论文部分内容阅读
华北地区中上元古界地层烃源岩的有机质热演化普遍处于高成熟-过成熟阶段,而张家口下花园青白口系下马岭组页岩和灰质页岩的Rb仅有0.38～0.6％,处于低成熟阶段,是系统研究中上元古界地层的生烃模式及有机质热演化特征的较理想模拟实验样品。本次模拟结果表明:模拟温度在27.5℃以前（R。<0.80％）为低成熟阶段,275℃～350℃（R0为0.8～1.32％）为成熟阶段;其中325℃（R0为1.16％）为生油高峰,350℃（R0为1.32％）为轻质油高峰,350℃～410℃（R0为1.32～2.0％）为高成熟阶段,410℃以后（R0>2.0％）为过成熟阶段。随着温度升高,生成的烃类和干酪根碳同位素（δ13C）逐渐变重,验证了δ13C存在温阶效用。在过成熟阶段,可溶有机质亦发生了芳核的缩聚反应,使芳烃含量减少,大分子的沥青质含量增多。可溶有机质在高成熟-过成熟阶段有“逆转”现象,正构烷烃碳数分布出现了双主峰,高碳数部位出现了奇偶优势等特征。当Rb>0.81％以后,同一温度点的Rb％>R。％。无水与加水模拟实验对比表明,加水实验的液态烃产率高,液态烃中重组分相对含量多,说明无水实验中热裂解反应强烈,而加水实验更接近地层热演化条件。
The organic matter thermal evolution of the source rocks in the Middle and Upper Proterozoic strata in North China is generally at a high mature-maturity stage, while the Rb of shale and gray shale in the Xiamaling Formation of the Qingbaikou System in Zhangjiakou Lower Gardens is only 0.38-0.6% The low maturity stage is a relatively ideal simulated experimental sample of the hydrocarbon generation mode and the thermal evolution characteristics of organic matter in the Upper Proterozoic strata during systematic study. The simulation results show that the simulated temperature is low maturity stage before 27.5 ℃ (R. <0.80%), mature stage at 275 ℃ ~ 350 ℃ (R0 0.8 ~ 1.32%), and 325 ℃ (R0 = 1.16% In order to generate oil peak, the peak of light oil was at 350 ℃ (R0 = 1.32%), high maturity at 350 ℃ ~ 410 ℃ (R0 = 1.32 ~ 2.0%) and over maturity after 410 ℃ . As the temperature increases, the hydrocarbon and kerogen carbon isotopes (δ13C) gradually become heavier, which confirms the existence of temperature-stage utility of δ13C. In the mature stage, soluble organic matter also occurs aromatic nucleus polycondensation reaction, so that aromatic content decreased, macromolecules increased asphaltene content. Soluble organic matter has a “reversal” phenomenon in the high ripening-maturation stage. The double peak appears in the carbon number distribution of n-alkanes and the odd-even advantages appear in the high-carbon parts. When Rb> 0.81%, the same temperature point Rb%> R. %. Comparison of water and water simulation shows that the high yield of liquid hydrocarbon and the relative content of heavy components in liquid hydrocarbon indicate that the thermal cracking reaction is intense in anhydrous experiment and the water adding experiment is closer to the thermal evolution of formation.