库车坳陷煤成甲烷碳同位素动力学研究

2004年 25卷 第No.1期
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Kinetic study of carbon isotope in humic gas methane in Kuqa depression
李贤庆 肖贤明 Tang Y 米敬奎 申家贵 肖中尧 包建平 熊波
Li Xianqing Xiao Xianming Tang Y Mi Jingkui Shen Jiagui Xiao Zhongyao Bao Jianping Xiong Bo
应用黄金管封闭体系热解实验,结合GCIRMS同位素质谱仪的甲烷碳同位素分析,研究了塔里木盆地库车坳陷侏罗系煤生成甲烷的碳同位素特征及其动力学模拟。结果表明,库车坳陷侏罗系煤热解气甲烷碳同位素介于-36%~-25%;碳同位素与热解温度(或)、升温速率密切相关;煤成甲烷的碳同位素动力学模拟结果与热解实验数据吻合较好,表明可以用动力学方法将实验数据外推,并应用于地质实际中。模拟结果显示,库车坳陷克拉2气田天然气主要经历了10Ma(尤其是5Ma)以来的阶段性聚集。
The characteristics and kinetic modeling of carbon isotope of methane in Jurassic humic gas in Kuqa depression in Tarim basin have been studied by combining pyrolysis experiment in closed gold tube system and analysis of methane isotope with GC-IRMS isotope mass spectrograph.The carbon isotope ranges between -3.6%~-2.5% and is closely related to pyrolysis temperature (or vitrinite reflectance Ro) and heating rate. Kinetic simulation results of carbon isotope in humic gas methane are in good agreement with the experimental data, thus the experimental data can be extrapolated through kinetic modeling and applied to actual geological conditions. Simulation results show that natural gas in Kela 2gas field in Kuqa depression has mainly experienced episodic accumulation since 10 Ma (especially 5 Ma).
煤成甲烷; 热解实验; 碳同位素; 动力学模拟; 天然气成因; 库车坳陷;
humic gas methane; pyrolysis experiment; carbon isotope; kinetic modeling; origin of natural gas; Kuqa depression;
10.11743/ogg20040104