Pyrolysis of oil at high temperatures: Gas potentials, chemical and carbon isotopic signatures
Pyrolysis of oil at high temperatures: Gas potentials, chemical and carbon isotopic signatures
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高温下石油热解：气体势、化学和碳同位素特征
DOI：
10.1007/s11434-008-0590-0
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发表时间：
2009-01
期刊：
影响因子：
--
通讯作者：
Shen JiaGui
中科院分区：
文献类型：
--
作者：
Xiao XianMing;Lu YuHong;Xiao ZhongYao;Tian Hui;Yang LiGuo;Guo LiGuo;Shen JiaGui
尽管石油裂解气已被认为是高成熟海相盆地的重要来源之一，但对其资源潜力、化学和同位素组成仍存在一些争议。本研究以塔里木盆地中部塔中TZ62井志留系海相原油样品为研究对象，采用封闭式连续热解和分步半开式热解两种不同的热解方案，对寒武系海相原油样品进行了热解实验。结果表明，在EasyRo=2.3%时，C_1-5气体的重量产率最大，此时剩余气势仅为43.4毫升/克，约为EasyRo=2.3%时产气量361毫升/克的12%。结合动力学模拟结果，认为原油裂解产气的主要阶段为EasyRo=1.6%~2.3%。在封闭体系中，当EasyRo&Gt；2.3%时，C_1-5气体体积产率的增加主要与以前形成的C_2-5湿气的再裂化有关，而不是与油的直接裂化有关。分步热解实验表明，渣油裂解气具有很高的干度指数(大于92%)和−28.7%~−26.7%的重甲烷碳同位素值，与封闭系统连续裂解气有很大不同。甲烷碳同位素分馏动力学模拟表明，在2°C/Ma的地质升温速率下，天然气生成主期(EasyRo<；2.3%)甲烷的碳同位素远轻于前驱油的碳同位素。上述观测结果为高成熟海相盆地油气资源的准确识别和客观评价提供了新的线索。
Although the gas cracked from oil has been believed to be one of the important sources in highly matured marine basins, there are still some debates on its resource potentials and chemical and isotopic compositions. In this study a Cambrian-sourced marine oil sample from the Silurian reservoir of well TZ62 in the central Tarim basin was pyrolyzed using sealed gold tubes with two different pyrolysis schemes: continuous pyrolysis in a closed system and stepwise semi-open pyrolysis. The results show that the maximum weight yield of C1–5gases occurs at EasyRo=2.3% and the residual gas potential after this maturity is only 43.4 mL/g, about 12% of the yield of 361 mL/g at EasyRo=2.3%. Combined with the results of kinetic modeling, the main stage of gas generation from oil cracking is believed within the EasyRo=1.6%–2.3%. The increase in the volume yield of C1–5gases at EasyRo>2.3% in a closed system is mainly related to the re-cracking of previously formed C2–5wet gases, not the direct cracking of oil. The stepwise pyrolysis experiments show that the gas from the cracking of residual oil at EasyRo>2.3% is characterized by very high dryness index (higher than 92%) and heavy methane carbon isotopes ranging from −28.7% to −26.7%, which is quite different from the gases from the continuous pyrolysis in a closed system. The kinetic modeling of methane carbon isotope fractionation shows that the carbon isotopes of methane within the main stage of gas generation (EasyRo<2.3%) are far lighter than the carbon isotopes of the precursor oils under a geological heating rate of 2 °C/Ma. The above observations and results provide some new clues to the accurate recognition and objective resource evaluation of oil cracking gas in highly mature marine basins.
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影响因子：
3
作者：
Hill, RJ;Tang, YC;Kaplan, IR
通讯作者：
Kaplan, IR
影响因子：
4.2
作者：
H. Tian;X. Xiao;R. Wilkins;Xianqing Li;Huajun Gan
通讯作者：
H. Tian;X. Xiao;R. Wilkins;Xianqing Li;Huajun Gan
影响因子：
--
作者：
Xie Zeng-ye;Tian Shi-cheng
通讯作者：
Xie Zeng-ye;Tian Shi-cheng
影响因子：
--
作者：
Ling Wenli;Shan Gao;Haifei Zheng;Lian Zhou;Z. Zhao
通讯作者：
Ling Wenli;Shan Gao;Haifei Zheng;Lian Zhou;Z. Zhao
影响因子：
3.5
作者：
Hill, Ronald J.;Zhang, Etuan;Tang, Yongchun
通讯作者：
Tang, Yongchun