南苏丹Melut盆地北部坳陷烃源岩热演化特征及油气地质意义

doi:10.3969/j.issn.1672-7703.2020.06.008

摘要/Abstract

摘要： 南苏丹Melut 盆地烃源岩热演化特征研究对盆地油气勘探具有指导意义。通过地质、地球化学资料分析及含油气系统模拟技术，在恢复北部坳陷热史基础上，利用“Easy% R o”动力学模拟方法模拟计算了Renk 组烃源岩的成熟史，同时利用“R o—排烃率”模型对Renk 组的生排烃史进行了研究。结果表明，北部坳陷的3 个凹陷 Renk 组烃源岩热演化程度存在一定差异，Jamous 凹陷进入成熟、高成熟、过成熟的时间最早，Ruman 凹陷次之， Moleeta 凹陷最晚。由于热演化史的差异，导致北部坳陷的3 个凹陷在生排烃时间上也具有一定差异性，Jamous 凹陷在白垩世晚期（88Ma）开始排烃，在古新世进入大规模排烃阶段，而Ruman 凹陷及Moleeta 凹陷进入大规模排烃阶段的时间在始新世。整体而言，北部坳陷烃源岩生排烃时间与Yabus/Samma 组、Galhak 组与Gayger 组圈闭、盖层形成时间有良好的匹配关系，影响Yabus/Samma 组成藏的主控因素是油源断裂，而Gayger 组与Galhak 组成藏的主控因素是储层物性。同时热演化程度高、持续排烃的Renk 组烃源岩为北部坳陷地层—岩性油藏的油气充注提供了丰富的物质基础。因此，地层—岩性油藏应为北部坳陷重要的勘探接替领域，值得进一步研究探索。

关键词: 热演化, 烃源岩, 油气成藏, 盆地模拟, Melut 盆地

Abstract: Study of the thermal evolution characteristics of source rocks in the Melut Basin in South Sudan is of great significance for oil and gas exploration in the basin. Following the restoration of thermal history of the Northern depression, the maturity history of source rocks in the Renk Formation was simulated using the “Easy% Ro” dynamic simulation method combined with the analysis of geological and geochemical data, and petroleum system modeling. Also, the hydrocarbon generation and expulsion history of the source rocks was studied by “Ro - hydrocarbon expulsion rate” model. The results show that there are some differences in the thermal evolution degrees of Renk Formation source rocks between the three sags in the Northern depression. The source rocks in the Jamous sag were the earliest to enter the mature, high mature, and over mature stages, followed by those in the Ruman sag. Source rocks in the Moleeta sag were the most recent. Due to these differences in thermal evolution history, there are also some differences in hydrocarbon generation and expulsion times between the three sags. Source rocks in the Jamous sag began to expel hydrocarbon in the late Cretaceous (88 Ma) and entered the large-scale hydrocarbon expulsion stage in the Paleocene. In the Ruman and Moleeta sags, large-scale hydrocarbon expulsion occurred in the Eocene. Overall, the hydrocarbon generation and expulsion times of source rocks in the Northern depression have a good matching relationship with the formation times of the traps and cap rocks of the Yabus/Samma Formation, Galhak Formation, and Gayger Formation. The main controlling factor for hydrocarbon accumulation in the Yabus/Samma Formation is oil-source connecting faults, while in the Gayger and Galhak Formations it is reservoir physical properties. The source rocks in the Renk Formation, with a high degree of thermal evolution and continuously expelling hydrocarbon, provide a rich material basis for oil and gas charging into stratigraphic-lithologic reservoirs in the Northern depression. Therefore, stratigraphic-lithologic reservoirs should be an important replacement area for future exploration in the Northern depression and deserving of further research and exploration.

中图分类号:

薛罗, 史忠生, 马轮, 陈彬滔, 王磊, 马凤良, 史江龙. 南苏丹Melut盆地北部坳陷烃源岩热演化特征及油气地质意义[J]. 中国石油勘探, 2020, 25(6): 79-86.

