【作者】 田静；

【导师】 王云鹏；

【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， 2007， 硕士

【摘要】 本论文的研究工作着重于以下几个问题：煤和海相页岩的生烃能力如何?主生烃期和生烃速率是什么?煤和海相页岩的排烃时机、机理和特征是什么?煤及海相页岩残余生烃潜力及二次裂解生烃特征是什么?各章节也基本按照这些问题展开。本研究主要进行了煤及海相页岩的初次生烃动力学实验，全岩热模拟排烃实验和不同母质的生气动力学研究。取得的主要成果如下：本论文通过生烃动力学模拟实验得出海相页岩比煤具有更大的生烃能力，不仅生烃速率大，而且生烃持续的时间也长。主生烃期分别为：海相页岩Ro(％)=0.71～1.1％、煤Ro(％)=0.72～1.23％；在升温速率为5℃／Ma情况下，主生烃期对应的地质温度范围分别为海相126～160.5℃、煤128～168.5℃；海相页岩主生烃期范围比煤岩窄。通过利用更接近实际地质情况的块状样品进行排烃模拟实验，可以看出煤和海相页岩都是先达到生烃高峰，后达到排烃高峰，煤中残留烃的量要比海相页岩大，其吸附能力比海相页岩的强，因此煤中的烃更不容易排出；海相源岩的主排烃期为Ro=0.7-1.26％，煤的主排烃期为Ro=0.71-1.3％；升温速率对残留烃的影响也很大，升温速率快，加热的时间短，排出烃量相对比较少，所以残留的烃就比较多。海相页岩的氢指数(HI)要比煤的大，说明海相页岩的生油能力要比煤的强；海相的排烃率要比煤的大，这是因为煤的吸附性比较强，排烃效率要小一些。不同的升温速率对排烃率也有一定的影响，慢速升温下的排烃率变化要比快速升温下变化慢，但是二者的变化曲线是基本一致的，说明对于煤和海相页岩来说，母质不同是造成其排烃率存在差距的根本原因。通过生排烃和二次裂解生气的比较，可以发现：高过成熟阶段海相地层主要是以排出的油藏或输导层中原油裂解气为主。在排烃结束之前(Ro＜1.3％)，煤成气有两个来源，一是初始的干酪根生成的气，二是生成的液态烃裂解成气。在排烃结束以后(Ro＞1.3％)，煤本身生成的气很少，煤成气大部分来自于排出的油裂解气。我们通过生烃，排烃和生气三者结合来看，川东北地区下二叠统进入生排烃比较晚的地区，排烃率比较小，残留烃量比较大，所以生气强度比较大，就比较容易形成好的残余烃裂解型气源灶。高效气源灶主要位于开县-达县-平昌-渠县-梁平一线。更多还原

【Abstract】 This paper is focusing on the following questions: What is the hydrocarbon generating capability of coal and marine shale? What are their main hydrocarbon generating stages and generating rates? What are the main hydrocarbon expulsion stages, mechanism and characteristics of coal and marine shale? What are the hydrocarbon generation potentials and their secondary cracking characteristics for coal and marine shale? The following chapters will answer these questions one by one. The kinetic experiments of primary hydrocarbon generation of coal and marine shale, whole rock expulsion and the gas generation kinetics of different precursors are performed in this paper.The kinetic experimental results of hydrocarbon generation indicate that the hydrocarbon generating capability of marine shale is larger than that of coal, not only in much higher hydrocarbon generating rate, but also in much longer hydrocarbon generating time. The main hydrocarbon generating stage of coal is Ro(%)=0.72-1.23%, while marine shale is Ro(%)=0.71-1.1%. In the geologic heating rate of 5℃/Ma, the corresponding geologic temperatures of main hydrocarbon generating period are 126-160.5℃for marine shale and 128-168.5℃for coal respectively, which shows that marine shale’s main hydrocarbon generating period is narrower than that of coal.A lumpy rock sample is used in the generation-expulsion experiment in order to truly simulate the real geological condition. It can be found that both coal and marine shale reach hydrocarbon generation peak firstly and then hydrocarbon expulsion peak afterwards. The quantity of retained hydrocarbon in coal is larger than that of marine shale. This increases the difficulty of hydrocarbon generated in coal to be expulsed because coal’s absorbability is stronger than marine shale’s. The main hydrocarbon expulsion stage is Ro=0.7-1.26% for marine shale and Ro=0.71-1.3% for coal. The quantities of retained hydrocarbon in marine shale and coal are also affected by heating rate. In the case of fast heating rate, the expulsed quantity of the hydrocarbon will decrease which leads to the increase of retained hydrocarbon.The Hydrogen Index (HI) of marine shale is larger than that of coal, which indicates that the hydrocarbon generation capability of marine shale is larger than that of coal. In addition, marine shale’s hydrocarbon expulsion rate is higher than coal’s for the reason that coal has strong absorbability, which hinders its expulsion efficiency. The hydrocarbon expulsion rate is also affected by the heating rate. The results show that it changes quickly under faster heating rate. However, both fast and slow heating rates show the same change trend, which indicates that the precursor is the major control for causing different hydrocarbon expulsion efficiency fundamentally.It can be found after comparing the hydrocarbon generation, expulsion and secondary cracking to gas that the main source of natural gas is from secondary cracking of oil in the reservoirs and the conducting strata in high-over maturation marine strata, The coal-associated gas generated from hydrocarbon-expulsion has two resources before expulsion (Ro<1.3%): one is the gas generated by primary cracking of kerogen, another is from the generated liquid oil before expulsion. After the hydrocarbon expulsion (Ro<1.3%), the coal associated gases are mainly from the natural gas generated from cracking of oil.In view of generation, expulsion and secondary cracking gas, the lower Permian of northeast Sichuan was taken as an evaluation target. Calculating results show that the hydrocarbon generation and expulsion time is relatively late and the hydrocarbon expulsion efficiency is low. The secondary gas generation intensity is very larger due to the large quantity of retained hydrocarbons in marine source rocks, which is easier to form the good retained-hydrocarbon-type gas source kitchen. The high effective gas source kitchens are located in the areas along Kaixian, Daxian, Pingchang, Quxian and Liangping.更多还原