 2000, 74(1): 85–92.
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Lu, H., Jia, W., Xiao, Z. et al. Constraints on the diversity of crude oil types in the Lunnan Oilfield, Tarim Basin, NW China. Chin. Sci. Bull. 49 (Suppl 1), 19–26 (2004). https://doi.org/10.1007/BF02890449
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DOI: https://doi.org/10.1007/BF02890449