Xue Luo, Shi Zhongsheng, Ma Lun, Chen Bintao, Wang Lei, Ma Fengliang, Shi Jianglong. Thermal evolution characteristics of source rocks in the Northern depression of the Melut Basin, South Sudan, and their petroleum geological significance[J]. China Petroleum Exploration, 2020, 25(6): 79-86.

参考文献

[1] 石广仁．油气盆地数值模拟方法[M]. 北京：石油工业出版社，2004: 1-2. Shi Guangren. Numerical simulation methods of oil-gas basin[M]. Beijing: Petroleum Industry Press, 2004:1-2.
[2] Welte D H. Petroleum origin and accumulation in basin evolution: a quantitative model[J]. AAPG Bull, 1981,65(8):1387-1396.
[3] Nakayama K, VanSiclin D C. Simulation model for petroleum exploration[J]. AAPG Bull, 1981,65(7):1230-1255.
[4] 段威，侯宇光，何生，等．澳大利亚波拿巴盆地侏罗系烃源岩热史及成熟史模拟[J]. 地质科技情报，2011,30(3):65-71. Duan Wei, Hou Yuguang, He Sheng, et al . Jurassic source rock thermal and maturity history modelling in the Bonaparte Basin of Australia[J]. Geological Science and Technology Information, 2011,30(3):65-71.
[5] 宗奕，邹华耀，于开平．辽东湾地区古近系烃源岩热演化模拟[J]. 天然气工业，2010,30(7):21-24. Zong Yi, Zou Huayao, Yu Kaiping. Thermal evolution simulation of the Paleogene source rocks in the Liaodong Bay area[J]. Natural Gas Industry, 2010,30(7):21-24.
[6] 李日容．油气成藏动力学模拟现状与展望[J]. 石油实验地质，2006, 28(1):78-82. Li Rirong. The development and prospect in the simulation of petroleum pool-forming dynamics[J]. Petroleum Geology & Experiment, 2006,28(1):78-82.
[7] 刘金萍，王改云，王嘹亮，等．北黄海东部次盆地油气成藏主控因素[J]. 石油与天然气地质，2015,36(6):888-896. Liu Jinping, Wang Gaiyun, Wang Liaoliang, et al . Main controlling factors of hydrocarbon accumulation in the Eastern Sub-basin, North Yellow Sea[J]. Oil & Gas Geology, 2015, 36(6):888-896.
[8] 关德范，徐旭辉，李志明，等．成盆成烃成藏理论思维与有限空间生烃模式[J]. 石油与天然气地质，2008,29(6):709-715. Guan Defan, Xu Xuhui, Li Zhiming, et al . A study on theories of basin evolution and hydrocarbon generation and accumulation and model of hydrocarbon generation in finite spaces[J]. Oil & Gas Geology, 2008,29(6):709-715.
[9] 高岗．油气生成模拟方法及其石油地质意义[J]. 天然气地球科学， 2000,11(2):25-19. Gao Gang. Method of petroleum-generating simulation and petroleum geological significance[J]. Natural Gas Geoscience, 2000,11(2):25-19.
[10] 童晓光，徐志强，史卜庆，等．苏丹迈卢特盆地石油地质特征及成藏模式[J]. 石油学报，2006,27(2):1-10. Tong Xiaoguang, Xu Zhiqiang, Shi Buqing, et al . Petroleum geologic property and reservoir-forming pattern of Melut Basin in Sudan[J]. Acta Petrolei Sinica, 2006,27(2):1-10.
[11] 窦立荣．苏丹迈努特盆地油气成藏机理和成藏模式[J]. 矿物岩石地球化学通报，2005,24(1):50-57. Dou Lirong. Formation mechanism and model of oil and gas accumulations in the Melut Basin, Sudan[J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2005,24(1):50-57.
