【作者】 耿新华；

【导师】 耿安松；

【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， 2006， 博士

【摘要】 我国海相碳酸盐岩烃源岩的特点是有机质丰度低、热成熟度高、经历的地质历史较长、研究难度大。有关碳酸盐岩生烃演化机理以及其成烃潜力、资源评估一直是关注的问题。本研究利用黄金管限定体系对碳酸盐岩烃源岩进行生烃动力学模拟,计算了气液态组分的生烃动力学参数,并在此基础上提出了适合我国海相碳酸盐岩的生烃定量模型。 通过对低熟碳酸盐岩全岩样品与其干酪根进行生烃动力学热模拟条件试验,表明全岩和干酪根样品的气态烷烃具有相似的动力学参数。干酪根的分离对动力学参数的求取几乎没有影响。 对低熟碳酸盐岩干酪根进行生烃动力学模拟实验,分析了海相碳酸盐岩热解气液态产物演化特征并分别计算了各组分的动力学参数。结果表明,在按一般情况设定的地质条件下,海相碳酸盐岩热解生成气态烃的主要温度为150℃-220℃(Easy%Ro介于1.0%-3.0%),液态烃的生成温度主要为100℃-170~C(Easy%Ro介于0.5%-1.5%),并应用其热解动力学参数准确的提出了适合我国的海相碳酸盐岩的生烃定量模型。 通过对碳酸盐岩Ⅱ型干酪根裂解生成的油来进行分子级生烃动力学模拟实验,揭示了油在裂解成气过程中气态烃产物的演化特征,建立并标定油裂解成气的化学动力学模型。和干酪根裂解生气相比,原油裂解生气滞后于干酪根降解生气,滞后Easy%Ro0.3以上。 对济阳坳陷下古生界Ⅱ型干酪根进行二次生烃动力学研究,推导出各类产物的生烃动力学参数,与低熟干酪根生烃动力学参数进行对比并应用于济阳坳陷的古地温演化史中,在此基础上对该地区的生烃史进行了研究。结果表明,在济阳坳陷整个生烃过程存在两次生烃,由低成熟度样品恢复的第二次生烃过程与直接用已经历过一次生烃过程的成熟度较高的样品进行实验得出的二次生烃结果相似,二次生烃未见有迟滞性。运用实验数据对济阳坳陷下古生界碳酸盐岩的甲烷生气量进行粗略的计算,结果表明,碳酸盐岩烃源岩经二次深埋后可再次生气而成为一种有效的气源岩。更多还原

【Abstract】 The thick marine carbonate rocks spread widely in China. It is characterized by low TOC, high maturity and long geological history. There is no obvious development in the exploration of oil & gas in the carbonate strata up to now. Therefore, more works are needed for the assessment of carbonate source rocks in China. In order to evaluate the marine carbonate source rocks objectively and determine the exploration direction, it is necessary to develop new method and set up a new identification and evaluation criterion for evaluating quantitatively the effective marine carbonate source rocks. Little work has been done on the kinetics of hydrocarbon generation of the marine carbonate source rocks at present in China. Therefore, it is important to investigate and assess the carbonate source rocks for the further exploration of oil and gas resources in China. In this paper, the kinetic parameters of hydrocarbon generation from the marine carbonate rocks are calculated through kinetic simulating experiment and the quantitative models of oil and gas generation are proposed.Based on the pressurized pyrolysis simulation experiments of the marine carbonate source rocks and the isolated kerogens, the kinetic parameters of methane and C_2-5 generation were determined. The result shows that the marine carbonate source rocks and the isolated kerogens exhibited very similar kinetic parameters. It is suggested that kerogen isolation to be or not to be necessary should depend on the basic geochemical data of the study sample.Through the pressurized pyrolysis simulation experiments of the marine carbonate source rocks, the evolution characteristics of gas and liquid products are discussed systematically . The results show that the kinetic parameters of hydrocarbon generation of C₁, C₂, C₃, C_4-5, C_6-13 and C₁₃+are 44-68, 65-79, 70-83, 84-95, 51-67 and 56-68 Kcal/mol, respectively. The kinetic parameters of hydrocarbon generation wereextrapolated from geological conditions by using a relative software. It indicates that gaseous hydrocarbons （Ci,C2,C3,C4.5,） generate in condition of 150°C < T< 220°C （1.0% <Easy%J?o < 3.0%）. Light hydrocarbons （C6-i3） and heavy hydrocarbons （C）3+) generate in condition of 100°C < T< 170°C （0.5% < Easy%Ro < 1.5%）.The evolution characteristics of gas generating by oil which prepared from the marine carbonate source rocks have been investigated. The results shows that Easy%7?o is 1.2—2.9% during the methane generation period and Easy%i?o is 1.5%—2.5% during the C2-5 hydrocarbon gas generation period. Compared to the marine carbonate source rocks, the gas generation of oil is lagged and the degree of lagging is about 0.3%.Kinetic simulating experiment on lower palaeozoic marine carbonate rocks in the Jiyang Depression were carried out. The kinetic parameters of hydrocarbon generation were determined and were compared to the kinetic parameters which generated from the samples with low maturity. Extrapolating these parameters to the geological condition in the Jiyang Depression, hydrocarbon generation history was simulated. Results show that the two samples exhibited similar process of the secondary hydrocarbon generation and there is no lagging of the re-generation. A rough estimation is made for the maximum methane generation intensity of the lower palaeozoic marine carbonate rocks in the Jiyang Depression. It shows that the lower palaeozoic marine carbonate rocks can be effective gas source rocks when the source rocks re-subsided and fell into the second hydrocarbon.更多还原