Fluid Inclusion Record Oil Cracking Temperature: Case Study of the Shuijingtuo Formation in the Yichang Area, Hubei
-
摘要: 原油裂解气是中国南方海相页岩气的主要来源之一，确定原油向天然气转化的温度对页岩气成藏研究具有重要意义。前人主要基于生烃模拟实验和动力学方程来模拟原油裂解的温度条件，但是依然缺乏直接的地质记录。本次研究通过对湖北宜昌地区水井沱组页岩中白云石脉和方解石脉流体包裹体岩相学观察、显微测温和激光拉曼光谱等手段来识别代表早期原油裂解的沥青+气两相包裹体，通过其同期盐水包裹体的均一温度来约束原油向湿气裂解的温度。结果表明早期油包裹体形成在白云石脉充填之后、方解石脉充填之前，与其伴生的盐水包裹体平均均一温度指示原油裂解的最低温度为142.1 ℃。分析认为，研究区白云石脉形成于加里东晚期至海西晚期，原油快速裂解成气在海西运动晚期（300 Ma）开始，方解石脉则形成于燕山早期（140~120 Ma）；鄂西地区水井沱组台内冩湖区由于缺乏岩家河组沉积，构造作用造成水井沱组早期形成页岩油气沿白云石脉向下进入灯影组顶部白云岩储层，对寒武系页岩气成藏以及天然气成藏具有重要的制约作用。Abstract: Gas from oil cracking is one of the main sources of marine shale gas in South China. Determination of the temperature of oil cracking into gas is of great significance to the study of the process of shale gas accumulation. Previously, the temperature conditions of oil cracking were mainly based on hydrocarbon simulation experiments and dynamic equations, but the direct geological records are still not sufficient. Through petrographic observation, microthermometry and laser Raman spectroscopy, this study has identified the existence of the bitumen-bearing gas-liquid inclusions, indicative of early oil cracking and restricts the cracking temperature with the homogenization temperatures of the coevally trapped aqueous inclusions. The results show that the early-stage oil inclusions have been trapped later than the precipitation of dolomites and earlier than that of the calcites filling the veins, with the coeval aqueous inclusions homogenizing at 142.1℃, which indicates the lowest cracking temperature of the crude oil. Combined with other information, it is deduced that the dolomite has been precipitating from the late Caledonian to the late Hercynian orogeny, during which point the oil started cracking rapidly (300 Ma). Calcite veins have been formed at the early stage of the Yanshan orogeny (140~120 Ma). The Shuijingtuo formation in the lagoon facies in south Hubei lacks the deposition of Yanjiahe formation, therefore caused by tectonic movements, the migration of early shale oil generated from the Shuijingtuo formation into the dolomite reservoir of the uppermost part of the Dengying formation through dolomite veins, which provides essential constraints to the shale gas accumulation and other natural gas accumulation in the Cambrian strata.
-
Key words:
- shale gas /
- oil cracking /
- marine shale /
- Shuijingtuo formation /
- the Yichang area, Hubei
-
-
[1] 陈孝红,危 凯,张保民,李培军,李 海,刘 安,罗胜元.2018.湖北宜昌寒武系水井沱组页岩气藏主控地质因素和富集模式[J].中国地质,45(2): 207-226.
[2] 樊 茹,邓胜徽,张学磊.2011.寒武系碳同位素漂移事件的全球对比性分析[J].中国科学:地球科学,41(12):1829-1839.
[3] 房忱琛,熊永强,李 芸,梁前勇,陈 媛.2015.原油裂解过程中固体沥青的拉曼光谱演化特征[J].地球化学,44(2):196-204.
[4] 葛 翔,沈传波,梅廉夫.2016.低温热年代对黄陵隆起中新生代古地形的约束[J].大地构造与成矿学,40(4):654-662.
[5] 郭彤楼,李国雄,曾庆立.2005.江汉盆地当阳复向斜当深3井热史恢复及其油气勘探意义[J].地质科学,40(4): 570-578.
[6] 胡作维,黄思静,李志明,Qing Hairuo,范 明,兰叶芳.2012.川东北地区三叠系飞仙关组白云化流体温度[J].中国科学:地球科学,42(12):1817-1829.
[7] 湖北省地质调查院.2007.1⁚25万宜昌市幅区域地质调查报告[R].26-133.
