【作者】 帅燕华；

【导师】 彭平安； 邹艳荣；

【作者基本信息】 中国科学院研究生院（广州地球化学研究所） ， 地球化学， 2004， 博士

【摘要】 有机质(干酪根)裂解生烃动力学模拟是以Arrenium方程为基础发展起来的、能够很好模拟有机质生烃的一种技术手段。目前，常用的模型都是基于干酪根裂解生烃由一系列相互独立平行一级反应组成的假设基础上。各种模型的主要区别在于活化能分布函数的不同，而指前因子，没有特别的意义，只作为调和参数存在，可以简化为统一的值。 同位素动力学模拟是以生烃动力学模拟为基础发展起来的，它可以动态地再现地质历史过程中热解甲烷的碳同位素演化特征。因此，可为气藏的成藏历史恢复提供非常重要的信息。目前的同位素动力学模型以Lorant模型、Cramer模型和Tang模型为代表。本论文在实现各模型的基础上，对各自的特点、优缺点、使用限制进行了简单的评价。 限定体系，湿气组分存在着生-裂的平衡。本论文建立了限定体系湿气组分模拟技术，为一些参数的地质应用提供了可能；并结合甲烷碳同位素动力学模拟的特点，发展了限定体系下乙烷等湿气组分的碳同位素模拟技术。多参数的联合应用，对于恢复快速沉陷盆地中气藏的成藏历史具有非常重要的意义，它可以弥补单纯依赖甲烷同位素数值获得多种解释的不足，并可以弥补甲烷碳同位素容易受各种次生作用影响而发生变化的缺憾，为天然气成藏研究提供一种互相左证，互相支持及相互弥补的方法。 在初次运移、扩散、水洗等各种后生、次生作用过程中，天然气的特征和数量会发生变化。因此，对于一些成藏较早的气藏，其成藏历史的恢复，必须要考虑后生、次生因素的影响。本文对这些因素造成的影响进行了研究，并通过数值模拟的手段，对影响程度进行了界定。 通过对鄂尔多斯盆地上古生界煤热解动力学实验研究与数据模拟，证明鄂尔多斯盆地上古生界天然气主要来源于上古生界煤的长期裂解累积；而盆地中部长庆气田区下古生界马家沟组五段的天然气以下古生界来源为主，上古生界煤成天然气只占26.7％；上古生界煤自白垩纪以来处于生烃停止状态，长期的扩散大约使30％的天然气损失，扩散损失的天然气富含轻碳甲烷，湿气含量少；水洗使大约8％的煤成气损失，损失的天然气在同位素特征上基本没有发生变化，却富含湿气组分(2％)。两种过程对于残余天然气特征影响较小，基本可忽略不计；初次运移过程中，以煤的吸附作用为主的各种物理作用使大量的湿气组分滞留在煤中，排出的天然气富集甲烷。 动力学模拟结果证明塔里木盆地库车凹陷克拉2气藏天然气主要来自于中生代Abstraet煤系源岩的长期裂解一累积、累积阶段在上新世末期结束。圈闭形成之前由煤系源岩形成的天然气主要储集在煤系源岩及碎屑岩夹层组成的气囊带中;上新世末期，天然气充注中断的原因在于强烈的构造运动使气藏构造内发生构造高压环境。更多还原

【Abstract】 Kinetic modeling of the hydrocarbons generation from organic matter’s cracking is a useful method in reconstructing the history of petroleum generation in a basin. The kinetic models commonly used are proposed that the reactions of hydrocarbon generation from kerogen are parallel and independent. They should have the same exponential parameter, but distinguish themselves with different reaction energies. Because of the complexity of the mechanism of the real reactions, the exponential parameters are only an adjust factors without any physical chemistry significances.The progress of kinetic models of hydrocarbons generation promotes the technique to accurately simulate the stable carbon isotope ratio of methane. Kinetics could model the stable carbon isotope ratio of methane in the geological history. Therefore, it could help to assess how and when a gas accumulating. Up to date, Cramer model and Tang model are two models that are accepted in the world. In this Dissertation, those two models are implemented and their characters are analyzed. Also, the kinetics simulation of the stable carbon isotope ratios of other heavy gaseous components in confined system is made out. The usage of it, accompany with that of methane, could give much more accurate result in rebuilding the formation of a gas, especially a gas in a complex geological surrounding.The characters and quality of natural gases is changeful in many geological progresses, including primary migration, diffusion, water washing, bacterial activity. That made the formation information of natural gases changeable too. So, to analyze the formation of a gas should take into consideration of all those factors. In this paper, the quality and characters of the lost gas during the second processes are kinetically modeled.The modeling results based on pyrolysis experiments of Upper Paleozoic coal showed that gases in Upper Paleozoic reservoir are derived from those coals with a long time cracking history. In Ordovician reservoir, 70% of gases are from Low Paleozoic marine organic matter, and about 30% are coal-formed gas. During long time diffusion from the formation of coal-formed gas, about 30% gases rich in methane have escaped through the cap rocks, therefore, the gases left in reservoir became wet with much more heavy gaseous components. But the variance in the stable carbon isotope ratios of gas in reservoir is very inconspicuous. During water washing, about 10% coaled-gas has been lost with much more heavy gaseous components. Also, the modified characters of leaving parts are inconspicuous too. The primary migration of gases from source rock to reservoir rock makes more heavy gaseous parts leaving in the coal, because of the preferential adsorption of the coal for heavy gaseous components than for methane.Modeling results including stable carbon isotope ratios of both methane and ethane showed that gases in Kela 2 gas field are accumulated from coal burial to the end of KuqaIIIstage of Cenozoic. The earlier gas generated from coal before the formation of Kela 2 structure was adsorbed in the coal measures. The accumulation of gases finished at the end of Kuqa stage (2 Ma B.P.), because of strong structural deformation of Kuqa depression, which made some faults cut off the thick salt cap rocks.The primary migration of gases from source rock to reservoir rock in these two basins showed different degree in depleting of heavy gaseous components because of the different maturity of their mother rocks.更多还原