Based on experimental data from hydrocarbon generation with a semi-open system, hydrocarbon generation kinetics modeling in gold tube of closed system, high temperature pyrolysis chromatography mass spectrometry exper...Based on experimental data from hydrocarbon generation with a semi-open system, hydrocarbon generation kinetics modeling in gold tube of closed system, high temperature pyrolysis chromatography mass spectrometry experiment with open system and geological data, the characteristics of whole hydrocarbon-generating process, hydrocarbon expulsion efficiency and retained hydrocarbon quantity, origins of natural gas generated in high-over mature stage and cracking temperature of methane homologs were investigated in this study. The sapropelic source rock has a hydrocarbon expulsion efficiency of 30%-60% and 60%-80% in the major oil generation window(with Ro of 0.8%-1.3%) and high maturity stage(with Ro of 1.3%-2.0%) respectively; and the contribution ratio of kerogen degradation gas to oil cracking gas in total generated gas in high maturity stage is about 1:4. The degradation gas of kerogen accounts for 20%, the retained liquid hydrocarbon cracking gas accounts for 13.5%, and the amount of out-reservoir oil cracking gas(including aggregation type and dispersed oil cracking gas) accounts for 66.5%. The lower limit of gas cracking is determined preliminarily. Based on the new understandings, a model of the whole hydrocarbon-generating process of source rock is built.展开更多
采用MS(Materials Studio 2017)软件中Forcite模块,对自主构建的抚顺油页岩干酪根二维结构模型进行能量最小化分子动力学模拟,通过能量最优化过程得到干酪根初始优化结构。在此基础上进行分子动力学退火模拟,获得全局能量最优化构型,即...采用MS(Materials Studio 2017)软件中Forcite模块,对自主构建的抚顺油页岩干酪根二维结构模型进行能量最小化分子动力学模拟,通过能量最优化过程得到干酪根初始优化结构。在此基础上进行分子动力学退火模拟,获得全局能量最优化构型,即油页岩干酪根分子三维结构模型。基于密度泛函理论的量子力学模拟方法,计算分析干酪根三维结构模型的动力学、键能、键级、电荷密度等参数,分析化学活性位点,探讨了干酪根热解微观化学演化机理,进而预测了反应性。展开更多
有机质及其相关孔隙吸附行为的研究对于揭示页岩油赋存状态与机理有重要意义。不同于以往采用石墨烯模型代替有机质的方法,研究采用真实的干酪根分子模型(Ⅱ-C型),基于GAFF(general Amber force field)力场模拟了有机孔内页岩油多组分...有机质及其相关孔隙吸附行为的研究对于揭示页岩油赋存状态与机理有重要意义。不同于以往采用石墨烯模型代替有机质的方法,研究采用真实的干酪根分子模型(Ⅱ-C型),基于GAFF(general Amber force field)力场模拟了有机孔内页岩油多组分体系下的吸附行为。结果表明:(1)与石墨烯仅能模拟壁面吸附不同,干酪根对页岩油具有吸附和吸收双重作用:壁面上存在页岩油竞争吸附,以极性和重质组分吸附为主,而骨架中则存在页岩油组分吸收现象,小分子迁移距离较远。页岩油在干酪根壁面上的吸附和在骨架中的迁移受控于页岩油与干酪根相互作用能的强弱及分子大小,重质组分表现出“强吸附-弱吸收”、轻质组分呈“弱吸附-强吸收”的特征。(2)页岩油组分的吸收使得干酪根骨架和孔隙发生变化,表现出新孔隙的形成、原有孔隙的扩大和部分塌陷。干酪根的塑性对吸收页岩油进而膨胀起重要作用,干酪根塑性较强时(干酪根成熟度低),页岩油更容易被吸收从而引发明显的干酪根骨架膨胀,反之,干酪根膨胀较弱。(3)温度增加会促进干酪根骨架吸收芳香烃分子萘和非极性分子甲酸、乙醇以及噻吩,降低干酪根壁面的吸附作用,同时有利于饱和烃类分子的脱附。压力对页岩油在干酪根中的吸附和吸收影响不明显。研究利用真实的干酪根分子模型,首次创新性地模拟了干酪根吸附和吸收页岩油组分的现象,对于客观揭示页岩油在干酪根中赋存状态及赋存机理具有重要帮助。展开更多