[12] 窦立荣，潘校华，田作基，等．苏丹裂谷盆地油气藏的形成与分布：兼与中国东部裂谷盆地对比分析[J]. 石油勘探与开发，2006,33(3): 255-261. Dou Lirong, Pan Xiaohua, Tian Zuoji, et al . Hydrocarbon formation and distribution of rift basins in Sudan: a comparative analysis of them with rift basins in East China[J]. Petroleum Exploration and Development, 2006,33(3):255-261.
[13] 叶先灯．苏丹Melut 盆地构造、沉积和油气成藏研究[D]. 中国科学院研究生院（广州地球化学研究所），2006. Ye Xiandeng. Study on tectonics, sedimentology and reservoirs in Melut Basin, Sudan[D]. Guangzhou Institute of Geochemistry Chinese Academy of Sciences, 2006.
[14] Chull T J. Rift basins of interior Sudan: petroleum exploration and discovery[J]. AAPG Bulletin, 1988,72(10):1128-1142.
[15] McHargue T R, Heidrick T L, Livingston J K. Tectonostratigraphic development of the interior Sudan rifts, Central Africa[J]. Tectonophysics, 1992,213(1/2):187-202.
[16] Jorgensen G J, Bosworth W. Gravity modeling in the central African rift system, Sudan: rift geometries and tectonic significance[J]. Journal of African Earth Science, 1989,8 (2/3/4): 283-306.
[17] 王国林，史忠生，赵艳军，等．南苏丹Melut 盆地北部地区岩性油藏成藏条件及勘探启示[J]. 岩性油气藏，2018,30(4):37-45. Wang Guolin, Shi Zhongsheng, Zhao Yanjun, et al . Lithological oil reservoir forming conditions and its exploration implication in northern Melut Basin, South Sudan[J]. Lithological Reservoirs, 2018,30(4):37-45.
[18] 王民，卢双舫，董奇，等．有机质生烃动力学模型对比[J]. 中国石油大学学报( 自然科学版)，2011,35(3):12-18. Wang Min, Lu Shuangfang, Dong Qi, et al . Comparision on hydrocarbon generation kinetic models[J]. Journal of China University of Petroleum, 2011,35(3):12-18.
[19] 苏玉平，付晓飞，卢双舫，等．EASY% R o 法在滨北地区热演化史中的应用[J]. 大庆石油学院学报，2006,30(2):5-8. Su Yuping, Fu Xiaofei, Lu Shuangfang, et al . Application of Easy% R o model to the research of thermal evolution in Binbei[J]. Journal of Daqing Petroleum Institute, 2006,30(2):5-8.
[20] 张磊，孟元林，崔存萧，等．氢抑制条件下的有机质热演化动力学模型：以三塘湖盆地芦草沟组为例[J]. 石油与天然气地质，2017, 38(5):862-868. Zhang Lei, Meng Yuanlin, Cui Cunxiao, et al . A new kinetic model of organic thermal evolution under the condition of hydrogen suppression: a case study from the Lucaogou Formation in the Santanghu Basin[J]. Oil & Gas Geology, 2017,38(5): 862-868.
[21] 史忠生，王天奇，方乐华，等．从类比中探索Muglad 与Melut 两大盆地勘探潜力与转型[J]. 中国石油勘探，2014,19(2):67-76. Shi Zhongsheng, Wang Tianqi, Fang Lehua, et al . Study exploration potential and transformation of Muglad Basin and Melut Basin on basis of analogy[J]. China petroleum exploration, 2014,19(2):67-76.
[22] McKenzie D P. Some remarks on the development of sedimentary basins[J]. Earth and Planetary Science Letters, 1978,40:25-32.
[23] Mohamed A Y, Pearson M J, Ashcroft W A, et al . Modeling petroleum generation in the southern Muglad Rift Basin, Sudan[J]. AAPG, 1999,83(12):1943-1964.
[24] Mohamed A Y, Iliffe J E, Ashcroft W A, et al . Burial and maturation history of the Heglig field area, Muglad Basin, Sudan[J]. Journal of Petroleum Geology, 2000,23(1):107-128.
