【摘要】 有机质成熟过程中,可溶有机质在页岩中赋存状态的演化规律对于深入了解页岩油气的储集空间具有重要意义。采用压机半封闭体系,对低成熟的鄂尔多斯长7段页岩进行了不同温度条件下的高压热模拟实验研究,获取了一系列成熟度梯度（0.7%<VRo<3.5%）的页岩样品。通过混合溶剂（CH₂CL₂﹕CH₃OH=93﹕7）进行索氏抽提,结合低压N₂和CO₂气体吸附实验对抽提前后页岩孔隙特征进行了对比研究,得出以下认识:去除可溶有机质的页岩的TOC含量、吸附烃S₁、热解烃S₂、氢指数IH在成熟阶段（VRo<2.0%）都有明显的降低,但在过成熟阶段（VRo>2.0%）差异较小且相对稳定;可溶有机质对微孔的影响可能以覆盖遮掩为主,对页岩孔体积的影响主要集中在介孔和大孔部分,但对页岩比表面积的影响主要集中在微孔和介孔范围。更多还原

【Abstract】 Extractable organic matter in shales has great significance to shale gas reservoirs during thermal maturation. A semi-closed thermal simulation was conducted on Chang-7 shales at different temperatures to acquire a set of shale samples at a thermal gradiant range from VRo = 0.7% to VRo = 3.5%. And extractable organic matter is characterized according to the comparison study of the shale pore characteristics investigated by low-pressure N₂ and CO₂ adsorption techniques on different scales before and after solvent extraction. The results show that the TOC, S₁, S₂ and IH of the extracted samples tend to decrease significantly with increasing maturity until VRo = 2.0%, then generally become stable at higher maturation level. Solvent extraction may cover the micro-pores mainly and dramatically enhance the volumes of meso-and macro-pores, but only slightly enhance the micro-pore volume. In comparison, the increase of specific surface area after solvent extraction may be mostly contributed by micro-pores, and then by meso-pores.更多还原