基金Supported by the National Science and Technology Major Project(2016ZX05007-003,2011ZX05007-002)
文摘Based on experimental data from hydrocarbon generation with a semi-open system, hydrocarbon generation kinetics modeling in gold tube of closed system, high temperature pyrolysis chromatography mass spectrometry experiment with open system and geological data, the characteristics of whole hydrocarbon-generating process, hydrocarbon expulsion efficiency and retained hydrocarbon quantity, origins of natural gas generated in high-over mature stage and cracking temperature of methane homologs were investigated in this study. The sapropelic source rock has a hydrocarbon expulsion efficiency of 30%-60% and 60%-80% in the major oil generation window(with Ro of 0.8%-1.3%) and high maturity stage(with Ro of 1.3%-2.0%) respectively; and the contribution ratio of kerogen degradation gas to oil cracking gas in total generated gas in high maturity stage is about 1:4. The degradation gas of kerogen accounts for 20%, the retained liquid hydrocarbon cracking gas accounts for 13.5%, and the amount of out-reservoir oil cracking gas(including aggregation type and dispersed oil cracking gas) accounts for 66.5%. The lower limit of gas cracking is determined preliminarily. Based on the new understandings, a model of the whole hydrocarbon-generating process of source rock is built.
文摘采用MS(Materials Studio 2017)软件中Forcite模块,对自主构建的抚顺油页岩干酪根二维结构模型进行能量最小化分子动力学模拟,通过能量最优化过程得到干酪根初始优化结构。在此基础上进行分子动力学退火模拟,获得全局能量最优化构型,即油页岩干酪根分子三维结构模型。基于密度泛函理论的量子力学模拟方法,计算分析干酪根三维结构模型的动力学、键能、键级、电荷密度等参数,分析化学活性位点,探讨了干酪根热解微观化学演化机理,进而预测了反应性。
文摘有机质及其相关孔隙吸附行为的研究对于揭示页岩油赋存状态与机理有重要意义。不同于以往采用石墨烯模型代替有机质的方法,研究采用真实的干酪根分子模型(Ⅱ-C型),基于GAFF(general Amber force field)力场模拟了有机孔内页岩油多组分体系下的吸附行为。结果表明:(1)与石墨烯仅能模拟壁面吸附不同,干酪根对页岩油具有吸附和吸收双重作用:壁面上存在页岩油竞争吸附,以极性和重质组分吸附为主,而骨架中则存在页岩油组分吸收现象,小分子迁移距离较远。页岩油在干酪根壁面上的吸附和在骨架中的迁移受控于页岩油与干酪根相互作用能的强弱及分子大小,重质组分表现出“强吸附-弱吸收”、轻质组分呈“弱吸附-强吸收”的特征。(2)页岩油组分的吸收使得干酪根骨架和孔隙发生变化,表现出新孔隙的形成、原有孔隙的扩大和部分塌陷。干酪根的塑性对吸收页岩油进而膨胀起重要作用,干酪根塑性较强时(干酪根成熟度低),页岩油更容易被吸收从而引发明显的干酪根骨架膨胀,反之,干酪根膨胀较弱。(3)温度增加会促进干酪根骨架吸收芳香烃分子萘和非极性分子甲酸、乙醇以及噻吩,降低干酪根壁面的吸附作用,同时有利于饱和烃类分子的脱附。压力对页岩油在干酪根中的吸附和吸收影响不明显。研究利用真实的干酪根分子模型,首次创新性地模拟了干酪根吸附和吸收页岩油组分的现象,对于客观揭示页岩油在干酪根中赋存状态及赋存机理具有重要帮助。