[8] 李天义,何 生,何治亮,沃玉进,周 雁,王芙蓉,杨兴业.2012.中扬子地区当阳复向斜中生代以来的构造抬升和热史重建[J].石油学报, 33(2): 213-224.
[9] 刘秀岩,陈红汉,张洪安,徐田武.多套烃源岩联合供烃下的原油成藏特征及其与压力的耦合关系：以东濮凹陷濮城地区沙河街组为例[J].地球科学, 2020, 45(6): 2210-2220.
[10] 罗胜元,陈孝红,刘 安,李 海.2019.中扬子宜昌地区下寒武统水井沱组页岩气地球化学特征及其成因[J].石油与天然气地质,40(5):999-1010.
[11] 罗胜元,陈孝红,岳 勇,李培军,蔡全升,杨睿之.2020.中扬子宜昌地区沉积-构造演化与寒武系页岩气富集规律[J].天然气地球科学, 31(8):1052-1068.
[12] 罗胜元,刘 安,李 海,陈孝红,张 淼.2019.中扬子宜昌地区寒武系水井沱组页岩含气性及影响因素[J].石油实验地质, 41(1): 56-67.
[13] 沈传波,梅廉夫,刘昭茜,徐思煌.2009.黄陵隆起中-新生代隆升作用的裂变径迹证据[J].矿物岩石, 29(2): 54-60.
[14] 许露露,文剑航,温雅茹,王 亿,张焱林,谢 通,任志军,罗 凡,胡江龙.2021.中扬子鄂西地区海相页岩气地质特征及找矿成果综述[J].资源环境与工程,35(5):611-624.
[15] 张建坤,何 生,易积正,张柏桥,张士万,郑伦举,侯宇光,王 亿.2014.岩石热声发射和盆模技术研究中扬子区西部下古生界海相页岩最高古地温和热成熟史[J].石油学报,35(1): 58-67.
[16] 曾雄伟,王传尚,刘 安,危 凯. 2016.湖北宜昌地区中寒武统天河板组沉积相及其油气意义[J].华南地质与矿产, 32(2): 142-148.
[17] Liu X Y, Chen H H, Xiao X W, Zhang H A, Wang Y, Xu T, Shang P, Kong L. 2020. Overpressure evolution recorded in fluid inclusions in the Dongpu Depression, Bohai Bay Basin, North China [J]. Journal of Earth Science, in press.
[18] Liu X Y, Chen H H, Xiao X W, Zhang H A, Xu T W. 2020. Mixing characteristics of oil inclusions with different thermal maturities in the Wenliu Uplift, Dongpu Depression, Bohai Bay Basin, North China [J]. Journal of Earth Science, 31(6): 1251-1258.
[19] Mangenot X, Tarantola A, Mullis J, Girard J P, Eiler J M. 2021. Geochemistry of clumped isotopologues of CH4 within fluid inclusions in Alpine tectonic quartz fissures [J]. Earth and Planetary Science Letters, 561: 116792.
[20] Nie H K, He Z L, Wang R Y, Zhang G R, Chen Q, Li D H, Lu Z Y, Sun C X. 2020. Temperature and origin of fluid inclusions in shale veins of Wufeng-Longmaxi Formations, Sichuan Basin, south China: Implications for shale gas preservation and enrichment [J]. Journal of Petroleum Science and Engineering, 193: 107329.
[21] Tan J Q, Horsfield B, Mahlstedt N, Zhang J C, Di Primio R, Vu T A T, Boreham C J, Van Graas G, Tocher B A. 2013. Physical properties of petroleum formed during maturation of Lower Cambrian shale in the upper Yangtze Platform, South China, as inferred from PhaseKinetics modelling [J]. Marine and Petroleum Geology, 48: 47-56.
[22] Wang Q R, Huang H P, Chen H H, Zhao Y T. 2020. Secondary alteration of ancient Shuntuoguole oil reservoirs, Tarim Basin, NW China [J]. Marine and Petroleum Geology, 111: 202-218.
[23] Zhao W Z, Zhang S C, Zhang B, He K, Wang X M. 2017. New insight into the kinetics of deep liquid hydrocarbon cracking and its significance [J]. Geofluids, 2017: 1-11.
-
计量
- 文章访问数: 945
- PDF下载数: 76
- 施引文献: 0
下载: