【摘要】 为了解压力对有机质热演化和成烃过程的影响,利用高压生烃模拟仪,在一定半开放体系中,对采自钻孔的泥质烃源岩样品进行了恒压与增压2个系列的生烃模拟实验。恒压系列中,沥青、热解油和气态烃产率高峰分别出现在350℃、520℃和520℃,产率依次为6.17mg/g、12.07mg/g和4.14mL/g,对应镜质体反射率(R_O)分别为0.9%、3.0%和3.0%,排烃次数分别为4次、21次和21次。增压系列中,沥青、热解油和气态烃产率高峰分别出现在350℃、500℃和520℃,产率依次为12.56mg/g、24.87mg/g和2.59mL/g,对应R_O值分别为1.1%、3.1%和3.1%,对应排烃次数分别为5次、43次和44次。表明在半开放体系中,排烃次数受到温度和排烃压力阈值的共同控制,温度升高引起生烃强度增加,在同一排烃压力阈值条件下,体系内压力不断上升,达到排烃压力阈值上限,导致排烃次数增加,而排烃次数增加可能有利于液态烃的形成。流体压力的升高可能会促进沥青和热解油的形成,导致液态烃产率升高。同时,流体压力的升高也可能不利于气态烃的形成,会降低气态烃产率。流体压力对有机质R_O值的影响在不同温度阶段不尽相同,400~500℃区间R_O值随流体压力升高明显增加。更多还原

【Abstract】 In order to investigate the process of thermal evolution and hydrocarbons generation of organic matter.Mudstone source rock from drilling was pyrolyzed in simulation with con-pressure and hetero-pressure experiments in semi-open system high pressure instrument.In con-pressure experiments,peak of bitumen,oil,gaseous hydrocarbon yields appeared at 350℃,520℃ and 520℃ respectively,and yields were,in order,6.17mg/g,12.07mg/g and 4.14mL/g.The corresponding R_Oof residues were 0.9%,3.0% and 3.0%.Times of expelling hydrocarbon were,in order 4,21 and 21.In hetero-pressure experiments,peak of bitumen,oil,gaseous hydrocarbon yields appeared at 350℃,500℃ and 520℃respectively,and yields were,in order,12.56mg/g,24.87mg/g and 2.59mL/g.The corresponding R_Oof residues were 1.1%,3.1% and3.1%.Times of expelling hydrocarbon were,in order 5,43 and 44.Results demonstrate that the times of expelling hydrocarbon were controlled by temperature and threshold of expulsion hydrocarbon pressure.Increasing simulation temperature might enhance hydrocarbon generation intensity,and causing the pressure in the reactor reached the upper limit of the threshold of expulsion hydrocarbon pressure constantly under the same threshold of expulsion hydrocarbon pressure condition,times of expelling hydrocarbon were enhanced at last.And it might promote source rocks yielding liquid hydrocarbons.Increasing the fluids pressure might enhance ource rocks yielding bitumen and oil,increasing the yield of liquid hydrocarbons.At the same time,increasing fluid pressure might reduce the yield of gaseous hydrocarbons,causing the negative influence of gaseous hydrocarbons generation.The influence of fluids pressure to R_Ois different in different temperature,400-500℃,enlarging R_O of organic matter with increasing fluid pressure may be more obvious.更多还原