[25] Schwarzer D, Littke R. Petroleum generation and migration in the‘Tight Gas’area of the German Rotliegend natural gas play: a basin modelling study[J]. Petroleum Geosciences, 2007, 13(1):37-62.
[26] Peters K E, Magoon L B, Bird K J, et al . North Slope, Alaska: source rock distribution, richness, thermal maturity and petroleum charge[J]. AAPG Bulletin, 2006,90(2):261-292.
[27] 史忠生，薛罗，牛慧赟，等．中非Melut 盆地远源岩性油藏成藏条件与勘探对策[J]. 中国石油勘探，2017,22(6):87-95. Shi Zhongsheng, Xue Luo, Niu Huiyun, et al . Accumulation conditions of far-source lithologic reservoirs and exploration strategy in Melut Basin, Central Africa[J]. China Petroleum Exploration, 2017,22(6):87-95.
[28] 陈云林．论富油洼陷及其意义[J]. 勘探家，1999,4(2):8-11. Chen Yunlin. Concept of oil-rich subsag and its significance[J]. Petroleum Explorationist, 1999,4(2):8-11.
[29] 贾承造，赵文智，邹才能，等．岩性地层油气藏地质理论与勘探技术[J]. 石油勘探与开发，2007,34(3):257-272. Jia Chengzao, Zhao Wenzhi, Zou Caineng, et al . Geological theory and exploration technology for lithostratigraphic hydrocarbon reservoirs[J]. Petrolem Exploration and Development, 2007,34(3): 257-272.
[30] 张宇，邱贻博，贾光华，等．中国东部富油凹陷高效勘探历程与启示：以济阳坳陷博兴洼陷为例[J]. 中国石油勘探，2018,23(5):21-27. Zhang Yu, Qiu Yibo, Jia Guanghua, et al . Efficient exploration process and enlightenment of oil-rich sags in eastern China: a case study on the Boxing subsag in Jiyang depression[J]. China Petroleum Exploration, 2018,23(5):21-27.
[31] 米立军，张向涛，丁琳，等．海上成熟探区中浅层岩性油气藏分布特点与勘探策略：以珠江口盆地惠州凹陷为例[J]. 中国石油勘探， 2018,23(6):10-19. Mi Lijun, Zhang Xiangtao, Ding Lin, et al . Distribution characteristics and exploration strategy of middle-shallow lithologic reservoirs in offshore mature exploration areas: a case study on Huizhou sag in the Pearl River Mouth Basin[J]. China Petroleum Exploration, 2018,23(6):10-19.
[32] 骆卫峰，余文端，马晓东，等．苏北盆地海安凹陷南部岩性油藏勘探成果及启示[J]. 中国石油勘探，2018,23(3):56-63. Luo Weifeng, Yu Wenduan, Ma Xiaodong, et al . Exploration achievement of lithological oil reservoirs in the south of Haian depression, the Subei Basin and its enlightenment[J]. China Petroleum Exploration, 2018,23(3):56-63.
[33] 周心怀，高顺莉，高伟中，等．东海陆架盆地西湖凹陷平北斜坡带海陆过渡型岩性油气藏形成与分布预测[J]. 中国石油勘探，2019, 24(2):153-164. Zhou Xinhuai, Gao Shunli, Gao Weizhong, et al . Formation and distribution of marine-continental transitional lithologic reservoirs in Pingbei slope belt, Xihu sag, East China Sea Shelf Basin[J]. China Petroleum Exploration, 2019,24(2):153-164.
[34] 李鹭光，何海清，范土芝，等．中国石油油气勘探进展与上游业务发展战略[J]. 中国石油勘探，2020,25(1):1-10. Li Luguang, He Haiqing, Fan Tuzhi, et al . Oil and gas exploration progress and upstream development strategy of CNPC[J]. China Petroleum Exploration, 2020,25(1):1-10.